Aviation Rulemaking

Advisory Committee

Fuel Tank

Harmonization Working

Group

Final Report

Submitted jointly by

AIA, AECMA, ATA, ALPA, IATA, FAA, JAA, GAMA, API

ARAC

JAA FAA

THE PUBLIC

July 1998

J

A

A

oint

viation

uthorities

FAA

Air Transport Association of America

Aerospace

 Industries

Association
FUEL TANK HARMONIZATION WORKING GROUP

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Executive Summary

The overall goal of the aviation industry and the regulatory agencies is to enhance

aircraft safety in an effective and practical manner. The Fuel Tank Harmonization

Working Group has spent the last six months aggressively pursuing means to improve

airplane safety by reducing flammability in fuel tanks. The group investigated the

history of the commercial fleet to understand the significance of each event involving

fuel tank flammability, and to look for underlying causes that would assist our

investigation. Thermal analyses of a wide range of airplanes operating in worldwide

environmental conditions were used to correlate the historical record with the

flammability exposure of fuel tanks, and to evaluate potential solutions.

The industry and the FAA have already taken actions to:

• Identify and correct equipment and installations that have the potential to

be an ignition source in a fuel tank through service bulletins and

Airworthiness Directives,

• Develop and execute inspection programs to assess the conditions of the

fuel systems in the fleet and to develop maintenance programs based on

those inspection results,

• Initiate work on a Special Federal Aviation Regulation (SFAR) to review

system design and certification, and maintenance practices, with the goal of

reducing the probability of ignition sources occurring in fuel tanks,

• Establish the Fuel Tank Harmonization Working Group (FTHWG) to

investigate means to reduce or eliminate explosive mixtures in fuel tanks.

This comprehensive effort is attempting to address both ignition sources in the fuel

system and exposure to flammable fuel-air mixtures.

The FTHWG studies showed that flammability exposure varies among airplane types

and depends on fuel tank location. Some fuel tanks (e.g., wing tanks and some center

tanks) already have a low exposure to flammable conditions. Reducing flammability in

all fuel tanks to the level of the wing tanks on most airplanes, was seen as a

worthwhile goal. A variety of possible means to achieve this goal were evaluated for

technical and economic merits.
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The following conclusions were reached:

• Techniques to reduce or eliminate heat input to the tanks from nearby heat

sources were evaluated. Of these techniques, directed ventilation and

relocation of the significant heat sources reduce the exposure to an

acceptable level. However, relocation is only feasible for new airplane

designs. Directed ventilation for in service aircraft is estimated to have an

overall cost for a ten-year period of $3.5 billion.

• To reach the goal by changing fuel properties, a minimum flash point

specification of 140oF would be required. A change of this magnitude falls

outside of the current experience base and may require engine re-design/requalification. The overall fuel manufacturing cost increase for a ten-year

period is estimated at $15 billion in the USA and $60 billion for the rest of

the world and could result in a significant shortfall of jet fuel.

• Techniques such as on board fuel tank inerting or installation of foam in the

tanks would also achieve the goal, but at a cost estimated to be at least $20

billion over the next ten years and would be very difficult to retrofit in

current airplanes. Ground inerting, wherein specific tanks are made inert

prior to flight, at specific airports, is an option that needs future study to

determine; (a) the logistical costs of such a system and, (b) if retrofit

installation of the distribution system internal to the airplane could be

achieved in a cost effective manner.

• The Working Group considered several concepts that were determined to

be insufficiently advanced technically at this time, for transport airplane fuel

tank use. These included ullage sweeping and explosion suppression

systems.

An initial estimate provided by the FAA for the cost of future events is $2 billion over

the next ten years, if no changes are made in the fleet. The flammability reduction

techniques studied by the group have an economic impact greater than this, and

therefore careful consideration must be given to determine which avenue to pursue.

The first chart below depicts the relative costs and flammability exposure benefits of

various options studied. The fuel tank inspections, the service bulletins for wiring

improvements, and the anticipated SFAR for ignition sources (which the FAA is

studying independently of this effort) should reduce the hazard from ignition to a level

equivalent to a 6% flammability exposure. The estimated cost for the anticipated

SFAR is between $1-2 billion. This is depicted on the chart as a cross to differentiate

it from the options studied by the Working Group.
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The second chart below depicts the impact on the fuel tank explosion accident

frequency predicted for fuel system enhancements in flammability reduction and in

ignition source mitigation.
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0

5

10

15

20

25

30

35

40

0.0 5.0 10.0 15.0 20.0 25.0

120°F Fuel (Rest of World)

120 °F Fuel (US)

Directed

Ventilation

Insulation or

Redistribute Fuel

On-board Inerting

Fuel Tank Flammability Cost Benefit

Wing Tank

Cost of Accidents Over Next 10

Years

Without Improvements (Source FAA) Ground

Inerting

140° F Fuel (Rest of World)

$ 60 billion

Foam

140° F Fuel (US)

Percent Flammability Exposure (%)

Cost (billions

US Dollars)

Equivalent Effect

of SFAR
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0

10

20

30

40

50

60

0 5 10 15 20 25 30 35

CWT Exposure

Today

CWT Exposure

with SFAR

Flammability

 Reduction (<7%)

Flammability Reduction (<7%)

with SFAR

Inerting

or Foam

Effect of Fuel Tank Enhancements

Decreasing Concern

(Improvements)

Increasing Concern

Mean Time

between Accidents

(Years)

Percent Exposure (%) Note: Assumes a 4.3%

annual
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The Working Group evaluated potential regulatory actions and concluded that the

most effective action would be a revision of FAR 25.981 to address both ignition

source prevention and flammable fuel-air mixture exposure in a single regulation,

consolidating the major aspects of preventing tank explosions into one rule.

Recommendations

The ARAC Working Group recommends that the FAA/JAA pursue a cost effective

approach to enhance fuel tank safety.

The following specific recommendations are made:

1. Adopt the proposed new regulatory action on new aircraft designs.

2. Continue to investigate means to achieve a cost-effective reduction in flammability

exposure for the in-service fleet and newly manufactured aircraft.

3. Pursue the studies associated with directed ventilation and ground-based inerting

systems to improve their cost effectiveness.

4. If a practical means of achieving a cost effective reduction in flammability

exposure can be found for the in service fleet, either at the level specified in the

rule or at some intermediate level (recommendations 2 and 3 above), consider

application of that solution, in combination with other actions (e.g. SFAR).

5. If a practical means of achieving a cost effective reduction in flammability

exposure can be found for newly manufactured aircraft, either at the level specified

in the rule or at some intermediate level (recommendations 2 and 3 above),

consider application of that solution, in combination with other actions (e.g.

SFAR).
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Table of Contents

Executive Summary

Table of Contents

Chapter 1 General Considerations and Proposed Rule

1.1 Introduction

1.1.1 Background

1.1.2 Scope

1.1.3 Charter of the ARAC Fuel Tank Harmonization Working Group

1.1.4 Terms of Reference

1.2 Development of the ARAC FTHWG

1.2.1 FTHWG Organization

1.2.2 Charter and Deliverable of Each Task Group

1.2.3 Time Schedule

1.3 Standards Applied

1.3.1 Assumptions Made

1.4 Service History/Review of Past Accidents

1.5 Safety/Risk Assessment Methodology

1.5.1 Thermal Analysis

1.5.2 Exposure Analysis

1.5.3 Safety/Risk Assessment Methodology Conclusions

1.6 Proposed Rule

1.6.1 Methodology

1.6.2 Proposed Rule

1.6.3 Discussion on the Intent of the Proposed Requirement

1.6.4 Proposed Advisory Material

Chapter 2 Possible Compliance Methods

2.1 Introduction

2.2 Explosion Suppression

2.3 Reticulating Foam and Expanded Metal Products

2.4 Inerting

2.5 Fuel Vapor Reduction

2.5.1 Summary of impacts and applicability of the five methods evaluated

2.5.2 Summary of the effects of changing the fuel flashpoint, ground inerting and

combinations of different modifications

2.6 Modified Fuel Properties
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Chapter 3 Conclusions and Recommendations

3.1 Overall Conclusions

3.2 Recommendation

Attachments

1) Terms of Reference (TOR)

2) Organizational Chart

3) Task Group 1 – Service History/Fuel Tank Safety Level Assessment Final Report

4) Task Group 2 – Explosion Suppression Final Report

5) Task Group 3 – Fuel Tank Inerting Final Report

6) Task Group 4 – Foam Final Report

7) Task Group 5 – Fuel Vapor Reduction Final Report

8) Task Group 6/7 – Fuel Properties and Its Effects on Aircraft and Infrastructure Final

Report

9) Task Group 8 – Evaluation Standards and Proposed Regulatory Action Advisory Group

Final Report
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CHAPTER 1 GENERAL CONSIDERATIONS AND PROPOSED RULE

1.1 Introduction

1.1.1 Background

On July 17, 1996 TWA Flight 800, a Boeing model 747-131, exploded in flight shortly

after takeoff from Kennedy International Airport in New York. The accident

investigation led by the National Transportation Safety Board (NTSB) has not, as of

this date, determined the primary cause for the accident. Evidence gathered from the

accident site indicates that the center wing tank exploded, but an ignition source has

not been identified.

The NTSB sent four recommendations for regulatory changes to the Federal Aviation

Administration (FAA) on December 13, 1996. The NTSB had recommended that the

FAA require the development and implementation of design or operational changes

intended to eliminate, significantly reduce or control explosive fuel-air mixtures in fuel

tanks of transport category airplanes.

On April 3, 1997, the FAA issued a public notice soliciting comment on the feasibility

of implementing the NTSB recommendations. To support this request, airplane

manufacturers and airline operators initiated a comprehensive review of fuel system

design and operational practices.

Their report, issued July 30, 1997, concluded that the overall level of safety and

reliability of commercial airplane fuel systems was very high and any changes must be

carefully studied so that additional risks are not introduced. Net safety benefits must

be documented.

The industry further recommended that an international fuel tank group be established

to develop aircraft inspection programs to verify the integrity of wiring and grounding

straps, the condition of fuel pumps, fuel lines and fittings and the electrical bonding of

all equipment, to verify the design and assure that no ignition sources could exist in

fuel tanks.

Subsequent to this recommendation, airlines and airframe manufacturers initiated a

joint program to examine the condition of aircraft fuel tank wiring and bonding. This

program is called Aircraft Fuel System Safety Program (AFSSP) and the group plans

to issue a final report by the year 2000. The FAA participates in the leadership of the

AFSSP.

Late in 1997, the FAA announced the decision to develop a Special Federal Aviation

Regulation (SFAR) with the purpose of reducing the risk of ignition sources in fuel

tanks through design reviews and improved maintenance programs.
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In December 1997, the FAA/JAA announced the decision to initiate the Aviation

Rulemaking Advisory Committee (ARAC) Fuel Tank Harmonization Working Group

(FTHWG).

1.1.2 Scope

The historical approach to fuel system safety has been to control the risk of ignition

sources. All current regulation and commercial aircraft design is based upon this

philosophy. The ARAC FTHWG was tasked to recommend new rulemaking to

eliminate or significantly reduce the risk of exposure to flammable fuel-air mixtures in

fuel tanks.

1.1.3 Charter of the ARAC Fuel Tank Harmonization Working Group

The charter of the ARAC Fuel Tank Harmonization Working Group was:

1. To analyze:

• The history of the world transport aircraft fleet

• The safety status of the existing fleet

• Various means of reducing exposure to flammable fuel vapors

• Means to eliminate the resultant hazard if ignition does occur

2. To recommend regulatory text for new rulemaking aiming at controlling

flammability of fuel vapors in fuel tanks.

3. To assess the cost benefit of those means.

4. To assess the effect of the new rule on other sections of the industry.

5. To follow the rules for ARAC harmonization working groups.

6. To issue a final report within six months after publication of the Terms of

Reference (TOR).

1.1.4 Terms of Reference

The National Transportation Safety Board has concluded from the accident

investigation that an explosive fuel-air mixture existed in the center wing tank of TWA

Flight 800.

The FAA has identified 10 transport airplane hull loss events since 1959, which

involved fuel tank explosions. The investigation of TWA Flight 800 and the number of

fuel tank explosions which have occurred in service has led the FAA to question the

adequacy of transport airplane certification requirements relative to fuel tank design,

specifically with respect to environmental considerations and the adequacy of steps to
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minimize the hazard due to potential ignition sources, both in initial design and over

the life of the airplanes.

The FAA further believes that one of the approaches to improve fuel tank explosion

safety is the prevention or reduction of the occurrence of a flammable fuel-air mixture

in the tanks through some means of inerting, cooling/insulation, modified fuel

properties, installation of foam or fire suppression systems.

The task for the ARAC FTHWG was to prepare a report to the FAA/JAA that

provides specific recommendations and proposed regulatory text, that will eliminate or

significantly reduce the hazards associated with explosive vapors in transport category

airplane fuel tanks. Proposed regulatory text should ensure that new type designs, inproduction airplanes and the existing fleet of transport airplanes are designed and

operated so that during normal operation the presence of an explosive fuel-air mixture

in all fuel tanks is eliminated, significantly reduced or controlled to the extent that

there could not be a catastrophic event.

The report should include the following:

1. An analysis of the threat of a fuel tank explosion due to internal and

external tank ignition sources.

2. An analysis of various means of reducing or eliminating exposure to

operation of transport airplane fuel tanks with explosive fuel-air mixtures

or eliminating the resultant hazard if ignition does occur.

3. An analysis of the cost/benefit of modified fuel properties that reduce

exposure to explosive vapors within fuel tanks. Factors that may enhance

the benefits of modified fuels, such as cooling provisions incorporated to

reduce fuel tank temperatures, should be considered and cost information

for the various options should be developed.

4. Review comments to the April 3, 1997 Federal Register Notice such that

validated cost benefit data of a certifiable system is provided for the various

options.

5. Recommend objective regulatory actions that will eliminate, significantly

reduce or control the hazards associated with explosive fuel-air mixtures in

all transport airplane fuel tanks.

In addition to this task, the ARAC FTHWG should support the FAA/JAA in

evaluation of application of the proposed regulation to the various types of transport

airplanes and any impact on small businesses.

The activity was tasked for a 6-month time limit to complete the tasks.
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1.2 Development of the ARAC FTHWG

A public notice was issued in the Federal Register by the FAA on January 23, 1998

surveying industry and regulatory agencies for potential members for this Working

Group. Over 75 responses were received. Of those responses, over 45 Task Group

members were selected to become part of the FTHWG.

Members were selected based on background, expertise, and affiliation with a variety

of industry and regulatory groups. The FAA/JAA wanted to ensure that the

regulatory recommendations were developed by a broad-based group of stakeholders

who would be impacted by these changes. The FAA/JAA also wanted to access the

wide-ranging expertise that industry brings to this subject. ARAC operating

procedures were used throughout the process.

The 6-month timeframe specified by the FAA/JAA to complete this analysis was very

aggressive and unprecedented. Members selected for the FTHWG had to be available

on a nearly full-time basis for the 6-month period.

Due to the extensive amount of work currently taking place throughout industry in

harmonizing FAA and JAA regulations, the FAA/JAA also tasked the FTHWG with

ensuring that the regulatory recommendations developed were the product of a

consensus of the FAA, JAA and industry members.

The FTHWG was co-chaired by representatives of Aerospace Industries Association

(AIA) and The European Association of Aerospace Industries (AECMA) and made up

of representatives from:

Air Transport Association (ATA)

Air Line Pilots Association (ALPA)

International Air Transport Association (IATA)

Federal Aviation Administration (FAA)

Joint Aviation Authorities (JAA)

General Aviation Manufacturers Association (GAMA)

American Petroleum Institute (API)

1.2.1 FTHWG Organization

The members selected to participate in this project were divided into seven Task

Groups. Due to the short time frame of the project, several assignments had to take

place concurrently. Each assignment was given to a Task Group, with the entire

project being overseen by the nine-member FTHWG. An ‘Organization Chart’ of this

arrangement is attached. Much care was taken to balance the Working Group
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membership so that it represented all aspects of industry and regulatory agencies. Care

was also taken to balance each individual Task Group.

1.2.2 Charter and Deliverable of Each Task Group

Several tasks were undertaken simultaneously at the inception of the FTHWG. These

tasks fell into five main categories:

1) A review of service history;

2) A thermal analysis to quantify the current fleet exposure to flammable fuel-air

mixtures;

3) A detailed analysis of means to reduce exposure to flammable fuel-air mixtures

(such as fuel property changes, fuel tank inerting, ullage sweeping, ullage

washing, temperature control);

4) A detailed cost/benefit analysis of means to suppress explosions (such as

foam);

5) A set of proposed regulatory material.

Task Group charters and objectives are summarized below.

Task Group 1: Service History/Fuel Tank Safety Level Assessment

Prepare a detailed analysis of previous tank explosion events. Carry out a flammability

review of the current range of fuel system designs and tank configurations. Develop a

safety analysis tool to evaluate the safety impacts of any proposed (design) changes.

Task Group 2: Explosion Suppression

Research the industry for existing technologies and systems specifically designed to

actively monitor, detect, react to and suppress an explosion event before the event can

produce catastrophic results.

Task Group 3: Fuel Tank Inerting

Provide a feasibility analysis of fuel tank inerting systems. Focus on reducing or

eliminating exposure to explosive mixtures for transport airplane operations. Prepare a

cost/benefit analysis.

Task Group 4: Foam

Provide a feasibility analysis of foam systems. Also included is an analysis of expanded

metal products. Prepare a cost/benefit analysis.
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Task Group 5: Fuel Vapor Reduction

Quantify the exposure of fuel tanks to flammable vapor. Analyze means to reduce that

exposure. Prepare a cost/benefit analysis for each of the means.

Task Group 6/7: Fuel Properties and Its Effects on Aircraft and Infrastructure

Assess the feasibility of using jet fuel with a higher flash point in the transport airplane

fleet as a means of reducing exposure of the fleet to explosive fuel-air mixture. Include an

assessment of the impact of modified fuel properties on both the infrastructure and the

aircraft and its operations. Include a cost/benefit analysis.

Task Group 8: Evaluation Standards and Proposed Regulatory Action Advisory Group

Provide a common set of definitions to the other Task Groups so there is consistency in

the data used by all groups. Define a proposed regulatory action.

1.2.3 Time Schedule

A milestone schedule was developed at the first FTHWG meeting in February 1998.

The FTHWG agreed to meet together for a two-day period each month. Task Groups

were instructed to meet as often as necessary. The final report was due 23 July 1998.

1.3 Standards Applied

A common set of standards was necessary to achieve consistent results in performing

cost benefit studies. To achieve this consistency, Task Group 8 was chartered to

provide a common set of definitions to the other Task Groups.

1.3.1 Assumptions Made

A spreadsheet was developed to provide a common source of data to be used by the

task groups in order to ensure that the potential methods were evaluated using

consistent data and assumptions. Data were included in the spreadsheet for six generic

airplane types: small, medium and large transports, regional turbofans, regional

turboprops and business jets. The data included summaries for each airplane type,

such as fleet size, weights, fuel volumes and flight distributions. Mission profile data

such as weight, altitude, Mach number, fuel remaining in each tank and body angle as

a function of time was included for each generic airplane type. Temperature profiles

ranging from cold to extremely hot were also included in the mission profiles.

Performance trades and cost trades were also included to allow the consistent

calculation of performance and cost impacts. Details of the standards and assumptions

can be found in the Task Group 8 report.
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1.4 Service History/ Review of Past Accidents

The service history of the transport airplane fleet (including turbofan and turboprop

airplanes) over the last forty years was examined, and information regarding known

instances of fuel tank explosion (other than those caused by post-impact crash events)

was assembled. The starting point was the table of events contained in the FAA

Notice on Fuel Tank Ignition Prevention Measures published in the Federal Register

on April 3, 1997. The data sources used were accident and incident reports provided

by investigating organizations, regulatory authorities, and original equipment

manufacturers’ safety-related databases. The level of details reported in the early

events was sometimes limited depending on the event location and the type of event

(whether it involved an internal or external ignition source).

The attached service history report by Task Group 1 contains a detailed description of

each event and the findings of the investigating authority, followed by a description of

the mitigating actions taken subsequent to the event. The events have been separated

into operational events and refueling and ground maintenance events. They are

grouped by cause (lightning, engine separation, refueling, maintenance, etc.), and are

then categorized by operational phase, ignition source, type of fuel tank involved, and

fuel type. The mitigating actions taken after each event are summarized and any

recurring events are identified.

From the analysis, certain patterns emerge:

• Of the 16 fuel tank events examined, 8 involved wing tanks, 8 involved center

or fuselage tanks;

• There were 9 operational events and 7 refueling and ground maintenance

events.

• There were only 2 explosions due to lightning strike, with 396 million flight

hours accumulated since the last event in 1976;

• In the wing tank events, 5 out of 8 involved the use of wide-cut fuel (JP-4/Jet

B);

• In the wing tank events, 5 out of 8 occurred in-flight;

• All the wing tank events involved external ignition sources - there were no

known wing tank explosions due to internal ignition sources in the 40 years of

commercial jet aviation history;

• All the center tank events involved the use of Jet A/Jet A-1 fuel;

• In the center tank events, 6 out of 8 occurred on the ground;
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The data suggests that there is a difference in the respective safety levels between wing

tanks and center tanks.

All the wing tank events have been due to known, external ignition sources (lightning

strikes, over-wing fire, refueling, maintenance error). There were no known internal

ignition sources in 520 million hours of commercial transport fleet operation that

resulted in a tank explosion. Corrective actions to prevent recurrence of these wing

tank events have been in place for many years, and have been demonstrated to be

effective.

However, in the two most recent center tank events the ignition sources have not yet

been identified. While corrective actions to identify and eliminate potential ignition

sources are being put in place, the investigation of flammability reduction is warranted

since the efficacy of these actions has yet to be proven.

Over the years, center tanks have accumulated considerably fewer operating hours

than wing tanks (for example, a typical twin-engine transport has two wing tanks and

one center tank, and therefore accumulates wing tank hours at twice the rate of center

tank hours). Since the equipment in wing and center tanks is very similar, i.e. there are

similar types and numbers of potential ignition sources, one might expect there to be

significantly fewer center tank events than wing tank events. Actually, the numbers of

events are equal. This suggests that these tanks have not yet reached the safety level

attained by wing tanks, and that action to further reduce the flammability levels in

center tanks should be considered.

It might be argued that the reason for this disparity is that components in the wing

tanks are more often submerged than those in the center tanks, which empty prior to

wing tanks. However, this may be an over-simplification. There are several pieces of

electrical equipment inside wing tanks, which routinely operate in the vapor space. The

disparity may be the result of the center wing tanks being significantly more flammable

than wing tanks. Therefore, altering the flammability level in center tanks equivalent to

wing tank levels appears to be a worthwhile target.

The absence of explosions in wing tanks due to lightning strike supports this view.

Lightning strikes frequently occur. On average, every aircraft in the world fleet

experiences one strike per year. Yet, the data shows that there are only two explosions

due to lightning strike in a database spanning 40 years, with the last event occurring 22

years ago. However, both involved the use of wide-cut fuel (JP-4), which has a much

higher volatility than kerosene fuel (Jet A/A-1) and whose flammability envelope

coincides much more closely with the normal flight ranges of altitude and ambient

temperature. The phasing-out of wide-cut fuel from commercial airline use means that

for a large proportion of the flight envelope the wing tank ullage is non-flammable.

In the last 20 years (when Jet A/A-1 has been the predominant fuel), there have been

five fuel tank explosion events involving center/fuselage tanks, and two wing tank

events. The continuing incidence of center tank explosions (all of which involved Jet
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A/A-1 fuel) indicates that these tanks have not yet reached the safety level attained by

wing tanks, and that action to further reduce the flammability levels in center tanks

should be considered.

This study identified and analyzed 16 known instances of fuel tank explosions (other

than those following impact with the ground) over the past 40 years of transport

aircraft operations worldwide. The following conclusions have been drawn:

• There is a close relationship between the incidence of explosions in wing tanks

and the use of wide-cut fuel.

• Wing tanks operating with Jet A/A-1 fuel have demonstrated an acceptable

safety record.

• Center tank and fuselage mounted tanks have also shown a low probability of

explosions, but there is some evidence that they are more vulnerable to

explosion in the presence of ignition sources.

• Apart from the two most recent events, which involved Center Wing Tank

with thermal inputs to the tanks, (1990/Manila & 1996/New York), the causes

of all the other events have been addressed by actions designed to prevent or

minimize their recurrence.

• The Safety Level Performance of wing tanks has been identified as a target for

the technologies applied to center wing tanks and their safety level

performance.

1.5 Safety/Risk Assessment Methodology

A safety/risk assessment methodology was developed to quantify the current fleet

exposure of fuel tanks to flammable fuel vapors, and then to predict the reduction in

exposure achievable by implementation of various methods. The additional risks that

may be introduced as a result of implementation of a method must be taken into

account in the net safety assessment. This methodology was used as the benefit half of

the cost/benefit analysis.

1.5.1 Thermal Analysis

To define the current fleet of fuel tanks, the methodology was to study different fuel

tank configurations on airplanes over a wide range of size. Tank configurations

analyzed included several wing tanks and several center tanks, some with and some

without adjacent heat sources. Representative airplanes from each of the generic size

categories were chosen for the analysis (large, medium, and small transports, regional

jets and business jets.)
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To define the exposure to flammable fuel vapors, the methodology was to quantify the

amount of time that the fuel temperature is above the flash point of the fuel over the

mission profile. The analysis therefore has three main variables; fuel temperature,

mission profile, and flash point.

Fuel temperature – In order to quantify the fuel temperature for each

fuel tank configuration, thermal analysis of the fuel tank was required,

including the affects of adjacent heat sources. Because airplanes

operate in a wide range of environments, thermal analysis over a wide

range of ambient temperatures was required. Ground and in-flight

atmospheric data was used to define the range of ambient temperatures

and flight route/frequency data was used to define the probability of a

flight encountering a particular ambient condition. From this

distribution, representative ambient temperature profiles were chosen

as the inputs to the thermal analysis to produce a range of fuel

temperature profiles with a defined distribution.

Mission profile – Airplanes operate over a wide range of missions. For

each airplane, flight range/frequency data was used to define the

distribution of mission lengths. Three mission profiles were chosen to

be representative of typical, short, medium and long flights.

Mission Length

Medium

Missions Long

Missions

Short

Missions

Ambient Temperature

Thermal

Analysis

Fuel Temperature
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Flash point - To define the flash point of the fuel, the initial assumption

was to use the specification limit of 100°F. However, as the objective

was to define the exposure of the current fleet of airplanes as they

actually operate, it was decided to increase the accuracy of the analysis

by using the flash point of the fuel that is loaded onto the airplane.

Task Group 6/7 collected data on the current distribution of flash

points delivered worldwide and assigned probabilities of a specific

mission being fuelled with a fuel at a specific flash point.

1.5.2 Exposure Analysis

To quantify the fleet exposure, a statistical analysis approach was applied to a

statistically significant number (10,000) of randomly selected flights. The flights were

then selected to be representative of the fleet using the defined distributions of the

three variables. For example, flight one may be a short mission on a cold day with an

average flash point fuel, and flight two may be a long mission on an average day with a

low flash point fuel, and on and on until 10,000 flights have been defined in this

manner. For every one of the 10,000 flights, the time that the fuel temperature was

above the flash points was calculated. The results of the exposure analysis are best

displayed in the form of a histogram like the example shown below.

Fuel Flash Point
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Averaging the results for all 10,000 flights provides an average percentage of the flight

time that any particular flight could be expected to be exposed to a fuel temperature

above the fuel flash point. These fleet average exposure results are given for each

airplane size and tank configuration in the table below.

Exposure Analysis Results

Wing Tanks Center Tanks

WITHOUT

adjacent heat

sources

WITHOUT

adjacent heat

sources

WITH

adjacent

heat sources

large small regional

turbofan

bizjet small regional

turbofan

large small

5% 5% 30%

Once the current fleet exposures to fuel tanks with flammable vapors are calculated,

the same method of thermal analysis / exposure analysis is used to systematically study

methods to reduce the exposure in fuel tanks.

More information on the exposure analysis and thermal analysis can be found in the

Task Group 5 report in sections 5.0 and 15.0. Results of the exposure analysis for

each of the considered methods can be found in section 2.5 of this report, with more

information in the Task Group 5 report.

1.5.3 Safety/Risk Assessment Methodology Conclusions

This safety/risk assessment methodology was developed to quantify the current fleet

exposure of fuel tanks to flammable fuel vapors. Quantifying the exposure is a very

complex task, so simplifying assumptions had to be made to complete the analysis in

the tight time frame available, such as the use of generic airplane fuel tank

configurations and typical flight profiles. To ensure confidence in the process, an

independent third party audit was conducted by members of the API. The auditors

agreed with the process as a valid method to quantify exposures. As discussed in the

proposed advisory circular (Task Group 8 report), a simpler method of exposure

analysis is currently under development.

1.6 Proposed Rule

The proposed rule was created to serve two purposes, firstly to provide a constant

standard for the various task groups to use to develop solutions and to develop

internally consistent comparisons, and secondly to provide the draft of a proposed rule

to the FAA/JAA if the cost benefit analyses showed such a rule to be of overall

benefit.
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1.6.1 Methodology

The intent of the proposed rule is to achieve a level of safety that would reduce the

probability of another fuel tank explosion event to a low enough level that one would

not be expected to occur in the life of a given airplane type. The proposed rule was

developed using the history of the fleet from Task Group 1 in conjunction with the

analysis of Task Group 5 of the current flammability levels in the fleet today.

This approach was thus to look at the history for factors in explosion events, and then

to look at the flammability modeling to see if there were matching factors. The other

driver in looking at the proposed rule was to recognize that ignition prevention has

been, and will continue to be, the primary protection technique for fuel system

explosion prevention.

The group recognized that the FAA was pursuing a plan to address ignition source

control through the SFAR process, and that the current rules, while being adequate at

a high level, may not be specific enough at a detail level. To address all of these factors

the group concluded that the proposed rule should address explosion prevention in one

rule, with ignition source control being the first element and flammability control being

the second.

The study concluded that fuel tank explosions were the result of unique circumstances

at a single point in time, rather than circumstances that generate a continuous or

intermittent ignition condition. The reasoning for this conclusion is that the

flammability exposure of certain tanks was high (30% of fleet operating time) and

therefore if circumstances created long duration ignition conditions, we would expect

a far higher number of events than the fleet history shows. Based on this, it was

concluded that the presence of an ignition source in any one tank was a very unlikely

random event and the recommended way to further reduce the probability of an

explosion is to limit the time during which the tank is in a flammable condition. It was

concluded that total elimination of flammability is not required in as much as wing

tanks operating with relatively low levels of flammability exposure have an excellent

safety record.

In addressing the flammability section of the proposed rule, the group considered that

total elimination of flammability was not required in as much as wing tanks operating

with relatively low levels of flammability exposure have an excellent safety record.

With this in mind, the group examined the flammability exposure of various tanks on a

wide range of airplane types to determine how to define flammability exposure and

how to select a suitable target to use in the rule. The Working Group determined from

examination of various airplanes types that the exposure of wing tanks, without

additional heat input from sources nearby, was below 6% of fleet operating time, while

tanks exposed to heat input were flammable for up to 30% of the fleet operating time.

The fleet history suggested that wing tanks with low flammability exposure had an
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excellent record, and thus a flammability limit that matched the wing tanks of most

airplanes was selected for use in the proposed rule.

As noted above, the proposed rule was used to define a set of requirements to size and

cost the various systems to satisfy the requirements. The cost benefit analysis provides

the data to assess the reasonableness of adopting this rule versus focusing on ignition

prevention as the means to reduce events to an acceptable level.

1.6.2 Proposed Rule

In order to enhance fuel system safety, the group recommends to the FAA/JAA the

following action:

Create a revised paragraph FAR 25.981 to address fuel tank protection from airplane

created threats that could prevent continued safe flight and landing. The proposed

revision is as follows:

Section 25.981 Fuel Tank Ignition Prevention

 The fuel system must be designed and

arranged to prevent the ignition of fuel vapor

within the tanks, or mitigate the effects of

such an ignition by addressing:

(a) Ignition Sources

(a)1. Place the current 25.981 requirement

here

(a)2. Additional requirements in ignition source

mitigation as defined by the FAA would be

in section (a)2, (a)3, etc. as defined by the

SFAR effort underway

(b) Flammable Vapors

Limiting the development of flammable

conditions in the fuel tanks, based on the

intended fuel types, to less than 7% of the

expected fleet operational time, or

Providing means to mitigate the effects of an

ignition of fuel vapors within the fuel tanks

such that any damage caused by an ignition

will not prevent continued safe flight and

landing.
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1.6.3 Discussion on the Intent of the Proposed Requirement

The proposed regulatory action provides a single regulation to address ignition

prevention, thereby avoiding having several paragraphs which must be linked and

interpreted in conjunction with each other. It provides the industry with a requirement

that addresses all aspects of fuel tank ignition prevention/mitigation, which can be

treated as a comprehensive requirement and addressed as one issue. The existing

requirements set forth in sections 25.901, 25.954 and 25.981 are intended to preclude

ignition sources from being present in airplane fuel tanks. As proposed, Paragraph (a)

maintains these requirements, which have been, are, and should continue to be, the

essential primary elements in fuel tank safety. Paragraph (b) provides a requirement to

address flammability mitigation as a new layer of protection to the fuel system. The

intent of the combined regulation is to prevent an applicant relying solely on ignition

prevention or on flammability reduction as the means to protect the fuel system from

ignition events.

1.6.4 Proposed Advisory Material

A proposed AC/ACJ 25.981 (b) is included in the Task Group 8 Report. This ACJ sets

forth an acceptable method of compliance with the requirements of FAR/JAR

25.981(b). The guidance provided within this AC is harmonized with the FAA and

JAA and is intended to provide a method of compliance that has been found

acceptable.
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CHAPTER 2 POSSIBLE COMPLIANCE METHODS

2.1 Introduction

This chapter summarises the findings of the Task Groups that investigated possible

means to comply with the proposed rule.

Where possible, cost to the industry of each means is given.

Detailed reports of each Task Group’s work are attached to this report.

2.2 Explosion Suppression

Task Group 2 has performed a search for reference material and documents

concerning systems that have been specifically designed to suppress or extinguish an

explosion within a fuel tank. This search quickly revealed that a great amount of

research had been accomplished in this arena concerning military operations and the

need to protect combat aircraft from external threats where fuel ignition could result.

From actual live-firing tests and system performance bench tests, a number of systems

have demonstrated positive results in providing fuel tank and dry bay protection from

fuel vapor explosions. The applicable technologies center around four separate

methods of dispersing the suppressant:

TM Inert Gas Generators

TM Gas Generator driven Agent Dispersal

TM Explosive Expulsion of Low Pressure Agent

TM Explosive Release of High Pressure Agent

Four companies were contacted, and provided information pertinent to the above

suppression methods.

From the review of the data presented by these companies, it is evident that the

technology exists and is effective in suppressing the pressure effects of an explosion

before those effects can become hazardous to the tank enclosure / structure. However,

this technology is not yet fully mature and a significant amount of development is still

required to understand to the specific requirements of fuel tank wet-bay protection.

No cost information is provided in this report due to the lack of maturity for fuel tank

application.
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2.3 Reticulating Foam and Expanded Metal Products

This report provides information on two types of materials available for installation

inside aircraft fuel tanks to reduce the risks of aircraft hull losses in case of explosions:

• Reticulated polyether foam.

This type of material has been used effectively on US military aircraft such as

P-3 and C-130.

• Expanded metal products.

This type of material is not widely used on transport aircraft.

Both have more than one application, and both will require FAA/JAA certification.

Some will require extensive qualification tests. When installed inside fuel tanks both

materials create their own disadvantages such as weight increase, fuel volume loss,

increased pack bay temperatures, structural integrity degradation, Foreign Object

Debris (FOD) and maintenance difficulties. Costs associated with using one alternative

of each product have been estimated for generic center tanks, with adjacent heat

sources. These estimates include total cost, i.e., designs, installations, and operations.

It is estimated that over a ten-year period it would cost the industry over 22 billion

dollars to use expanded metal products and over 25 billion dollars to use foam.

The following two tables show the cost breakdowns in $US for the two classes of

aircraft. Cost estimate totals are:

Per Aircraft Cost, In service aircraft, (Center Wing Tank only)

Aircraft Size Foam

Nonrecurring

Foam

Annual

Exp Metal

Nonrecurring

Exp Metal

Annual

Large $390,740 $1,584,121 $848,273 $1,329,017

Medium $187,427 $653,497 $366,057 $538,951

Small $64,161 $120,448 $112,605 $88,992

Per Aircraft Cost, Production Aircraft (Center Wing Tank only)

Aircraft Size Foam

Nonrecurring

Foam

Annual

Exp Metal

Nonrecurring

Exp Metal

Annual

Large $353,884 $1,584,121 $811,416 $1,329,017

Medium $166,334 $653,497 $344,964 $538,951

Small $54,636 $120,448 $103,081 $88,992
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The findings from this Task Group have shown that foam or expanded metal products

can be used effectively to prevent structural failure of fuel tanks as a result of an

internal explosion. However, when installed, foam or expanded metal products will

reduce aircraft payload and available fuel volume. These reductions are the two most

important factors that could result in severe economic impact for operators along with

possible health and safety risks, requiring fire prevention, storage and handling of these

products in hangars.

2.4 Inerting

The Inerting Task Group studied the technologies offered by the respondents to the

FAA’s Request for Information. Several technologies for providing inert gas were

reviewed including carbon dioxide in gaseous form and as dry ice, nitrogen in gaseous

and liquid form, and exhaust gas.

The group analyzed the impacts of carrying an on-board inerting system versus a

ground-based system. In addition, the group studied the cost and benefit of inerting

the center wing tank only versus inerting all of the aircraft’s fuel tanks. Finally, two

methods of purging oxygen from the tank were reviewed i.e. “scrubbing” the fuel and

“washing” the ullage space above the fuel.

A ground-based system that reduces flammability exposure below the 7% target

provides the potential for the least costly (non-recurring cost) inerting system on the

aircraft. However, it requires a substantial investment in ground equipment to supply

inerting gas, plus the recurring costs of the inerting gas and operation of the

equipment. Ground-based ullage washing is effective when considered in combination

with the normal changes to fuel temperature during a flight. On average, the exposure

to a flammable, non-inert ullage is approximately 1%.

Scrubbing fuel at the airport fuel farm, or on the aircraft during refueling, is the least

effective form of tank inerting. The ullage is not inert during taxi, takeoff, and initial

climb until inert gas evolves from the fuel. As fuel is consumed from a fuel tank,

ambient air flows in to replace it and raises the oxygen concentration. The tank may

only be inert for the latter portion of climb and the beginning of cruise. This is highly

dependent on the initial fuel load. Clearly, this method provides little added protection

to today’s design. In addition, this method would provide no added protection for

near empty fuel tanks.

On-board systems could provide inert gas throughout the flight and offer zero

exposure to a flammable, non-inert ullage. There are several existing methods for

providing nitrogen on board an aircraft. It can be stored as a gas in bottles or as a

liquid in Dewar bottles, such as on the C-5. Either of these would require

replenishment at an airport, which adds to the cost of the airport infrastructure.

An alternative to storing gases or liquids, On-board Inert Gas Generating Systems

(OBIGGS) separate nitrogen from engine bleed air. Such systems exist on military
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aircraft today, notably the C-17 as well as some fighters and helicopters. All of these

systems extract a performance penalty from the aircraft. A new aircraft design offers

the best opportunity to minimize these penalties. Current production aircraft and the

retrofit fleet may incur redesign and operational penalties that make them

uneconomical to fly. Operational compromises will almost certainly be required.

None of the airplanes analyzed have enough engine bleed air available to supply these

systems.

Whichever type of inerting might be used, there are potential hazards to personnel.

Gaseous inerting agents present a suffocation hazard and liquid nitrogen presents the

additional hazard of freezing trauma to skin and eyes.

Several other on-board systems were reviewed. Exhaust gas from the jet’s engines

and auxiliary power unit (APU) was deemed infeasible primarily because the exhaust

contains too much oxygen. Carbon dioxide in gaseous and solid (dry ice) form was

also deemed infeasible. Except for nitrogen systems, none of the systems were mature

enough to be considered for installation on commercial aircraft. Nitrogen is the best

candidate at this time.

The following table provides a summary of the cost and benefit of each system.

Technology Exposure Cost over 10 Years (US Dollars)

On-board Liquid Nitrogen for All

Tanks

< 1% $35.7B

On-board Gaseous Nitrogen for All

Tanks

< 1% $33.9B

Air Separator Modules for All

Tanks

< 1% $37.3B

Air Separator Modules for the

Center Tank

< 1% $32.6B

Ground-based Ullage Washing with

natural Fuel Cooling for Center

Tank

1% $4B with gaseous nitrogen

$3B with liquid nitrogen

At this time, nitrogen appears to be the best inerting agent and there are several means

of providing it to the aircraft. Ground-based ullage washing in combination with the

drop in temperature within the tank reduces exposure to a flammable, non-inerted tank

to approximately 1%. This is the most cost effective solution studied, with the cost

over a 10 year period estimated at approximately $3 billion.

Present day aircraft do not have enough available engine bleed air, in most cases, to

supply an OBIGGS type system. However, OBIGGS systems could be designed into

future aircraft.
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If a full-time inerting system were required for current production aircraft or retrofit

airplanes then liquid or gaseous nitrogen storage could be placed on-board the

airplanes. These systems tend to be a little heavier than OBIGGS and require

additional airport infrastructure to support them. The overall cost for a 10 year period

is similar to OBIGGS.

2.5 Fuel Vapor Reduction

Task Group 5 analyzed the exposure of fuel tanks to flammable vapor and evaluated

methods to mitigate the exposure, considering the related impacts: safety, certification,

environment, airplane design, operations and cost. Analysis has also been performed to

assess the effects of ground inerting and changing the fuel flashpoint in mitigating the

exposure to flammable vapors (see reports from Task Group 6/7 and Task Group 3

for the impacts of these modifications). This analysis has been completed for generic

airplanes and therefore does not relate to any specific airplane design.

Thermal analysis has shown that all generic fuel tank designs have some exposure to

flammable fuel vapor.

• Tanks without adjacent heat sources, independent of location, (wing or

fuselage), have equivalent exposure of approximately 5%.

• Tanks with adjacent heat sources have exposure of approximately 30%.

Other factors affecting exposure are:

• Ambient temperature (of which control is not possible)

• Fuel loading (which is discussed further, see option 3)

• Altitude (which is not discussed within this report)

Thirteen methods of mitigating the effects of heat sources adjacent to fuel tanks have

been analyzed. Only one eliminates exposure to fuel vapors. This is achieved by

disabling the fuel tank and thus has severe operational consequences that can only be

evaluated for individual airlines operations, and thus no conclusion is provided within

this report.

Five options considered reduce the exposure to flammable fuel vapor, and have been

evaluated for the small, medium and large transport airplanes:

1. Insulate the heat source adjacent to fuel tanks

2. Ventilate the space between fuel tanks and adjacent heat sources

3. Redistribute mission fuel into fuel tanks adjacent to heat sources

4. Locate significant heat sources away from fuel tanks.

5. Sweep the ullage of empty fuel tanks.
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Options 2 and 4 have been shown to reduce the exposure of fuel tanks with adjacent

heat sources to a level similar to fuel tanks without adjacent heat sources. (Option 4 is

only applicable to new airplane designs).

Option 5 requires significant further research before a conclusion on its feasibility can

be reached.

Table 2.5.1 summarizes the effects and impact of the five options.

Table 2.5.1 Summary of impacts and applicability of the five methods evaluated

Centre Wing Tanks With Adjacent Heat Sources

Exposure to Flammable Vapours 30%

Fuel Tanks Without Adjacent Heat Sources

Exposure to Flammable Vapors 5 %

OPTION

IMPACT

1.

Insulate

Heat

Sources

2.

Ventilate

(Directed)

3.

Redistribute

(Fuel)

4.

Locate

Heat

Sources

5.

Sweep

Ullage

Estimated Exposure to

Flammable Vapors after

Modification

20% 5% 20% 5%

Not

quantified

New safety Concerns minor none medium none medium

Certification Impact minor minor minor none major

Environmental Impact none none none none yes

Airplane Impact minor medium minor major medium

Operational Impact minor minor major minor major

One Time Small

Fleet Costs Medium

($ Million) Large

160

50

100

500

60

300

4

2

3

160

50

100

2,000

650

1,200

Annual Fleet Small

Costs Medium

($ Million) Large

10

2

2

170

20

70

7

3

14

?

?

?

370

80

180

10 Year Fleet Costs

($ Million)

450 3,500 250 ? 10,000

Applicability most most most new designs most

In addition, the effects of ground inerting and changing the fuel flashpoint were

assessed. Either method could reduce the exposure of fuel tanks with adjacent heat

sources to a level similar to fuel tanks without adjacent heat sources.

Table 2.5.2 summarizes the effects on exposure of ground inerting, changing the

flashpoint, and some potential combinations of modifications. This is not an inclusive

list of all feasible combinations due to the time constraints involved in this project.
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Table 2.5.2 Summary of the effects of changing the fuel flashpoint, ground inerting and

combinations of different modifications.

Modification

Wing Tanks

Without heat

sources

Center Tanks

without heat

sources

Center Tanks

with heat

sources

Current Airplanes 5% 5% 30%

120°F Flashpoint Fuel

130°F Flashpoint Fuel

140°F Flashpoint Fuel

150°F Flashpoint Fuel

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

10 to 20%

5 to 10%

1 to 5%

1%

Ground Based Inerting

of Fuel Tanks

Not applicable < 1% 1%

Combinations of

Modifications

Ventilate (Directed)

and 120°F Flashpoint Fuel

Not applicable Not applicable < 1%

Insulate

and 120°F Flashpoint Fuel

Not applicable Not applicable 5%

Insulate

and 130°F Flashpoint Fuel

Not applicable Not applicable 1%

2.6 Modified Fuel Properties

The purpose of this Task Group report is to evaluate the availability, cost, and risk

associated with changing to a high flash point specification jet fuel for commercial

aviation.

The Fuels Properties Task Group was charged with assessing the feasibility of using

jet fuel with a higher flash point specification in the civil transport airplane fleet than

required by current Jet A/Jet A-1 specification, as a means of reducing the exposure of

the fleet to flammable/explosive tank vapors.

Raising the minimum flash point specification of jet fuel will result in a combination of

changes to other fuel properties, such as viscosity. The magnitude of change is

dependent on the magnitude of flash point increase. The engine and APU

manufacturers have no experience base for such a modified specification, and are

concerned about the risk and potential adverse impact on altitude relight and low

temperature operations (especially Extended Twin Operations, ETOPS). Mitigating

actions, including hardware modifications, fuel specification revisions, use of additives

and revised operational limits, have also been reviewed. Laboratory, rig and/or fullscale engine testing on reference fuels may be required to quantify the impacts

depending on the magnitude of change.
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Raising the minimum flash point specification could also significantly raise the

manufacturing cost and decrease the availability of the modified jet fuel. The reduced

availability could have a significant impact on jet fuel price. Again, the higher the flash

point, the more severe the effect.

The fuel impacts are most severe outside of the U.S. due to the differences in overseas

refinery configurations and product demand. Some countries indicated that a change

in flash point specification is not an option to which they would subscribe (Canada,

New Zealand, Australia, Japan, United Kingdom, Russia and the Commonwealth of

Independent States).

Conclusions of the group are:

An increase in the jet fuel flash point specification will result in shifts of fuel

properties. At some increase in the flash point specification, a high flash Jet-A

becomes a new fuel, never before used, with properties unlike any other fuel. The

predicted fuel specification changes will result in a combination of fuel properties that

can fall outside the current experience. The magnitude of property change and

potential introduction of new molecules increases with increasing flash point.

Higher flash points could result in significant shortfalls of jet fuel availability and could

require at least five years for industry to endeavor to meet jet fuel demand.

Estimated Refinery Shortfall For First 2 Years

Flash Point In US Outside US

120° F 5% 12%

150° F 20% 49%

The API survey results address jet fuel demand at 1998 levels. The survey does not

address long-term changes in jet fuel demand, which is projected to grow by 6-15%

more than other refined products by 2010. Environmentally driven reformulation of

other fuels, (e.g., toward “light” diesel) will further increase demand for the jet fuel

portion of the barrel. These pressures are likely to amplify the difficulties predicted for

the 1998 level.

Requirements for higher flash point jet fuels could result in United States refinery

production cost increasing 1.5-2.2 cents per gallon at 120 degrees and 6-7.5 cents per

gallon at 150 degrees (assuming 7% ROI). Based on current U.S. jet demand, this

translates into annual costs of $350-520 million at 120 degrees and $1.4-1.7 billion at

150 degrees. Outside the United States, requirements for higher flash point jet fuel

will result in refinery production cost increasing 3-15 cents per gallon at 120 degrees

and more than 20 cents per gallon at 150 degrees.
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Cost Increase

Flash Point Inside US Outside US

120° F 1.5 – 2.2 Cents/gallon

($350-520M Annually)

3-15 Cents/gallon

150° F 6 – 7.5 Cents/gallon

($1.4 – 1.7B Annually)

>20 Cents/gallon

The potential for increased production cost and decreased capacity could dramatically

impact the market price of jet fuel. Models have been used to calculate the increases in

price that could occur for various combinations of capacity reductions and price

elasticity. No substitutions for jet fuel were assumed to be available. Based on a price

elasticity of 0.2, the annual cost is $4 to $13B.
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CHAPTER 3 CONCLUSIONS AND RECOMMENDATIONS

3.1 Overall Conclusions

The study concluded that each fuel tank explosion analyzed was the result of unique

circumstances at a single point in time, rather than circumstances that generate a

continuous or intermittent ignition condition. The reasoning for this conclusion is that

the flammability exposure of certain tanks was high (30% of fleet operating time) and

therefore if circumstances created long duration ignition conditions, we would expect

a far higher number of events than the fleet history shows. Based on this, it was

concluded that the presence of an ignition source in any one tank was a very unlikely

random event and the recommended way to further reduce the probability of an

explosion is to limit the time during which the tank is in a flammable condition. It was

concluded that total elimination of flammability is not required in as much as wing

tanks operating with relatively low levels of flammability exposure have an excellent

safety record.

A maximum flammability exposure of 7% of expected fleet operational time was

selected for use in the proposed rule. This exposure approximates that of wing tanks

on most airplanes.

The proposed regulatory action provides the industry with a requirement that

addresses all aspects of fuel tank explosion prevention/mitigation, which can be treated

as a comprehensive requirement and addressed as one issue. The intent of the

combined regulation is to ensure an applicant addresses both ignition prevention and

flammability reduction to protect the fuel system.

A range of possible means to achieve this goal was evaluated for technical and

economic merits. The following conclusions were reached:

• Explosion suppression technology is not yet fully mature. A significant amount of

development is still required to refine the details to meet the specific requirements

for fuel tank protection;

• Foam or expanded metal products can be used effectively to prevent structural

failure of fuel tanks as a result of an ignition. However, foam or expanded metal

products will reduce aircraft payload and available fuel volume. These reductions

result in severe economic impact for the industry. There are also health and safety

risks associated with storage and handling of these products;

• Nitrogen appears to be the best inerting agent at the present time. Ground-based

ullage washing, in combination with the normal changes to fuel temperature during

a flight, reduces exposure to approximately 1%. This is the most cost-effective

inerting solution studied, with the cost over a 10-year period estimated at

approximately $3 billion.
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For on-board inert gas generating systems (OBIGGS), most in-service aircraft do

not have enough engine bleed air supply. However, future aircraft could be

designed to accommodate these systems. Liquid or gaseous nitrogen storage

inerting system could be adapted for in-service aircraft. These systems tend to be

heavier than OBIGGS and require additional airport infrastructure. The overall

cost for a ten-year period is similar to OBIGGS and estimated at approximately

$30 billion.

• For fuel vapor reduction, five of the options considered reduce the exposure to

flammable fuel vapor. These are:

• Insulate the heat source adjacent to fuel tanks;

• Ventilate the space between fuel tanks and adjacent heat sources;

• Redistribute mission fuel into fuel tanks adjacent to heat sources;

• Locate significant heat sources away from fuel tanks;

• Sweep the ullage of empty fuel tanks.

Only directed ventilation and relocation of the significant heat sources reduce the

exposure to an acceptable level. However, relocation is feasible only for new

airplane designs. Directed ventilation for in service aircraft is estimated to have an

overall cost for a ten-year period of $3.5 billion.

• To reach the goal by changing fuel properties, a minimum flash point specification

of 140oF would be required. A change of this magnitude falls outside of the current

experience base and may require engine re-design/re-qualification. The overall fuel

manufacturing cost increase for a ten year period is estimated at $15 billion in the

USA and $60 billion for the rest of the world and could result in a significant

shortfall of jet fuel.

Fuel tank explosions represent less than one percent of the accidents that occur in

commercial aviation. The FAA has provided an estimate of the cost of future events to

be $2 billion over the next ten years, if no fuel systems enhancements were made. The

flammability reduction techniques studied by the ARAC Working Group have an

economic impact far greater than this.

In addition, the FAA is conducting a thorough review of current design and

maintenance practices, which will act to improve the safety of fuel tanks by addressing

ignition source mitigation. The group concludes this approach will achieve a

significant enhancement in safety.
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3.2 Recommendation

The ARAC Working Group recommends that the FAA/JAA pursue a cost effective

approach to enhance fuel tank safety.

The following specific recommendations are made:

1. Adopt the proposed new regulatory action on new aircraft designs.

2. Continue to investigate means to achieve a cost-effective reduction in flammability

exposure for the in-service fleet and newly manufactured aircraft.

3. Pursue the studies associated with directed ventilation and ground-based inerting

systems to improve their cost effectiveness.

4. If a practical means of achieving a cost effective reduction in flammability

exposure can be found for the in service fleet, either at the level specified in the

rule or at some intermediate level (recommendations 2 and 3 above), consider

application of that solution, in combination with other actions (e.g. SFAR).

5. If a practical means of achieving a cost effective reduction in flammability

exposure can be found for newly manufactured aircraft, either at the level specified

in the rule or at some intermediate level (recommendations 2 and 3 above),

consider application of that solution, in combination with other actions (e.g.

SFAR).

Recommended Implementation Plan

Proposed Action In-Service

Aircraft

New Production

Aircraft

New Type Design

Aircraft

Flammability

Reduction

Pursue practical

means

Pursue practical

means

Apply new rule

SFAR Apply Apply Apply

AFSSP Apply Does not apply Does not apply

Note:

The proposed ignition source prevention regulation (FAR/JAR 25.981 (a)), and

supporting AC/ACJ, were outside the terms of reference of the ARAC Working

Group and no effort was expended on these tasks. However, the group believes that

the FAA/JAA should work with a similar group to finalize this action.
FUEL TANK HARMONIZATION WORKING GROUP

FINAL REPORT

Page 36 of 36

REFERENCE MATERIAL

ATTACHMENTS

1) TOR

2) Organizational Chart

3) Task Group 1 - Service History/Fuel Tank Safety Level Assessment Final Report

4) Task Group 2 - Explosion Suppression Final Report

5) Task Group 3 – Fuel Tank Inerting Final Report

6) Task Group 4 – Foam Final Report

7) Task Group 5 – Fuel Vapor Reduction Final Report

8) Task Group 6/7 – Fuel Properties and Its Effects on Aircraft and Infrastructure Final Report

9) Task Group 8 – Evaluation Standards and Proposed Regulatory Action Advisory Group

Final Report
ARAC FTHWG Final Report Layout

1. Executive Summary

2. TOR

3. Organizational Chart

4. Task Group 1 – Service History/Fuel Tank Safety Level Assessment Final Report

5. Task Group 2 – Explosion Suppression Final Report

6. Task Group 3 – Fuel Tank Inerting Final Report

7. Task Group 4 – Foam Final Report

8. Task Group 5 – Fuel Vapor Reduction Final Report

9. Task Group 6/7 – Fuel Properties - Effect on Aircraft and Infrastructure Final Report

10. Task Group 8 – Evaluation Standards and Proposed Regulatory Action Advisory Group Final Report
Fuel Tank Harmonization

Working Group

ARAC FTHWG Working Group

Co-Chairmen

AIA Representative & AECMA Representative

Fuel Tank

Foam

(4)

Service History /

Fuel Tank Safety 

Level Assessment

 (1)

GAMA 

FAA

IATA

ALPA

ATA

JAA

Explosion

Suppression

(2)

Fuel Tank

Inerting

 (3)

Tank Cooling &

Ullage Sweeping

(Fuel Vapor

Reduction)

(5) 

Fuel 

Properties -

Infrastructure and 

Aircraft Affects

(6/7)

Evaluation

Standards 

Advisory & Proposed

 Regulation

Action

(8)

Executive Assistant 

to the Chairmen AIA

AECMA

API

Date: 07-14-98
Service History/Fuel Tank

Safety Level Assessment

Task Group 1

Aviation Rulemaking

Advisory Committee

ARAC

JAA FAA

THE PUBLIC
14 July 1998

Task Group 1 1

Task Group 1

Service History and Safety Assessment

at 1 July 1998
14 July 1998

Task Group 1 2

Summary

Task Group 1 was initially charged with providing “An analysis of the threat of fuel tank

explosion due to internal and external tank ignition sources for the major fuel system

designs making up the transport fleet, including transport airplanes with heat sources

adjacent to or within the fuel tanks.”

This was interpreted as a requirement to carry out a detailed analysis of previous tank

explosion events, and to carry out a flammability review of the current range of fuel

system designs and tank configurations. A further task was then added to prepare a

safety analysis to evaluate the safety impacts of any proposed (design) changes

recommended by the other groups. Task Group 1 successfully discharged each of

these responsibilities, although the detailed flammability review was transferred to (and

discharged by) Task Group 5.

Review of Service History

A review of the records of the last 40 years of transport airplane operations worldwide

revealed a total of 16 tank explosions relevant to this study. Analysis of these events

showed that the fuel tank location was a major factor. In comparing explosion events in

integral wing tanks with those located in or adjacent to the fuselage (known as “center

tanks”), it was found that the rate of center tank events was considerably higher than

one would expect. It was also found that whereas corrective actions to prevent

recurrence of the wing tank events were in place, the exact ignition sources in the two

most recent center tank events have not been identified, and do not yet have proven

remedies.

It was concluded that flammability reduction measures which would reduce the rate of

center tank explosions down to the level attained by wing tanks should be investigated.

Safety Assessment

Top-level functional hazard analyses (FHA’s) were performed for each option to identify

the significant failure conditions these options might bring to the airplane. It was noted

that whereas some of the options exhibited relatively benign failure conditions, others

had the potential to cause Hazardous or Catastrophic events. However, it was

concluded that proper design techniques were available to reduce the frequency of

these latter failure conditions to levels consistent with the requirements of FAR/JAR

25.1309. The only exception to this statement was the Explosion Suppression option,

where it was not clear that the technology was sufficiently mature to permit

identification of all its potential failure modes with confidence.
14 July 1998

Task Group 1 3

Contents

Summary ...............................................................................................................2

1. Introduction .......................................................................................................4

2. Working Practices.............................................................................................5

3. Review of Service History .................................................................................5

3.1 Details of previous tank explosions....................................................................................5

3.2 Analysis of previous tank explosion events ........................................................................5

Table 1 - Summary of Operational Events...............................................................................6

Table 2 - Summary of Refuelling and Ground Maintenance Events .........................................7

Table 3 - Aircraft Damage and Fatalities..................................................................................9

3.3 Service History Conclusions ............................................................................................10

4. Fuel Tank Configurations................................................................................10

5. Safety Assessment..........................................................................................11

5.1 Objectives .......................................................................................................................11

5.2 Analysis Methods.............................................................................................................11

5.3 Analyses..........................................................................................................................11

5.3.1 Gaseous inerting.......................................................................................................12

5.3.2 Foam ........................................................................................................................13

5.3.3 Ullage sweeping........................................................................................................14

5.3.4 High flash-point fuel..................................................................................................15

5.3.5 Heat reduction ..........................................................................................................16

5.4 Safety Assessments Conclusions.....................................................................................16

Appendix A - Details of previous tank explosions ...............................................17
14 July 1998

Task Group 1 4

1. Introduction

This report describes the work carried out by Task Group 1 to accomplish the tasks

outlined below.

The objectives for Task Group 1 were derived from the Terms of Reference for the Fuel

Tank Harmonization Working Group (FTHWG), as published in the Federal Register on

23rd January, 1998. Those Terms of Reference included a task to provide:

“An analysis of the threat of fuel tank explosion due to internal and external tank

ignition sources for the major fuel system designs making up the transport fleet,

including transport airplanes with heat sources adjacent to or within the fuel tanks.”

This task was assigned to Group 1, and was further developed at the first Working

Group meeting in Washington D.C. into the following three sub-tasks:

(1) Carry out a detailed analysis of previous tank explosion events, in order to

determine whether any further information could be gained regarding the

contributory effects of fuel type, tank location, system design philosophy,

environment etc. on the incidence of tank explosions.

The objective was to better identify those circumstances in which there is an

increased likelihood of explosion, such that these could be minimized in the

future, and also to identify configurations/circumstances where the risk had been

shown to be low such that these could be used to guide design practice in the

future.

(2) Carry out a flammability review of the current range of fuel system designs

and tank configurations by first creating a matrix of major types of fuel tank

configurations, and then to assess the flammability levels currently existing within

a representative selection of those fuel tanks.

However, it became clear during early discussions that members of Task Group 5

(Fuel Vapor Reduction) already possessed the analytical tools to complete this

task. It was therefore agreed that Group 1 should compile the tank

configurations matrix and pass it to task Group 5, which would then carry out

flammability analyses.

The objective of this work was to define those configurations most at risk if an

ignition source were present, such that these areas received particular attention

when considering future rule changes or aircraft modifications.

(3) Prepare a safety analysis to evaluate the safety impacts of any proposed

(design) changes recommended by the other groups.

The aim was to provide a consistent means of assessing the safety effects of

each of the options, and to indicate the level of complexity such systems might

require in order to meet any new rules regarding flammability and meet existing

rules governing system failure conditions (e.g. JAR/FAR 25.1309).
14 July 1998

Task Group 1 5

2. Working Practices

Group 1 comprised four members. Two came from a propulsion design and

certification background with aircraft manufacturers. The third member was an airline

fleet engineering manager who participated in the TWA800 accident investigation, and

the final member came from the propulsion certification office of the FAA.

The group discharged its various tasks through the individual efforts of its members,

and held regular reviews of its progress through data exchange, through dedicated task

group meetings, and through presentations and reviews of its work in front of the full

Working Group on a monthly basis. In addition, because of the relationship and interdependence of the tasks of Groups 1, 5 and 8, these teams also held periodic joint

meetings to exchange findings and ideas.

3. Review of Service History

The service history of the transport airplane fleet (including turbofan and turboprop

airplanes) over the last 40 years was examined, and information regarding known

instances of fuel tank explosion (other than those caused by post-impact crash events)

was assembled. The starting point was the table of events contained in the FAA Notice

on Fuel Tank Ignition Prevention Measures published in the Federal Register on April 3,

1997. The data sources used were accident and incident reports provided by

investigating organizations, regulatory authorities, and original equipment

manufacturers’ safety-related databases. The level of details reported in the early

events was sometimes limited dependent on the event location in the world and the

type of event (whether it involved an internal or external ignition source).

3.1 Details of previous tank explosions

Appendix A contains a detailed description of each event and the findings of the

investigating authority, followed by a description of the mitigating actions taken

subsequent to the event to prevent its recurrence.

3.2 Analysis of previous tank explosion events

The 16 tank explosion events are summarized on Tables 1 and 2. They have been

separated into Operational Events (i.e. those occurring on an airplane where

passenger-carrying flight was intended), and Refuelling & Ground Maintenance Events.

They are grouped by cause (Lightning, Engine Separation, Refuelling, Maintenance,

etc.), and are then categorized by operational phase, ignition source, type of fuel tank

involved, and fuel type. The mitigating actions taken subsequent to each event are

summarized, and any recurring events are identified.

Table 3 gives details of the aircraft damage and lives lost due to tank explosions.
14 July 1998

Task Group 1 6

Table 1 - Summary of Operational Events

1963

Lightning

Elkton

707

1976

Lightning

Madrid

747

1965

UCEF/Eng sep

San Francisco

707

1970

Eng Sep

Toronto

DC-8

1990

Eng Sep

New Delhi

747-200

1992

Eng Sep

Marseilles

707

1989

Sabotage

Bogota

727

1990

Unknown

Manila

737-300

1996

Unknown

New York

747

Operational Phase Inflight • • • • • • • •

On Ground Operations •

Ground Maintenance

Refuelling

Ignition Source Lightning • •

Overwing Fire - Inflight • • • •

Static Discharge

Sabotage •

Unknown • •

Tank Type Main (Wing) = W

Center = C

W W W W W W C C C

Fuel Type JP-4 / Jet A JP-4 / Jet A Jet A JP 4 Jet A Jet A Jet A Jet A Jet A

Mitigating action

taken to minimize or

prevent

Airplane Design Change •

Flow-thru’ vent;

surge tank

suppression

•

Improved

bonding inside

tank

•

Redundant control

of spar shutoff valve

•

Spoiler Lockout

Mechanism

•

Flame Arrestors

on Pump Inlets

recurrence of root

cause

Hardware Inspection

Requirements

•

Mid-spar attach’t

repeat inspection

•

12 Service

Bulletins

•

12 Service

Bulletins

Ground Support Equipment

Change

Maintenance Program /

Procedures Revised

• • •

Operations Bulletin •

Improved Airport Security • •

None

Unknown

Recurring Event •

Different

cause

•
14 July 1998

Task Group 1 7

Table 2 - Summary of Refuelling and Ground Maintenance Events

1970

Refuelling

Minneapolis

727

1970

Refuelling

Minneapolis

727

1973

Refuelling

Toronto

DC-8

1989

Refuelling

Washington

Beechjet 400

1967

Ground Maint.

Taiwan

727

1974

Ground Maint.

Travis AFB

DC-8

1982

Parked

Montreal

DC-9

Operational Phase Inflight

On Ground Operations

Ground Maintenance • • •

Refuelling • • • •

Ignition Source Lightning

Overwing Fire - Inflight

Static Discharge • • • •

Sabotage

Unknown • • • Suspect dry

running boost pump

Tank Type Wing = W Rear Aux = RA

Center = C Fwd Aux = FA

C C W RA C W FA

Fuel Type Jet A Jet A JP-4 / Jet A Jet A / JP-4 Jet A JP-4 Jet A

Mitigating action

taken to minimize or

prevent

Airplane Design Change •

Installed conductive

foam

recurrence of root

cause

Hardware Inspection

Requirements

Ground Support Equipment

Change

•

“Anti-static” filters

introduced

Maintenance Program /

Procedures Revised

•

(probable outcome)

• • •

(probable outcome)

Operations Bulletin

Improved Airport Security

None •

Unknown

Recurring Event •
14 July 1998

Task Group 1 8

From Tables 1 and 2, certain patterns and trends emerge:

• There are 8 wing tank events, and 8 involving center or fuselage tanks

• In the wing tank events, 5 out of 8 involved the use of wide-cut fuel (JP-4/Jet B)

• In the wing tank events, 5 out of 8 occurred in flight

• All the wing tank events involved external ignition sources - there are no known

wing tank explosions due to internal ignition sources in 520 million hours of flight

operations

• There were only 2 explosions due to lightning strike, with 396 million flight hours

accumulated since the last event in 1976

• All the center tank events involved the use of Jet A/Jet A-1 fuel

• In the center tank events, 6 out of 8 occurred on the ground

• There are 9 operational events, and 7 refuelling and ground maintenance events

From the data, there appears to be a difference in the respective safety levels of wing

tanks and center tanks.

All the wing tank events have been due to known, external ignition sources (lightning

strikes, over-wing fire, refuelling, maintenance error) - there are no known internal

ignition sources in 520 million hours of commercial transport fleet operation that

resulted in a tank explosion. Corrective actions to prevent recurrence of these wing

tank events have been in place for many years, and have been demonstrated to be

effective.

By contrast however, in the two most recent center tank events the exact ignition

sources have not been identified. Whilst corrective actions to identify and eliminate

potential ignition sources are now being put in place, the investigation of flammability

reduction is warranted since the efficacy of these actions has yet to be proven.

Over the years, center tanks have accumulated considerably fewer operating hours

than wing tanks (for example, a B-737 has two wing tanks and one center tank, and

therefore accumulates wing tank hours at twice the rate of center tank hours). Since

the equipment in wing and center tanks is very similar, i.e. there are similar types and

numbers of potential ignition sources, one would expect there to be significantly fewer

center tank events than wing tank events. Actually the numbers of events are equal.

This indicates that center tanks are significantly more susceptible to explosion than

wing tanks.

It might be argued that the reason for this disparity is that components in the wing tanks

are more often submerged than those in the center tanks, which often operate almost

empty. However, this may be an over-simplification. There are several pieces of

equipment inside wing tanks which routinely operate in the vapor space, such as fuel

quantity probes and wiring, and partially submerged boost pumps. There is still

considerable potential for the existence of ignition sources within the ullage of wing

tanks. This being the case, if center tanks are experiencing considerably more

explosions than might be expected relative to wing tanks, it must be that center tanks

are significantly more flammable than wing tanks. Reducing the flammability in center

tanks down to wing tank levels would be a worthwhile goal.

In the last 20 years (when Jet A has been the predominant fuel), there have been five

tank explosion events involving center/fuselage tanks, and two wing tank events (which

were both exceptional ones - see Appendix A, Event nos. 3 & 4). The continuing
14 July 1998

Task Group 1 9

incidence of center tank explosions (all of which involved Jet A fuel) indicates that

these tanks have not yet reached the safety level attained by wing tanks, and that

action to further reduce the flammability levels in center tanks should be considered.

Table 3 summarizes the numbers of fatalities and degree of aircraft damage resulting

from all the events. As discussed earlier, the Manila B-737 and New York B-747 events

are the only ones for which the corrective actions have not been proven in subsequent

airline service. In any cost/benefit analyses performed elsewhere in this study, it is

recommended that only those lives lost in these last two events should be counted,

since formal or informal cost/benefit analyses have already been performed on the

earlier events when the decisions were taken regarding the follow-on actions from

those events. A total of 238 lives were lost in the two most recent events.

Table 3 - Aircraft Damage and Fatalities

Operational Events No. of Events No. of Fatalities

Hull loss with fatalities 6 539

Hull loss 2

Substantial damage 1

Non-Operational Events

Hull loss with fatalities 1 1

Hull loss 2

Substantial damage 4 1

Totals 16 541
14 July 1998

Task Group 1 10

3.3 Service History Conclusions

This study identified and analyzed 16 known instances of fuel tank explosions (other

than those following impact with the ground) over the last 40 years of transport aircraft

operations worldwide. The following conclusions have been drawn:

• There is a close relationship between the incidence of explosions in wing tanks and

the use of wide-cut fuel.

• Wing tanks operating with Jet A type fuel have demonstrated an acceptable safety

record.

• In comparison, center tanks and fuselage-mounted tanks are more vulnerable to

explosion in the presence of ignition sources.

• Apart from the two most recent events (1990/Manila & 1996/New York), the causes

of all the other events have been addressed by actions designed to prevent or

minimize their recurrence.

It is recommended that action to further reduce the flammability levels in center tanks

should be considered.

4. Fuel Tank Configurations

An extensive survey of fuel system and fuel tank configurations was conducted for the

commercial transport aircraft fleet. A tabular summary was compiled for 68 different

aircraft types or models, including large, medium and small turbofan aircraft, regional

jets, business jets and turboprop aircraft. This described the aircraft in terms of size

and range, and characterized the wing and tank configurations, the fuel capacity and

presence of adjacent heat sources for each aircraft fuel system.

On completion, it was passed to Task Group 5 to facilitate selection of suitable

candidate aircraft types on which to perform flammability analyses.
14 July 1998

Task Group 1 11

5. Safety Assessment

5.1 Objectives

As stated earlier, the third task assigned to Group 1 was to assess the overall aircraftlevel safety implications of carrying out the modifications being investigated by the

other Task Groups. Clearly, since some of these modifications involve technologies

which are currently not fully mature or proven in a commercial airline environment,

rigorous and detailed safety analyses down to component level could not be carried out

with confidence. However, the safety assessments described below do allow some

useful comparisons to be made regarding the safety impacts of the various options

relative to each other. They also provide an indication of the complexity or levels of

redundancy which such systems may require in order to meet the certification

requirements of FAR 25.901(c) and JAR/FAR 25.1309.

5.2 Analysis Methods

A top-level functional hazard analysis (FHA) was performed for each option. This

typically looks at the effects of the system not operating when required, and operating

when not required, and identifies the severity of these failure conditions (using the

guidance contained in Advisory Circular AC 25.1309-1A).

For each system being analyzed, Group 1 made extensive use of the more detailed

knowledge of the individual task group “responsible” for that system.

The following options were the subject of safety assessments:

• Filling the ullage space with inert gas

• Filling the tank with foam

• Purging fuel vapor from the tank

• Raising the flash point of the fuel

• Reducing the heat input into the fuel

Due to the lack of commercial aircraft operational experience with explosion

suppression systems, the technology was not considered sufficiently mature or wellunderstood to merit carrying out an analysis of its safety implications.

5.3 Analyses

For each of the “explosion protection” systems analyzed below, the condition where

they failed to operate when required was classified as Minor since loss of the protection

system on its own does not significantly reduce airplane safety. Clearly, loss of

protection coupled with an ignition source in a flammable atmosphere would be

considered a Catastrophic event. This combination of failures is the case which would

actually set the required reliability (availability) of the protection system.
14 July 1998

Task Group 1 12

5.3.1 Gaseous inerting

The gaseous inerting system is assumed to be one which actively replaces the oxygen

component of the air inside the tank(s) such that the resulting fuel vapor/gas mixture is

too rich to be flammable. Further, it is assumed that this requires the tank to be closed

from the atmosphere to prevent dilution of the inerting agent and re-oxygenation of the

ullage.

The gaseous inerting system has the following functions:

(1) To keep the oxygen concentration inside the tank below the level which will

support combustion

(2) To keep the tank differential pressure within limits

(3) To prevent leakage of inert gas into the passenger cabin or flight deck

The functional failures are documented below.

Function: (1) To keep the oxygen concentration inside the tank below the level which

will support combustion

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Fails to prevent ullage volume

becoming flammable

(A) Explosion possible if

ignition source present

(B) None unless ignition

source present

(C) None unless ignition

source present

Minor N/A Loss of protection returns tank to pre-mod

condition, i.e. only vulnerable to explosion if

flammable atmosphere and ignition source

present

Operates inadvertently during

tank maintenance

(A) Oxygen concentration

inside tank depleted

(B) None

(C) Asphyxiation of

maintenance personnel

Hazardous 1 x 10-7 per

hour

May require system inhibition interlocks as

well as explicit maintenance procedures

Function: (2) To keep the tank differential pressure within limits

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Allows tank differential to

exceed maximum positive

limits

(A) Wing over-pressure

deformation

(B) Loss of structural integrity

(C) Multiple loss of life

Catastrophic 1 x 10-9 per

hour

Need dual-redundant vent valves, and an

over/under-pressure relief valve

Allows tank differential to

exceed maximum negative

limits

(A) Wing under-pressure

deformation

(B) Loss of structural integrity

(C) Multiple loss of life

Catastrophic 1 x 10-9 per

hour

Need dual-redundant vent valves, and an

over/under-pressure relief valve
14 July 1998

Task Group 1 13

Function: (3) To prevent leakage of inert gas into the passenger cabin or flight deck

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Transfers inert gas into cabin (A) Possible loss of tank

inerting

(B) None (unless pilots

incapacitated)

(C) Incapacitance/death of

some occupants before

oxygen masks deployed

Hazardous 1 x 10-7 per

hour

Consider N2 detector in cabin

5.3.2 Foam

The foam “system” is assumed to comprise multiple small blocks of highly porous

material which completely fill the tank interior, with negligible voids. It prevents gross

over-pressure or explosion within a tank by limiting the extent of any vapor/air ignition

to a small local detonation, preventing it propagating throughout the tank.

The foam “system” has the following functions:

(1) To prevent ignition of the fuel vapor/air mixture from causing a tank explosion

(2) To allow free movement of fuel within the tank and into the fuel delivery system to

the engine(s)

The functional failures are documented below.

Function: (1) To prevent ignition of the fuel vapor/air mixture from causing a tank

explosion

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Fails to protect against ignition

propagating into tank

explosion

(A) Explosion possible if

ignition source present in

flammable atmosphere

(B) None unless ignition

source present

(C) None unless ignition

source present

Minor N/A Loss of protection returns tank to pre-mod

condition, i.e. only vulnerable to explosion if

ignition source and flammable atmosphere

present
14 July 1998

Task Group 1 14

Function: (2) To allow free movement of fuel within the tank and into the fuel delivery

system to the engine(s)

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Interruption of fuel flow to the

engine(s)

(A) Blockage of fuel supply to

engine(s)

(B) Possible multiple engine

power loss requiring forced

landing

(C) Serious injury/death of

some occupants

Hazardous 1 x 10-7 per

hour

Life limits for foam. Increased/redesigned

filtration and increased frequency of filter

inspections

Inability to transfer fuel out of

a tank

(A) Fuel trapped within a tank

(B) Loss of range requiring

diversion

(C) None

Major 1 x 10-5 per

hour

5.3.3 Ullage sweeping

An ullage sweeping system is one which the fuel vapor is purged from the tank ullage

using forced ventilation, making the ullage too lean to be flammable.

The ullage sweeping system has the following functions:

(1) To keep the fuel vapor concentration inside the tank below the level which will

support combustion

The functional failures are documented below.

Function: (1) To keep the fuel vapor concentration inside the tank below the level

which will support combustion

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Fails to prevent ullage volume

becoming flammable

(A) Explosion possible if

ignition source present

(B) None unless ignition

source present

(C) None unless ignition

source present

Minor N/A Loss of protection returns tank to pre-mod

condition, i.e. only vulnerable to explosion if

flammable atmosphere and ignition source

present
14 July 1998

Task Group 1 15

5.3.4 High flash-point fuel

This option uses fuel whose flash point has been raised from the current minimum

value of 100°F to a significantly higher value (say 120°F). It prevents a fuel tank

explosion by maintaining the flash point above the highest temperature attainable

inside a fuel tank.

High flash fuel has the following functions:

(1) To prevent formation of a flammable vapor/air mixture within the operating

temperature envelope of a fuel tank interior

(2) To provide a fuel suitable for aircraft gas turbine engine operation

The functional failures are documented below.

Function: (1) To prevent formation of a flammable vapor/air mixture within the

operating temperature envelope of a fuel tank interior

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Allows formation of a

flammable vapor/air mixture

inside the tank

(A) Explosion possible if

ignition source present

(B) None unless ignition

source present

(C) None unless ignition

source present

Minor N/A Loss of protection returns tank to pre-mod

condition, i.e. only vulnerable to explosion if

flammable atmosphere and ignition source

present

Function: (2) To provide a fuel suitable for aircraft gas turbine engine operation

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Fuel causes engine

malfunction

(A) Flameout

(B) Possible multiple engine

power loss requiring forced

landing

(C) Serious injury/death of

some occupants

Hazardous 1 x 10-7 per

hour

Rigorous engine/airframe compatibility

testing required, possibly with controlled

service introduction & fleet leader program
14 July 1998

Task Group 1 16

5.3.5 Heat reduction

This option is intended to minimize the heat added to the fuel once it is onboard the

aircraft by insulating, ventilating or otherwise physically separating heat sources from

fuel tanks. The intent is to prevent raising the fuel vapor above its flash point.

The heat reduction option has the following functions:

(1) To prevent the fuel vapor inside a tank being raised above its flash point

The functional failures are documented below.

Function: (1) To prevent the fuel vapor inside a tank being raised above its flash point

Functional Failure Failure Condition

Effect on (A) System, (B)

Aircraft, (C) Occupants

Classification Probability

Requirement

Safety Design Implications

Allows fuel temperature to rise

above its flash point

(A) Explosion possible if

ignition source present

(B) None unless ignition

source present

(C) None unless ignition

source present

Minor N/A Loss of protection returns tank to pre-mod

condition, i.e. only vulnerable to explosion if

flammable atmosphere and ignition source

present

5.4 Safety Assessments Conclusions

The top-level safety analyses above indicate that some of the options under

consideration could exhibit undesirable failure conditions. However, it is considered

that all of these systems could be designed with sufficient integrity to meet the

requirements of FAR 25.1309 such that the overall safety of a given fleet of airplanes

was not compromised. For some of the options, meeting those requirements would

require greater system complexity and (possibly) more onerous inspection and

maintenance requirements than the options with benign failure conditions. A

comparison of the relative merits of these options is therefore primarily an economic

consideration, since all of the options could be made equally safe.
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Appendix A - Details of previous tank explosions

Appendix A contains a detailed description of each event and the findings of the

investigating authority, each followed by a description of the mitigating actions taken

subsequent to the event to prevent its recurrence. The 16 events have been grouped

initially into broad categories which characterize their circumstances, i.e. engine

separation events, lightning strike events, ground maintenance events, refuelling

events, “others” and those where the cause remains unknown.

Engine Separation Events

1. Date: 28 June 1965 Flight phase: Takeoff climb

Aircraft: Boeing 707 Tank type: Main reserve tank

Location: San Francisco Fuel type: Jet A

Summary of Event

Approximately 39 seconds after takeoff No.4 engine experienced an uncontained

engine failure resulting in separation of the engine from the wing. The loss of the

engine resulted in mechanical damage to the wing and a severe fire. The fire triggered

a low order explosion in the No.4 reserve tank which resulted in the loss of the lower

wing skin, lower stringers, and spar chord flanges. The loss of these components

resulted in the loss of wing integrity which allowed the outer wing panel to fail and

separate from the wing. The ensuing fire was extinguished by the closing of the main

fuel shutoff valve either by the first officer or the flight engineer.

There was evidence of fire on the separated wing section, on the remaining wing

around the point of separation, and on the No.4 engine. Fire was observed by ground

witnesses, passengers and crew members, and photographed, in color, from the

ground and by a passenger. The flight crew was alerted to the fire when an intermittent

fire warning was observed while they were going through the engine shutdown

procedure following the failure of the No.4 engine. The first officer then actuated the

fire selector lever for the No.4 engine and discharged both fire extinguisher bottles to

the engine. The fire was observed streaming from the right wing. Fuel was still

streaming from the No.4 tank area after landing until the fire department plugged the

hole in the bottom of the tank. The area around the fuel spill and the wing stub were

foamed as a preventative measure while the passengers were disembarking from the

aircraft.

Analysis

A disk failure resulted in an explosive failure of the No.4 engine and its separation from

the wing due to high vibration and out of balance oscillation of the rotating parts of the

engine. The right outer wing received so much damage to the lower load-bearing skin

and associated structure that capability of the wing to sustain in-flight loads were

reduced below the loads imposed, and the outer wing panel separated from the wing.

Fuel from the engine fuel line was then being pumped directly into the airstream. This

fuel was ignited by an undetermined source shortly after the engine separated and

resulted in an explosive separation of a portion of the lower wing skin. It is believed

that dangling wires from the engine separation sequence ignited the fuel. The fire was

sustained by the continued supply of fuel through the engine fuel line until the flight

engineer or the first officer shutoff the main fuel supply either by activating the fuel

shutoff valve to the closed position or actuating the fire selector handle.
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The disintegration of the third stage turbine disk cut the engine in two pieces and threw

turbine debris into the wing inboard of the engine pylon. The two engine sections, each

supported by only one mount on the strut, began to oscillate and separated from the

wing in approximately four seconds. The strut failures were caused by the oscillation,

possibly coupled with mechanical damage from flying engine parts. The engine fuel

line pulled from the strut closure rib when the engine separated from the wing. Fuel

was pumped through this line for an estimated 99 seconds at a rate of approximately

30,000 pounds per hour, until the fuel valve was shut off by the action of either the first

officer or the flight engineer. A second fuel source was the fuel line on the forward face

of the main spar which had a loosened fitting that leaked and supplied fuel for a fire

over the strut center spar between the front spar and the nacelle closure rib. A third

possible flammable fluid source was the ruptured slat hydraulic line on the inboard gap

cover area.

The source of the ignition cannot be determined, but the possible sources included the

engine exhaust, hot turbine parts, or arcing from exposed electrical leads. The latter is

the most probable source because there was an appreciable time lapse between

observation of the fuel spray and ignition. The fuel sources wetted much of the upper

wing surface before ignition occurred.

The fact that No.4 main tank was full of fuel probably prevented more extensive fire

damage to that area of the upper wing surface because the fuel acted as a heat sink.

The fire in this area reached temps ranging from approximately 870 - 1165°F, based on

damage caused to the metal.

The damage to the right outboard wing section top and bottom skin and ribs could only

have been caused by an over-pressure in the reserve tank. This is demonstrated

particularly by the manner in which the lower skin separated from the aircraft. The

entire panel was forced straight down, taking the attaching flanges of both spars with it.

This is plainly the result of a low order explosion. The source of ignition for this

explosion could not be determined but could have been auto-ignition, burn through, or

hot surface ignition from a localized hot spot.

The final separation of the wing followed the explosion in the reserve tank. The wing

separation is not believed to have been simultaneous with the explosion. The

indications of yaw and vertical oscillation on the flight recorder readout and the location

of the wreckage on the ground indicate that the wing section remained on the aircraft

approximately 10-11 seconds after the separation of the lower skin panel.

The heat damage to the wing structure was not considered to have been a major factor

in the wing failure. Rather, the loss of lower skin panel, stringer, mid spar chord flanges

reduced the load carrying capability of the wing below that required to support a 1 “g”

condition, thus leading to the failure.

Laboratory tests of the fuel samples taken from the six remaining fuel tanks on the

aircraft revealed no significant deviation from the specification established for Jet A

turbine engine fuel. It was estimated that the fuel temperature in the tanks at the time

of the accident was between 70-80°F. The flammability limit of Jet A fuel was reported

by the FAA to be from 90-170°F. Ambient temperature prior to the flight were recorded

as 77°F.

Mitigating Actions Taken:

Airplane design change were made to incorporate redundant wiring paths to close spar

and engine high pressure valves when the fuel shutoff or fire handle switch is activated.

Engine assembly procedures were modified to ensure proper running clearances.

There has been no recurrence of an engine uncontained failure leading to separation
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Task Group 1 19

of the wing since design changes.

2. Date: July 1970 Flight phase: Go-around

Aircraft: McDonnell Douglas DC-8 Tank type: Wing tank

Location: Toronto Fuel type: JP-4

Over the threshold of runway 32 at about 60 feet agl, the first officer deployed, instead

of arming, the ground spoilers causing a rapid descent until striking the ground. The

captain tried to compensate by applying full power and rotating the airplane to initiate a

go-around. However, the airplane hit hard at 18 feet per second, number 4 engine

separated and number 3 engine partially separated. Somewhere in the sequence of

the engine separation from the wing, leaking fuel that may have been ignited by

dangling wires causing some explosions. The airplane continued with go-around while

trailing fuel and fire. Airplane climbed to 3,100 feet and commenced a turn for a

second approach. The right wing separated above the number 3 engine, the airplane

rolled over and struck the ground . The airplane crashed 2.5 minutes following

touchdown and approximately 8.5 miles from runway 32. The FAA has reported that

JP-4 fuel was being used. Ambient conditions were reported as warm and sunny.

Mitigating Action Taken:

As a result of this accident, the FAA issued an airworthiness directive (AD) requiring

placard warnings against in-flight deployment of ground spoilers by DC-8 operators.

Following a non-fatal accident some three years after this crash, the FAA issued

another AD requiring that all aircraft of the type be fitted with spoiler locking

mechanisms to prevent such an occurrence.

3. Date: 7 May 1990 Flight phase: Landing

Aircraft: Boeing 747-200 Tank type: No 1 wing tank

Location: New Delhi, India Fuel type: Jet A

A 747-200 operating a flight from London to New Delhi landed at Delhi at 0915 local

time. The flight crew reported there were no problems experienced with the No. 1

engine during the London-Delhi flight. Touchdown and engine transition to reverse

thrust were reported as normal. Shortly after the engines reached full reverse, all No. 1

engine indications apparently went to zero. The flight crew was not aware of the nature

or extent of the problem at this point as there was no engine fire warning. Another 747,

which had landed five minutes earlier, advised the 747-200 they had a large fire on the

left wing in the area of No. 1 engine. The crew reportedly pulled the No. 1 fire handle

and discharged the fire extinguisher. The tower also noted the fire and alerted the

aircraft and the airport fire department. The fire department was already aware of the

situation and had four fire engines on the scene within two minutes of first noting the

fire. The fire was reportedly extinguished within eight minutes of the first report.

All 175 passengers and 20 crew members were evacuated using the five main deck

slides on the right side of the aircraft. All five slides deployed normally and were used.

There were no reported injuries of anyone on board. The aircraft apparently touched

down between one and two thousand feet from approach end of the runway. Weather
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Task Group 1 20

was clear and dry with little or no wind and the temperature was 35°C. First evidence

of the No. 1 engine inlet cowl contacting the runway was at three thousand feet.

Spatters of molten aluminium were first noted at above five thousand feet from

approach end. The aircraft stopped ten thousand feet from approach end slightly to left

of center. The No. 1 engine was in a near vertical position. The engine had rotated

around the mid spar attach points with the nose cowl resting on the runway and the

exhaust plug and engine tail pipe jammed against the wing lower surface. The No. 1

strut upper link forward attach fuse pin was sheared. Pieces of fractured fuse pin

remained in the upper link forward clevis fitting and associated strut attach lug. The aft

end of the diagonal brace was detached from its associated fitting on the lower wing

skin and the associated fuse pin was completely missing, and could not be found.

Failure of these two strut attach points allowed the front of the engine to drop,

contacting the runway. All equipment in the No. 1 strut sail boat area was destroyed by

impact with strut aft bulkhead, engine exhaust pipe, tail cone and subsequent fire.

The No. 1 engine fuel supply line separated at the wiggins fitting between strut

bulkhead and wing front spar. All wire bundles to the engine appeared to have been

broken due to tension caused by the strut rotating to a vertical position. All leading

edge flaps and leading edge fiberglass panels severely burned inboard and outboard

of No. 1 strut. The outboard end of the outboard trailing edge flap was severely

burned. The outboard flap track fairing was totally consumed by fire. The inboard end

of the outboard aileron was severely burned. The outboard spoilers 1 and 2 and the

trailing edge fiberglass panels inboard and outboard of the No. 1 strut was severely

burned. The left wing tip was drooping down outboard of the No. 1 strut at about 15

degrees. There was evidence of extreme heating and warping of upper wing skin

above the No. 1 strut. The upper wing skin was pulled loose from the forward and aft

spar webs outboard of the No. 1 strut. Vent stringers were split open longitudinally. All

upper wing skin rivets were pulled through the skin in the area of the surge tank. The

lower wing skin was scorched in area of surge tank.

Analysis

In brief summary, the fuel from the ruptured fuel line and hydraulics in the strut were

ignited by the hot engine and exhaust, followed by auto ignition of residual fuel in the

reserve and surge tanks due to external heating. Fuel supply to the fire was terminated

prior to the aircraft coming to rest and flammable wing and subsystem material

continued to burn until extinguished by ground personnel.

Following forward strut pin failure and engine dropping nose down:

• Fuel is discharged at approximately 100 gpm into air stream prior to engine spar

valve closure due to fuel line separation from front spar coupling. Fuel is washed

under and possibly over wing and into leading edge cavity due to both forward

speed of aircraft and due to thrust reverser air from engine.

• Due to engine exhaust/tailpipe being rotated up which forced diagonal brace into

the hydraulic reservoirs in strut aft fairing, reservoir is crushed and 10 gallon (U.S.)

hydraulic fluid is released.

• Fuel and/or hydraulic fluid is ignited on hot engine tail cone/nozzle.

• Hot engine exhaust gases and/or fuel fire heat the lower surface of reserve tank.

Reserve tank is empty, but air is heated in excess of fuel AIT (auto ignition

temperature). Residual undrainable fuel is approximately one U.S. gallon.

• Heated air or burning fuel vapor reaches surge tank through the reserve tank vent

line. Fire initiates in surge tank due to residual fuel vapors and temperature in
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Task Group 1 21

excess of AIT for fuel. Hot front spar at surge tank due to leading edge fire could

also have been the ignition source.

• Main tank No. 1, because of fuel acting as a heat sink, remains "cool".

• Wing leading edge receives fuel spray or mist due to engine thrust reverser air or

free stream air dispersion. Prior to fuel shutoff, during landing roll, fuel attaches to

flap torque tubes and interior flap surfaces, and subsequently burns. Resin binding

agents in fiberglass honeycomb panels will burn when fed by heat of fuel fire. Fuel

was shut off prior to the end of the landing roll as evidenced by soot being confined

to aft portions of strut and aft part of core cowl.

Fire damage to aft end of engine is primarily to exterior cowling and exterior surface of

nozzle. Inner steel nozzle does not appear fire damaged. This is considered a

consequence of external fuel or hydraulic fluid falling or spraying on aft end.

An assessment of the cause of the wing overpressure has been made. This

assessment, in conjunction with visual inspection of the damage indicates that an intank explosion occurred which destroyed the integrity of the torque box by separating

the wing panels and spars from their internal support structure. Further damage

occurred after the overpressure due to inertia loads imposed during landing rollout.

The engine separation was found to be due to a maintenance error when reassembling the components of the strut linkages.

Mitigating Action Taken

Procedural changes were implemented at the specific airline to ensure existing

instructions for engine retention hardware installation were properly followed.

4. Date: 31 March 1992 Flight phase: Climb

Aircraft: Boeing 707 Tank type: No 4 wing tank

Location: Near Marseilles, France Fuel type: Jet A

As the aircraft was climbing towards flight level 330, both right engines separated from

the wing. The No.3 inboard pylon fitting fractured and subsequently released the

engine under power which then impacted the No.4 engine causing it to separate also.

The crew succeeded in controlling the aircraft and landed gear and flaps down with the

right wing on fire. The aircraft rolled off the runway to the left of centerline and all crew

members evacuated the aircraft safely and the firemen extinguished the fire.

The trailing edge of the wing was totally burnt in the area between both engines. The

inboard and outboard flaps had completely disappeared, revealing the burnt operating

mechanisms. The inboard aileron was severely damaged. Moreover, the examination

of the inboard wing box identified the marks of an inner explosion on fuel tank No.4.

This explosion seemed to be at the origin of significant deteriorations affecting the wing

stiffness. This explosion had caused the displacement of the inner ribs of this tank.

The wing stiffness was particularly damaged on the front and aft spars. Thus, it

appeared that the right wing was severely damaged first because of a fire and then

because of an inner explosion at the fuel tank No.4.

Note: All right wing valves, transfer and shutoff valves operated normally, when tested.

The shutoff valves were found in the fully closed position and the transfer valves were

found in the open position which matched the cockpit switch positions. The fuel

leakage on the leading edge of the wing near engine No.3 could not have been caused
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Task Group 1 22

by a closing failure of the shutoff valve. Damage (collateral) of the piping following the

pylon detachment could be the cause of the leak. The exact location of the leak could

not be detected.

During all of the descent at speeds greater than 220 kt, it is probable that the fuel leak

carried on without the fuel catching fire, as the conditions for ignition (depression of the

upperwing, speed....) were not achieved and the vaporized fuel was not in contact with

the electrical short-circuits of the damaged cabling loom located on engine No.3 leading

edge. These conditions changed during the last turn as a consequence of the semiextension of the flaps. The speed reduced (between 220 and 190 kt), the depression

on the upper wing decreased and the turbulence increased. Then, it was possible that

under the effect of the electric arcs of the short-circuits quoted above, the fuel ignited,

as the conditions of the kerosene-air mixture became optimal for burning. The fire was

violent as the condition of the upper wing demonstrated, particularly at the trailing edge.

This intense fire had destroyed the trailing edge as well as the flaps and left evidence

of overheating over the whole of aft part of the right fuselage side. The air traffic

controller advised that the right wing was on fire at 08:33:28 hrs and the landing

touchdown occurred at 08:35:35 hrs. Consequently, the right wing fire lasted for at

least two minutes.

The accident report did not provide a good rationale for the explosion in the No.4 main

tank. It is believed that during the intense fire the wing structure may have weakened

and fire progressed to the air-fuel mixture in the tank.

Mitigating Action Taken

An airworthiness directive was issued to inspect the pylon/strut mid-spar fittings at 1500

hours or 600 cycles.

Lightning Strike Events

5. Date: 8 December 1963 Flight phase: Holding

Aircraft: Boeing 707 Tank type: Wing (reserve) tank

Location: Elkton, Maryland Fuel type: Jet A / JP-4 mix

The flight was in a holding pattern at 5,000 feet awaiting an instrument approach to

Philadelphia airport from Baltimore, when it was struck by lightning. Immediately

thereafter, the aircraft was observed to be on fire. A large portion of the left wing

separated in flight and the aircraft crashed in flames near Elkton, Maryland. The

probable cause was lightning induced ignition of the fuel/air mixture in the No.1 reserve

fuel tank with resulting explosive disintegration of the left outer wing and loss of

airplane control.

Fuel onboard at the time of the accident was approximately a 68% Jet A / 32% JP-4 by

volume mix. It was estimated that fuel temperatures were 42°F in the reserve tank and

46°F in the main tanks. Considering all factors it was concluded the fuel vapors in all

tanks were within the flammability limits. Multiple lightning-strike marks were found on

the left wing tip. Although much effort was expended, the physical evidence failed to

disclose the precise mechanism of ignition which triggered the explosion in the left

reserve fuel tank.

Mitigating Action Taken
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Task Group 1 23

A fire suppression system was installed on some airplanes which consisted of a lighttriggered fire extinguishing system in the wing surge tank. Additionally, some airplanes

had a flow-through vent system installed. An FAA Advisory Circular 20-53 was

developed to define lightning strike zones.

Since incorporation of the above design changes and practices, there has not been a

recurrence of a lightning strike event on the 707/720 model.

6. Date: 9 May 1976 Flight phase: Approach

Aircraft: Boeing 747-IIAF Tank type: Wing tank

Location: Madrid Fuel type: Jet A / JP-4 mix

The airplane was being operated as a military logistic flight to McGuire AFB with an

enroute stop at Madrid, Spain. During descent for the approach at 6,000 feet, the

airplane was struck by lightning which resulted in an explosion and separation of the

left wing causing loss of control. Prior to the event, the crew requested ATC vectors

around severe thunderstorm activity. The fuel onboard was a mixture of 58% JP-4 and

42% Jet A type.

At the time of the accident the weather was cloudy with rain and lightning, but good

visibility. At least two witnesses reported seeing lightning strike the airplane. Parts

from the left wing, including a section of the left wing tip, were the first found along the

flight path wreckage.

Evidence of lightning strike, pitting and localized burn areas typical of lightning

attachment were found on the left wing tip and on the vertical fin at the VOR antenna.

The fire centers were located in the wing tip, in the outboard end of No.1 fuel tank, and

the outboard end of No.2 fuel tank. These fire centers were independent and not

interconnected. There was no pattern to the fire, heat, and soot damage in the reserve

tank. In the area of the No.2 tank, the fire, heat, and soot damage pattern on the inner

part of the wing indicated that a fuel fire moved inboard behind the rear spar and along

the trailing edge. At the wing root, the fire pattern extended fore and aft along the

fuselage. The fuel for this fire obviously came from the No.2 tank from which the upper

wing skin cover plank was gone.

Findings and Plausible Hypothesis

The aircraft was fueled with a mixture of JP-4 and Jet A fuels. Lightning struck the

aircraft an instant before an explosion. The first wreckage on the ground contained a

considerable number of parts of the left wing outboard of the No.1 engine. Damage to

the wing in the area of the No.1 fuel tank is the result of a low order explosion. The

ullage of the No.1 tank contained a flammable mixture of fuel and air. Pressures

provided by the ignited fuel were sufficient to cause the damage. Three fires occurred

in No.2 tank, No.1 tank, and the wing tip surge tank. The crushing or collapsing of the

fuel tube in the No.1 tank required an application of pressure only available from an

explosion. The pressure required to detach the stringers and skin from the wing were

in the range of typical pressures developed by an explosion. The first deposit of

wreckage formed a pattern of light objects downwind and heavy objects upwind, which

is not compatible with gusting or turbulent wind conditions but is compatible with an

explosion in calm or steady wind conditions. The H.F. antenna and wing tip edge were

snapped off the wing by inertial loads developed by an oscillating outer wing. The

loosening of the stringer/plank unit from the wing destroyed the aft wing box of the
14 July 1998

Task Group 1 24

wing. Extreme engine oscillations developed as a result of the wing box damage. The

loss of the rear box structure allowed the wing to twist torsionally and to deflect up and

down about the rear spar. The first objects along the flight path were units from the

inside of No.1 fuel tank. The three fire areas within the left wing contained electrical

devices. The highest level of residual magnetic field was along the rear spar aft of the

No.1 tank. A motor that operates a fuel valve normally mounted in this position was

never found. Damage to the fuel tank access doors could only result from pressure

from inside. No structural loads were applied to these doors. The 28Hz oscillations

superimposed on the power line were in the area of the third harmonic of the wing

oscillations (9Hz) which were attributed to engine fan rub in the early service history of

the 747. The inertial damage to the extreme wing tip (H.F. antenna and coupler) could

result only if the inboard section of the wing tip was still attached to inner wing. Throttle

lever vibration in synchronization with the wing oscillations was observed during

previous incidents. The damage to the wing tip cannot be caused by gust loads or

aerodynamic loads. They were due to wing oscillations. The wing oscillations were the

result of rear box failure. The deformation to rib WS 1168 was caused by pressure

loads prior to its departure from the wing along with the jettison fuel line. The flight

control difficulty mentioned on the CVR was probably related to the outer wing damage.

The crossover vent duct for the forward outboard end of the No.1 tank was severely fire

damaged, and the aft end was never recovered.

Fuel Tank Flammability Evaluation Results

Based on these calculations of the fuel and ullage conditions, the fuel/air mixture in

portions of the ullage may be such as to permit ignition at the time of a descent through

10,000 feet.

Analysis

Consensus of the highly specialized investigation team was that an explosion occurred

at or near the aft outboard corner of the No.1 Tank.

Conclusion from the Accident Report

After analyzing all of the available evidence, it is concluded that the most probable

sequence of events which culminated with multiple structural failures and separation of

the wing began with an ignition of the fuel vapors in the No.1 fuel tank. The damage to

the structure in the area of the tank provided positive indications of an explosion. The

possibility that the explosion was a secondary result of an initial structural failure

caused by excessive aerodynamic forces developed during high velocity gusts and

turbulence cannot be completely dismissed; however, the evidence and the

probabilities of an aircraft encountering these unique environmental conditions make

this hypothesis less supportable.

Mitigating Action Taken

A design change was incorporated that basically improved bonding (electrical

grounding) where plumbing passes through the wing spar to further dissipate the

voltage difference.

There has been no recurrence of a lightning strike related explosion to this model

airplane or any other fleet airplane since this event in more than 246 million flights.
14 July 1998

Task Group 1 25

Ground Maintenance Events

7. Date: 17 September 1967 Flight phase: Ground maintenance

Aircraft: Boeing 727 Tank type: Center

Location: Taiwan Fuel type: Jet A

The airplane was undergoing routine scheduled maintenance of the interior of the left

wing tank. Both No.1 (wing) and No.2 (cheek tank) tanks had been drained and were

open. Tank No.1 had been purged and No.2 tank was to be purged. A flash fire

occurred followed in a few seconds by an explosion which ruptured the integral section

comprising the RH end of tank No.2. An 8 ft. by 12 ft. section of upper wing structure

was blown off. A small fire flared up in the damaged area which was quickly put out.

There were 74 people in the immediate area. 16 persons were injured; five of these

received serious injuries.

The precise source of ignition could not be determined. However, the following

information was obtained in the ensuing investigation:

An explosion-proof light was illuminating the interior of the electronics compartment and

was still functioning after the explosion. There was no evidence to indicate that it had

been plugged in coincident with the event. All power was off the airplane, the ground

power unit had been shutdown nearly two hours earlier, and the battery had been

removed.

The lead man in charge of tank purging stated that purging with portable CO2 bottles

had been completed within tank No.1, and that the CO2 equipment had been laid down,

and that the crew had been instructed to open up the RH access door of tank No.2

before purging that tank. No checks had been made of explosive vapor concentration

either internally or externally.

The tank purging procedure used is noted to be contrary to the procedure

recommended in the OEM manual. One of the more severely burned mechanics,

interviewed later in the hospital, was stated to have corroborated the above. The FAA

personnel had come to the conclusion that tank No.2 was being purged through the LH

access opening at the time. They based their assumption on the statement that the

CO2 equipment had just been laid down on a work stand, and that the most seriously

burned mechanic was standing on a stand near the LH No.2 tank, not No.1.

It was noted that metallic parts in the CO2 discharge assembly might produce a spark

and also that the static electricity discharges from the fiber horn or nozzle on portable

CO2 bottles have been historically a cause of fuel fires.

A mechanic was filing a piece of light gage stainless steel, making a nut retainer, in a

wheel well area. Another was making a layout on another piece of metal. The first

man, who received burns on exposed skin areas, reported that he felt pain and ran

from the area. He did not report noting the origin of the explosion.

The only ground leads specifically identified were connected to the RH landing gear,

rather than to the grounding lug provided on a RH gear door, and to the rear fuselage.

Whether or not ground leads were attached to the work stands, as recommended by

the OEM, was not determined due to confused activities following the explosion. A

large crew of workmen were reported to be cleaning (but not polishing i.e., using

buffers or polishing compounds) with cans of solvent, brushes and cloths. After the

explosion, several of the cans of solvent were noted to be on fire. Electrical outlets
14 July 1998

Task Group 1 26

were non-explosion proof; however, none was reported as being used, at the time,

except for the connection to the light in the electrical compartment.

No precautions had been taken to limit access or post warnings in the area. The FAA

considers that any of the 74 men in the area might have created a spark which could

have ignited fumes in the area.

Mitigating Action Taken

The CO2 bottle flow rates were reduce and the discharge nozzles inspected and

reworked. There is no known recurrence of this event for these specific causes.

8. Date: 23 March 1974 Flight phase: Ground maintenance

Aircraft: McDonnell Douglas DC-8 Tank type: Wing

Location: Travis AFB, California Fuel type: JP-4

Upon arrival at Travis Air Force Base from a Military Charter flight, a routine

maintenance “A” check was being accomplished including maintenance action in

response to the flight crew reports of inflight mechanical irregularities that appeared on

the previous two flight legs. One of the crew log reports was an inoperative No.1 fuel

boost pump.

Access to the boost pump was made through the top of the wing. This was done by

removing the No.1 main fuel tank access cover, located behind and slightly outboard of

the number 2 engine pylon. Affected circuit breakers for the fuel system had been

opened. The tank contained approximately 3,000 pounds of JP-4 fuel. The boost

pump was partially submerged in fuel. The total fuel on the aircraft was 25,000

pounds. External power from a ground power unit was connected to the aircraft.

Removal and re-installation of a different boost pump was completed. An operational

check of the pump was then attempted and failed. Two of three circuit breakers for the

AC three phase pump opened and no boost pressure was noted. It is noteworthy that

the same two circuit breakers had opened while enroute on a prior flight leg which

resulted in a log book write up “No.1 main boost pump inop”. Maintenance replaced

the fuel boost pump with the second pump to see if the malfunction could be cleared.

Electrical power from an external power unit was reconnected after a “low fuel” warning

signal was activated. Inspection of the newly installed fuel boost pump electrical

connector was conducted.

At 2008 PDT an explosion occurred in the left wing center section. The upper wing

surface between nos. 1 and 2 engines was blown forward and away from the airplane

centerline some 250 feet from the airplane. A fire then began which engulfed the entire

left wing, fuselage, and inboard right wing. Evidence from the recovered fuel boost

pumps and connectors revealed no evidence of burning. The explosion resulted in hull

loss, and one fatality.

The investigation also points to an external ground power unit that was supplying power

to the aircraft while tank maintenance was being performed. It also mentions a

flashlight which one of the mechanics on the wing had in his possession which had a

broken “flasher” switch i.e. the switch that allows the user to momentarily activate the

light without locking it on or off. Most of the recommendations from everyone involved

focused on procedures to prevent another accident. No conclusive evidence of an

ignition source was established.

Mitigating Action Taken
14 July 1998

Task Group 1 27

The mitigation action taken for this event has yet to be determined.

Refuelling Events

9. Date: 3 May 1970 Flight phase: Refuelling

Aircraft: Boeing 727 Tank type: Center

Location: Minneapolis Fuel type: Jet A

The airplane was being refuelled using a single-point refuelling system. About 2,000

lbs of fuel had been loaded when a heavy muffled explosion occurred in the No.2

(cheek tank). A puff of gray smoke came from the LH wing tip vent. Fuelling was

immediately terminated, all electrical power on the airplane was cut off, the APU was

shutdown, and the aircraft was de-fuelled.

No injuries had occurred. No damage was apparent from an external check of the

aircraft. The damage was largely confined to the secondary structure within the No.2

tank on the LH side of the airplane. When inspecting the tank, it was found that the

structure above the top level of the fuel was heavily soot blackened. The ribs visible

from the front spar access hole exhibited heavy deflection and distortion and the

stringers were also damaged. Some pulled rivets were noticeable in the LH wing. The

formed covers for the fuel boost pump were “hydro-pressed” down over both the RH

and LH pumps, but no leaks had developed.

No faults in the electrical systems of the aircraft in and around tank No.2 were found. It

is presumed, in the absence of any electrical sources, that ignition resulted from a static

discharge within the No.2 tank.

Time of day was 8:28 am. Fuel temperature was 55°F. Flash point of samples was:

Tank #1-118°F, Tank #2 - 120°F, Tank #3 - 110°F and the Storage tank from which

the fuel was loaded was 127°F.

At the time of the event the following airplane systems were operating; the APU was

operating and the LH pack was on to heat the cabin, All navigation lights on. No boost

pumps were on.

The duration of the fuelling was approximately 5 minutes with the No.2 tank 31% full.

Mitigating Action Taken

No mitigating action taken since no root cause for an ignition source was found.

10. Date: 23 December 1970 Flight phase: Refuelling

Aircraft: Boeing 727 Tank type: Center

Location: Minneapolis Fuel type: Jet A

The airplane was being refuelled using under-wing refuelling at the RH wing station.

Approximately 3,000 pounds of fuel had been loaded when a muffled explosion was

heard. Fuelling was immediately stopped and a minor leak was noticed coming from

the area of the inboard boost pump in the LH wing. There was no fire and no injuries to
14 July 1998

Task Group 1 28

any of the servicing personnel. Over-pressure damage to the aircraft’s No.2 fuel tank

was extensive but minor in nature.

The aircraft was being readied for its next departure. Besides the refuelling operations,

other activity around the aircraft included baggage loading and de-icing operations.

Some light snow was being stirred around by a wind that was blowing from the left to

the right wing at 18 knots with gusts to 24 knots. The outside ambient temperature was

+8°F.

After about 5 minutes of fuelling with kerosene type A (Jet A) , a harsh muffled

explosion shook the aircraft with a large white cloud of smoke or vapor issuing from the

LH wing root area and continuing for about 30 seconds. The outboard boost pump

cavity access door was split in two with half flying across the apron and half still

dangling from the opening. Fuel was leaking from the cavity area in a stream about the

size of a pencil diameter. The fueller immediately dropped the “dead man” switch and

closed both fuelling nozzles. The fire department was then summoned, and they hosed

down the area.

Subsequent examination of the aircraft revealed minor exterior physical damage, most

noticeable being the blown-off access door, collapsed and fractured number 2 tank LH

fuel boost pump cavity housing, and popped rivet heads on the number 2 tank LH

upper skin area. Interior physical damage was quite extensive within the number 2 fuel

tank. Both the No.1 and No.3 tanks were undamaged. Evidence of soot deposits were

found within the left and right hand surge tanks, the number 2 fuel tank, and at each

wing tip fuel tank vent scoop area.

The investigation that followed the incident indicated that the probable cause of the

explosion was delivery by the ground fuelling system of highly charged fuel into the

airplane. However, the investigation was unable to pinpoint the exact source of ignition

that triggered the combustion of the fuel vapor. The evidence is very strong, however,

that the source of ignition was static discharge internal to the number 2 fuel tank.

Time of day was 6:18 am. Fuel temperature was 31°F. Flash point of samples was:

Tank #1-119°F, Tank #2 - 118°F, Tank #3 - 124°F and the Storage tank from which

the fuel was loaded was 121°F.

At the time of the event the following airplane systems were operating: APU, all

navigation lights on, No.2 tank boost pumps on and all crossfeed valves open.

The duration of the fuelling was approximately 5 minutes with No.2 tank 32% full.

Mitigating Action Taken

The paper element filter separators in the ground refuelling equipment were replaced

with filters that did not create electrostatic charging.

The has been no recurrence of a refuelling related event to this model since changes

were made.
14 July 1998

Task Group 1 29

11. Date: 21 June 1973 Flight phase: Refuelling

Aircraft: McDonnell Douglas DC-8 Tank type: Wing

Location: Toronto Fuel type: JP-4 / Jet A mix

The airplane was at the gate and a ground power unit was connected to the airplane’s

electrical system when a fuel tank explosion blew off pieces of the right wing top skin

and spar structure. Burning fuel rapidly engulfed the right wing. The aircraft was

destroyed and two ramp servicing personnel were seriously burned.

The aircraft was being fuelled with Jet B (JP-4), but examination of the left wing tanks

revealed a fairly even mix of Jet A-1 and Jet B. Some Jet A-1 was already in the tanks.

The ambient temperature was 76°F.

Shortly thereafter an explosion occurred in the right wing. A 20 foot long piece of wing

upper skin covering the forward portion of number 3 alternate and number 4 main tank

was blown high into the air and landed about 100 feet to the right of the aircraft.

Flames erupted from the right wing and burning fuel was sprayed onto a man on a

conveyor who leaped off toward the rear of the aircraft. This explosion was followed

almost immediately by another which blew a 10 foot long piece of the upper wing skin

from the aft section of the number 3 alternate tank to a position forward and to the left

of the aircraft. The loss of this skin allowed the right wing to collapse, hinging from the

bottom skin. Burning fuel ran from the ruptured number 4 tank and fuel manifold over

the leading and trailing edges of the wing. The fueller under the right wing ran toward

the front of the aircraft through the fire that now extended to the ground and he was

doused with burning fuel. Both the refueller and the cargo handler were seriously

burned. No passengers had boarded the aircraft. The nine crew members aboard

evacuated through the loading bridge.

The findings of the Canadian Department of Transportation were that the initial

explosion occurred in the number 3 alternate tank and that the fuel vapor was ignited in

the wing vent system. The source of ignition of fuel vapor in the wing tank vent system

could not be definitely determined, but was suspected to have originated outside the

aircraft.

Mitigating Action Taken

It is believed that no direct action was taken since it appeared that ignition of the fuel

vapor had taken place outside the aircraft adjacent to the vent outlet.

12. Date: 6 June 1989 Flight phase: Refuelling

Aircraft: Beechjet 400 Tank type: Aux Tank

Location: Washington D.C. Fuel type: JP-4 / Jet A mix

The aircraft departed early in the morning from Jackson, Mississippi enroute to New

Orleans. Early in the afternoon the airplane returned to Jackson and was refuelled with

JP-4. At approximately 4:00 p.m. CST the airplane departed from Jackson enroute to

National Airport in Washington, DC After arrival in Washington, the crew spent

approximately one hour securing the airplane before departing for the hotel. Line

service then began refuelling operations. Operations manager advised that the fuel

truck was grounded to the airplane and also to the fuel ramp grounding point. Main

wings were topped off first with Jet A fuel. Line personnel then began to service the aft

tanks. Prior to service, there was approximately 200 pounds of fuel remaining in the
14 July 1998

Task Group 1 30

tanks. After pumping five gallons into the aft tank through the aft filler port, line

personnel reported hearing a hissing noise followed by a bang. Fuel surged out of the

filler opening and covered the line service personnel. At this point, refuelling was

terminated and the pilots were contacted. At the time of refuelling there were

thunderstorms in the area at the time of refuelling. Shortly after the refuelling

operations began, heavy rain began falling in the area of the airport.

Fuel was later noted dripping from the underside of the airplane. After the cabin interior

seats were removed to gain access to the aft fuel tank, it was found to be torn loose

from all 14 fuselage attach points. The tank had expanded significantly from internal

pressure. The forward access panels on the tank were removed for internal viewing.

The inside of the tank exhibited very heavy carbon deposits throughout the tank and

especially on the upper surface of the horizontal support frames within the tank. These

deposits indicate some type of fire or detonation occurred inside the tank.

The investigation concluded the most probable cause was that during refuelling of the

interconnected fuselage and auxiliary tanks, an electrostatic discharge occurred which

resulted from charged fuel entering the aft auxiliary tank from the fuselage tank. The

fuselage mounted tank had a blue foam installed in the tank to protect against rotor

burst threats. The foam being used at the time was determined to have low

conductivity characteristics and was able to build up an electrostatic charge which

subsequently discharged in the aft tank that did not have the protective foam installed.

Mitigating Action Taken

Final action resulted in an airworthiness directive to replace the blue foam with a more

conductive foam and install additional bonding and grounding to the subject fuel tank.

Other - Parked in Hanger

13. Date: 2 June 1982 Flight phase: Parked

Aircraft: McDonnell Douglas DC-9 Tank type: Fwd Aux Tank

Location: Montreal Fuel type: Jet A-1

While the airplane was parked in the hangar, it is believed that a fuel boost pump

located in the forward auxiliary fuel tank had been left on and overheated, causing an

over-pressure in the (de-fuelled) tank, and a subsequent fire which destroyed the

aircraft. Structural analysis of the auxiliary tank did not show signs of an “explosion”

but did show signs of rapid over-pressure in the tank. The residual fuel in the forward

auxiliary fuel tank (estimated at 2.6-3 US gallons) was insufficient for pump priming;

therefore there was no motor cooling which resulted in excessive fuel vapor generation

within the tank. The exact source of ignition could not be determined during the

investigation but out of the four electrically operated components in the auxiliary tank,

three could be ruled out as spark producing agents. These are: the fuel quantity

probes and the float switch which were not energized and the fuel pressure switch

which was found in good condition and its electrical wiring is installed in a metal tube.

The fourth item, the transfer pump power supply harness, is the most probable source

of sparks. Examination of electrical assemblies on other aircraft indicated burned

sockets and pins at the pump connector. The burn marks were the result of arcing. If a

faulty connector has a secondary failure at the harness pressure seal, a spark could

ignite a critical fuel vapor/air mixture. Considered a serious over-pressure event.
14 July 1998

Task Group 1 31

Mitigating Action Taken

No aircraft-related action was taken since this was treated as an industrial accident

rather than an event affecting airworthiness.

14. Date: 11 May 1990 Flight phase: Climb

Aircraft: Boeing 727-100 Tank type: Center tank

Location: Bogota, Colombia Fuel type: Jet A

The airplane was climbing through 10,000 feet when an explosion occurred.

Investigator reports discovered evidence of a bomb explosion. Close

examination of the aircraft structure revealed evidence on the RH side of the

passenger cabin between the emergency overwing exits. The evidence

indicated the force generated by the blast compromised the structural integrity in

this area causing a fuel tank rupture, fire, and inflight structural breakup of the

right wing. The local ambient temperature reported at the airport was 52°F.

Cause Unknown

15. Date: 11 May 1990 Flight phase: Parked / Push Back

Aircraft: Boeing 737-300 Tank type: Center tank

Location: Manila, Philippines Fuel type: Jet A

While being pushed back from the gate, the center tank exploded and burned. At the

time of the explosion, the engines were not running and the aircraft electrical power

and air-conditioning were supplied by the Auxiliary Power Unit (APU). Preliminary

evidence indicates that ignition of the fuel-air mixture in the center fuel tanks was the

cause of the explosion and subsequent fire. The investigation focused on the center

fuel tank, which was determined to be the source of the explosion, and the possibility of

an explosive or incendiary device, an external source of ignition or mechanical and/or

electrical failure as a source of ignition. The investigation found no evidence of a

bomb, an incendiary device, or sabotage. The investigation has yet to reveal the exact

ignition source.

At the time of the accident, all the fuel boost pumps were in the “on” position. The

center fuel tank had not been filled since 9th March 1990. During the pushback of the

airplane the center fuel tank low pressure light illuminated, indicating that the center

fuel tank had been emptied of all usable fuel. Laboratory examination of the fuel

samples from the airplane and fuel storage tanks indicates that the fuel vapor in the

center tank would have had a flash point of between 112 - 117°F. The ambient

temperature at the time of the accident was 95°F. The fuel was estimated to be

approximately 115°F based on samples of fuel drawn from other similar airplanes

following the incident. It was estimated that approximately 90 pounds of fuel was in the

center tank.
14 July 1998

Task Group 1 32

Of the 114 passengers and six crew members, eight were fatally injured and 30

sustained injuries.

Mitigating Action Taken

Boeing published an all operators bulletin reminding flight crews to not operate the

center boost pumps when no usable fuel was available in center tank.

16. Date: 17 July 1996 Flight phase: Climb

Aircraft: Boeing 747-100 Tank type: Center tank

Location: New York Fuel type: Jet A

The airplane was climbing near 13,800 feet (msl) when an inflight explosion occurred in

the center wing fuel tank approximately 13 minutes after takeoff, resulting in loss of

structural integrity inflight. The center wing tank was estimated to contain

approximately 100 gallons of fuel. Prior to dispatch of the airplane, the air-conditioning

air cycle machines, located under the center wing tank, had been operating for up to 2

hours. The center wing tank estimated fuel temperatures was 113-115°F. At the

altitude and temperatures of the event, the fuel tank air/vapor mixtures were considered

to be flammable. The fuel type was Jet A. There were 230 fatal injuries including the

flight crew.

Mitigating Action Taken

A series of service bulletins have been issued against the B-747 series, covering fuel

pump electrical installation inspections, addition of a scavenge pump flame arrestor,

and inspections and replacements of FQIS wiring and probes.

For the B-737 series (which has a similar fuel system), bulletins covering fuel tank

system component and wiring inspections, and flame arrestors in the vent system are

being incorporated.
Explosion Suppression

Task Group 2

Aviation Rulemaking Advisory

Committee ARAC

JA

A

FA

A

THE PUBLIC
24 June 1998

EXPLOSION SUPPRESSION

ARAC Fuel Tank Harmonization Working Group,

Task Group 2

Terry L. Reddout, Bombardier Learjet Chairman

Etienne Foch, Aerospatiale Member

Wade P. Young, United Parcel Service Member

William L. Vannice, Boeing Member

June 1998

July 1998
24 June 1998

Task Group 2: Explosion Suppression

Page 1

1. Abstract:

HARMONIZATION TERMS OF REFERENCE

TITLE OF INITIATIVE: PREVENTION OF FUEL TANK EXPLOSIONS

Background: The cause of TWA800 747 accident has been attributed to a fuel tank explosion within the

center wing fuel tank (CWT). The source of ignition of the explosion is believed to be within the fuel tank,

however no conclusive ignition source has been found by accident investigators. The National

Transportation Safety Board has concluded from the accident investigation that an explosive mixture of

fuel-air vapors existed in the empty CWT of TWA800. The presence of explosive mixtures in the tank is

exacerbated by heating of the residual fuel in the tank due to the location of the air conditioning equipment

below the CWT.

The FAA has identified 10 transport airplane hull loss events since 1959 which were attributed to fuel tank

explosions. The investigation of TWA800 and the number of fuel tank explosions which have occurred in

service have led the FAA to question the adequacy of transport airplane certification requirements relative

to fuel tank design, specifically with respect to environmental considerations and the adequacy of steps to

minimize the hazard due to potential of ignition sources, both in initial design and over the life of the

airplanes.

Based on its preliminary study, the FAA believes several approaches to improve fuel tank explosion safety

have potential for implementation in the commercial airplane fleet and, therefore, warrant further detailed

study. The first is minimization of hazard due to explosive fuel system conditions by mandating certain

design and maintenance practices. The second is prevention of the occurrence of a flammable fuel/air

mixture in the tanks through some means of inerting, or modified fuel properties such as JP-5. The third

means includes mitigation of the hazards of a fuel tank explosion through installation of polyurethane foam

or fire suppression systems. The FAA published a notice on April 3, 1997, requesting public comment on

the proposed NTSB recommendations. Cost benefit data provided by commenters was inconsistent and in

many cases no justification for the data was provided. A significant amount of data has been collected and

must be evaluated. The FAA has determined that amendment to the Federal Aviation Regulations

concerning fuel tank flammability may be necessary.

The following task should provide the basis for the FAA and JAA to determine what regulatory action

should be taken to increase the level of safety of the existing fleet, current production airplanes, and new

type designs to address the fuel tank explosion threat.

SPECIFIC TASK:

Prepare a report to the FAA/JAA that provides specific recommendations and proposed regulatory text, that

will eliminate or significantly reduce the hazards associated with explosive vapors in transport category

airplane fuel tanks. Proposed regulatory text should ensure that new type designs, in-production airplanes

and the existing fleet of transport airplanes are designed and operated so that during normal operation (up

to maximum certified operating temperatures) the presence of explosive fuel air vapors in all fuel tanks is

eliminated, significantly reduced or controlled to the extent that there could not be a catastrophic event.

(This task addresses means of reducing explosion hazards by eliminating or controlling explosive vapors.

The FAA is also engaged in a separate activity to evaluate whether additional actions should be taken to

ensure that ignition sources are not present within the fuel tanks. Therefore, control of ignition sources are

not within the scope of this task.) In developing recommendations to the authorities, a report should be

generated that includes the following:

1) An analysis of the threat of fuel tank explosion due to internal and external tank ignition sources for

the major fuel system designs making up the transport fleet, including transport airplanes with heat

sources adjacent to or within the fuel tanks. The SAFER data presented to the FAA in 1978, which

includes evaluation of fuel tank safety in both operational and post crash conditions, should be used

as a starting point for determining the level of safety.

2) An analysis of various means of reducing or eliminating exposure to operation of transport airplane

fuel tanks with explosive fuel air mixtures (e.g., inerting, cooling of lower center tank surfaces,
24 June 1998

Task Group 2: Explosion Suppression

Page 2

combination of cooling and modified fuel properties, etc.) or eliminating the resultant hazard if

ignition does occur (installation of selective/voided/full tank reticulating foam, explosion suppression

systems). Technical discussion of the feasibility, including cost/benefit analysis, of implementing

each of the options on a fleet retrofit, current production, and new type design airplanes should be

provided.

3) An analysis of the cost/benefit of modified fuel properties that reduce exposure to explosive vapors

within fuel tanks. The FAA has asked industry through the American Petroleum Institute to provide

pertinent information on fuel properties. The degree of modification to fuel properties necessary to

eliminate or significantly reduce exposure to explosive fuel tank ullage spaces in fleet operation must

be determined by the group. Factors that may enhance the benefits of modified fuels, such as cooling

provisions incorporated to reduce fuel tank temperatures should be considered. Cost information for

the various options should be developed, such as engine air/ground starting at low temperatures,

maintenance impact, emissions and fuel freeze point, should be analyzed by the group and be

provided.

4) Review comments to the April 3, 1997, Federal Register Notice and any additional information such

that validated cost benefit data of a certifiable system is provided for the various options proposed by

commenters. This information will be used in preparing regulatory action.

Note: In many cases specific cost data provided in the comments to the notice was competition

sensitive, therefore the ARAC group should contact commenters directly and request participation

in the group.

5) Recommend objective regulatory actions that will eliminate, significantly reduce or control the

hazards associated with explosive fuel air mixtures in all transport airplane fuel tanks to the extent

that there could not be a catastrophic event.

In addition to the above tasks, support the FAA in evaluation of application of the proposed regulation to

the various types of transport airplanes (turbo-propeller, business jets, large transports, and other turbinepowered aircraft types which may be affected by a change in fuel properties/availability) and any impact on

small businesses.

This activity will be tasked for a 6 month time limit to complete the tasks defined above. The FAA will

consider the recommendations produced by ARAC and initiate future FAA regulatory action. However, if

the group is unable to provide the FAA with proposed regulatory language within this time period the FAA

will initiate rulemaking independently. Participants of the ARAC should be prepared to participate on

a full time basis for a 6 month period if necessary.

PROPOSED HWG ASSIGNMENT: We recommend that this project be managed by a new Fuel Tank

Harmonization Working Group (FTHWG), that would report directly to the ARAC Executive Committee.
24 June 1998

Task Group 2: Explosion Suppression

Page 3

2. Table of Contents:

Section Subject Page

1. Abstract .......................................................................................................................1

2. Table of Contents.........................................................................................................3

3. Introduction..................................................................................................................5

4. Summary......................................................................................................................6

4.1. Discussion....................................................................................................................6

4.2. Conclusions.................................................................................................................7

5. References....................................................................................................................9

5.1. Documents...................................................................................................................9

5.2. Interviews ....................................................................................................................10

6. Background..................................................................................................................11

6.1. Active Explosion Suppression: .....................................................................................11

6.1.1. Optical Detector System ...............................................................................................11

6.1.2. Control Unit / Power Supply System.............................................................................11

6.1.3. Suppressant System......................................................................................................11

6.2. Why Military uses this Technology...............................................................................12

6.3. Military Service Experience and History with this technology .......................................12

7. Design Alternatives......................................................................................................12

8. Design & Installation Requirements..............................................................................13

8.1. Optical Detector System ...............................................................................................13

8.1.1. Design..........................................................................................................................13

8.1.1.1. Thermal Detectors........................................................................................................13

8.1.1.2. Photon Detectors..........................................................................................................13

8.1.2. Installation ...................................................................................................................13

8.2. Control Unit / Power Supply Systems...........................................................................14

8.2.1. Design..........................................................................................................................14

8.2.2. Installation ...................................................................................................................14

8.3. Suppressor Systems......................................................................................................14

8.3.1. Design..........................................................................................................................14

8.3.1.1. Suppressant..................................................................................................................15

8.3.1.2. Suppression System Container......................................................................................15

8.3.2. Installation ...................................................................................................................15

9. Technical Data .............................................................................................................16

9.1. Kidde Aerospace and Defense ....................................................................................16

9.1.1. Kidde Technical Data ...................................................................................................16

9.1.1.1. Weight .........................................................................................................................16

9.1.1.2. Size (cargo/passengers/fuel displaced) ..........................................................................16

9.1.1.3. Range Impact ...............................................................................................................16

9.1.2. Certifiability status.......................................................................................................17

9.1.2.1. Similarity to previous tests or flight experience .............................................................17

9.1.2.2. Additional Testing or Analysis......................................................................................17

9.1.2.3. Other Effects on the Aircraft.........................................................................................17

9.1.3. Safety...........................................................................................................................17

9.1.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)..........................17

9.1.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events.......................17

9.1.3.3. Negative Impacts..........................................................................................................17

9.1.4. Cost Impact..................................................................................................................19

9.1.4.1. Component Costs and Standard Aircraft Matrix Summary.............................................19

9.1.4.2. Retrofit.........................................................................................................................19

9.1.4.3. Current Aircraft (Production Incorporation and Continued Production) .........................20

9.1.4.4. New Aircraft ................................................................................................................21

Table 9.1. Kidde - Explosion Suppression System.......................................................22

9.2. Pacific Scientific / HTL...............................................................................................23

9.2.1. Pacific Scientific / HTL Technical Data ........................................................................23

9.2.1.1. Weight .........................................................................................................................23
24 June 1998

Task Group 2: Explosion Suppression

Page 4

9.2.1.2. Size (cargo/passengers/fuel displaced) ..........................................................................23

9.2.1.3. Range Impact ...............................................................................................................23

9.2.2. Certifiability status.......................................................................................................23

9.2.2.1. Similarity to previous tests or flight experience .............................................................23

9.2.2.2. Additional Testing or Analysis......................................................................................24

9.2.2.3. Other Effects on the Aircraft.........................................................................................24

9.2.3. Safety...........................................................................................................................24

9.2.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)..........................24

9.2.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events.......................24

9.2.3.3. Negative Impacts..........................................................................................................24

9.2.4. Cost Impact..................................................................................................................25

9.2.4.1. Component Costs and Standard Aircraft Matrix Summary.............................................25

9.2.4.2. Retrofit.........................................................................................................................25

9.2.4.3. Current Aircraft (Production Incorporation and Continued Production) .........................25

9.2.4.4. New Aircraft ................................................................................................................25

9.3. Primex Aerospace Company ......................................................................................25

9.3.1. Primex Aerospace Company Technical Data.................................................................25

9.3.1.1. Weight .........................................................................................................................27

9.3.1.2. Size (cargo/passengers/fuel displaced) ..........................................................................27

9.3.1.3. Range Impact ...............................................................................................................28

9.3.2. Certifiability status.......................................................................................................28

9.3.2.1. Similarity to previous tests or flight experience .............................................................28

9.3.2.2. Additional Testing or Analysis......................................................................................28

9.3.2.3. Other Effects on the Aircraft.........................................................................................28

9.3.3. Safety...........................................................................................................................28

9.3.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)..........................28

9.3.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events.......................28

9.3.3.3. Negative Impacts..........................................................................................................29

9.3.4. Cost Impact..................................................................................................................29

9.3.4.1. Component Costs and Standard Aircraft Matrix Summary.............................................29

9.3.4.2. Retrofit.........................................................................................................................29

9.3.4.3. Current Aircraft (Production Incorporation and Continued Production) .........................29

9.3.4.4. New Aircraft ................................................................................................................29

Table 9.3. Primex - Solid Propellant Gas Generator Systems.......................................30

9.4. Whittaker Safety Systems ..........................................................................................31

9.4.1. Whittaker Safety Systems Technical Data .....................................................................31

9.4.1.1. Weight .........................................................................................................................31

9.4.1.2. Size (cargo/passengers/fuel displaced) ..........................................................................31

9.4.1.3. Range Impact ...............................................................................................................31

9.4.2. Certifiability status.......................................................................................................31

9.4.2.1. Similarity to previous tests or flight experience .............................................................31

9.4.2.2. Additional Testing or Analysis......................................................................................31

9.4.2.3. Other Effects on the Aircraft.........................................................................................32

9.4.3. Safety...........................................................................................................................32

9.4.3.1. Effectiveness in preventing over-pressure hazard(from the explosion)...........................32

9.4.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events.......................32

9.4.3.3. Negative Impacts..........................................................................................................32

9.4.4. Cost Impact..................................................................................................................33

9.4.4.1. Component Costs and Standard Aircraft Matrix Summary.............................................33

9.4.4.2. Retrofit.........................................................................................................................33

9.4.4.3. Current Aircraft (Production Incorporation and Continued Production) .........................33

9.4.4.4. New Aircraft ................................................................................................................33

Table 9.4. Whittaker Safety Systems - LFE® Suppressant Systems ..............................34

10. Other Supporting Data..................................................................................................35

10.1. Standard Aircraft Matrix...............................................................................................35

3. Introduction:
24 June 1998

Task Group 2: Explosion Suppression

Page 5

The assigned efforts of the ARAC Fuel Tank Harmonization Working Group were divided into eight

separate tasks, each then assigned to individual Task Groups to conduct the associated investigations and

analyses. Each Task Group is staffed by individuals from the various industry, business and professional

interests. These assignments are:

Task Group 1: Service History/Fuel Tank Safety Level Assessment

Task Group 2: Explosion Suppression

Task Group 3: Fuel Tank Inerting

Task Group 4: Fuel Tank Selective/Voided/Full Tank Reticulating Foams

Task Group 5: Tank cooling/Ullage sweeping

Task Group 6: Fuel Properties and Its Effect on Aircraft and Its Operation

Task Group 7: Fuel Properties and Its Effect on Infrastructure

Task Group 8: Evaluation Standards and Proposed Regulatory Action Advisory Group

For the purposes of identifying the spectrum of aircraft being considered and the characteristics of these

aircraft relative to size, operations and environment, a matrix of Standard Aircraft was prepared by Task

Group 8 . This matrix is designed to ‘bracket’ the fleet of existing aircraft, with the exception of the

smaller transport aircraft, like those at the lower end of the bizjet group, and provide generic

representatives upon which the task groups would conduct their analyses. In addition, Task Group 1’s

review of the service and incident history, supported by the temperature studies conducted by Task Group

5, identified the environmental differences between wing tanks and center wing tanks (CWT), especially

CWTs with external heat sources. It was then proposed and accepted that the specific case of the 747 CWT

be included as an additional configuration in each group’s analyses. The Standard Aircraft Matrix is

included in Section 10., Other Supporting Data.

This report documents the activities and findings of Task Group 2, which has the assignment of researching

the industry for existing technologies and systems specifically designed to actively monitor, detect, react to

and suppress an explosion event before the event can produce catastrophic results, by such means as

temperature, structural over-pressure, etc. For the purposes of the Fuel Tank Harmonization Working

Group and the assigned reporting, this form of suppression is specifically and distinctly different than fuel

tank inerting systems or passive void filling foam systems.

The members of Task Group 2 have performed a search for reference material and documents concerning

systems that have been specifically designed to suppress or extinguish an explosion within a fuel tank.

This search began with the questions to the Department of Transportation and the Department of Defense,

and then to vendors known to be involved with such systems. Through this search and questions of the

committee’s membership at large, it was quickly discovered that a great amount of research had been

accomplished in this arena concerning military operations and the need to protect combat aircraft from

external threats where fuel ignition could result, such as ballistic impacts of High Energy Incendiary (HEI)

and Armor Piercing Incendiary (API) projectiles.

From actual live-firing tests and system performance bench tests conducted at the Naval Weapons Center at

China Lake, California, and the Flight Dynamics Laboratory at Wright-Patterson Air Force Base, Dayton,

Ohio, a number of systems have been identified as having demonstrated positive results in providing fuel

tank and dry bay protection from fuel vapor explosions. The applicable technologies center around four

separate methods of dispersing the suppressant

TM Inert Gas Generators

TM Gas Generator driven Agent Dispersal

TM Explosive Expulsion of Low Pressure Agent

TM Explosive Release of High Pressure Agent

Research and test information was received from the Joint Technical Coordinating Group on Aircraft

Survivability (JTCG/AS), Air Force Wright Aeronautical Laboratories, Survivability/Vulnerability

Information Analysis Center (SURVIAC), and the National Institute of Standards and Technology (NIST).

A bibliography of these documents are listed in Section 5., References.
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From these contacts, a list of companies involved in this technology was generated. All of the companies

identified were contacted and were provided a questionnaire and invitation for face-to-face discussion

meetings with Task Group 2. From those contacts, detailed technical information was received from

TM Kidde Aerospace and Defense (including Graviner and Fenwal Safety Systems),

TM Meggitt Electronics (formerly ARMTEC, Detection Systems) ,

TM Pacific Scientific / HTL,

TM Primex Aerospace Company (including the former Olin Aerospace Co.), and

TM Whittaker Safety Systems.

Of these five, each company with the exception of Meggitt, met with task group members to discuss their

particular systems and capabilities.

4. Summary:

4.1. Discussion:

The Kidde Aerospace systems have operational roots in the military. Originally produced by

Graviner, the system provided in tank, wet-bay protection using an IR optical sensor, a low vapor

pressure suppressant, Pentane, and a small explosive charge to rupture the storage container and

throw the suppressant out into the space surrounding the container. This system was placed in

service on a number of British military aircraft and has been documented as functioning

satisfactorily and being credited with a number of ‘saves’ (suppressant discharges associated with

actual ignition threats), though plagued with a large number of ‘false alarms’. These aircraft were

phased out of service in the late 1970’s and early 1980’s, and the suppression systems along with

them.

In developing this system, a number of suppressants were evaluated and Pentane and Halon 1101

were the two found to be superior suppressants. Halon was rejected due to its high vapor pressure

and need for a pressurized container, leaving Pentane as the suppressant of choice for suppression

of explosions within an enclosed fuel tank. On the other hand, the post-crash considerations and

the likelihood of a fuel tank being ruptured during the crash, leave Pentane as a very undesirable

and questionable suppressant.

Pacific Scientific / HTL produce a line of fire extinguishing products, specifically for dry-bays and

classically defined fire zones, and a line of explosion suppressors specifically designed to protect

the occupied compartments of military armored ground vehicles against an external projectile

threat and secondary, internal explosions. The occupied compartment explosion suppression

system utilizes a three-frequency optical sensor, a non-microprocessor controller and solenoid

opened suppressant bottles, specifically tailored to maintain a survivable atmosphere after

discharge.

For the F22 dry-bay protection scheme, Pacific Scientific designed stand-alone sensor-bottle

combinations that can react more quickly than their standard extinguishing technology. This

system incorporates multiple ‘bottles’, using Halon 1301, to provide appropriate coverage.

None of the Pacific Scientific components or systems have been tested in a wet-bay, and

knowingly need a significant amount of additional development and testing to provide adequate

protection in this environment. For a complex aircraft fuel system, additional development for

alternate, more suitable suppressants, and microprocessor controllers to deal with multiple bottle

arrays and variations in ullage volume must be conducted (to minimize any over-pressure hazard).

Primex Aerospace developed a line of solid propellant gas generators, based in the automotive air

bag industry, and extending into dry-bay explosion suppression. These systems produce gaseous

carbon dioxide, nitrogen and water, which can be used directly as a suppressant, or can

The latter of these systems, as with the others, was developed around the military needs for aircraft

protection against the external, incendiary projectile threat. Company and military tests at China
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Lake have shown successful ullage protection with response times quick enough to suppress an

explosion. Though emersed applications still need to be evaluated and qualified, the technology

appears to have a lower sensitivity to variations in ullage volume than a typical Halon suppressant

release. Development testing is still necessary to characterize a gas generator system that is

compatible with today’s aircraft and their requirements.

Whittaker Safety Systems produce a line of fire safety equipment and gas analyzers. In the mid

1980’s, they developed, against a military RFP, a dry-bay explosion suppression system based on

their fire extinguishing technology, but specifically aimed at the wide area dispersal and quick

response needed. Later development of this system utilizes Halon 1301 in a long tube and

released by a shaped charge attached to the tube wall axially, and dubbed the linear fire

extinguisher, LFE®. A dual-spectrum optical sensor detects fuel ignition and the controller reacts

by triggering is a small explosive initiator, mounted outside the fuel bay, which ignites the shaped

charge attached to the storage tube.

Testing was successful against the normal range of external threats and was the first system to

demonstrate any protection against the 30mm high energy incendiary (HEI) threat.

This system was bid, against Kidde’s proposal, for the military P-7A program, as a wet-bay, ullage

protection system. Testing has shown this technology to be very effective, with the shortest

reaction times of any investigated, but further development is necessary to define a system that is

adequately compatible with the closed fuel tank and variations in ullage volume.

4.2. Conclusions:

From the review of the technologies produced by the companies listed above, it is evident that the

technology exists and is effective in suppressing the pressure effects of an explosion before those

effects can become hazardous to the tank enclosure / structure.

a) Optical sensors have been developed to discriminate between the actual ignition of

the hydrocarbon fuel and an extensive number of common and potential light

sources.

b) Microprocessor controls have been developed to a level that reliable and explicit

decisions can be made within the requisite times. A dedicated controller logic will

still be necessary for each specific aircraft installation.

c) Dispersal systems are adequate to provide rapid distribution and suitable

concentrations of suppressants.

d) Installations on new aircraft as well as retrofit of existing aircraft appear to be within

the capabilities of the technology investigated.

It is evident that this technology is not yet fully mature and a significant amount of development is

still required to refine the details to the specific requirements of fuel tank wet-bay protection.

a) Some technologies are out-dated and need to be revisited in light of the current stateof-the-art.

b) Specific design philosophy is needed in each system to adequately address the

resulting tank pressures due to the discharge of the suppressant with various liquid

levels and ullage volumes (i.e., submerged discharges, excess suppressant release

{pressure} and insufficient suppressant release {concentration}).

c) Addition of redundancy, multiple discharges, is needed to meet the potential of

recurring ignition.

d) Minimization of in-tank wiring and introduction of potential ignition sources.
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e) Alternate suppressants necessary to reduce reliance on Halon 1301.

1) Alternate suppressants must be compatible with the temperature, altitude

and contamination requirements of fuel systems in general.

2) Alternate suppressants must be compatible with engine components and

subsystems.

f) Mature system designs are required to establish

1) Comparable installation cost and weight estimates.

2) Appropriate maintenance procedures and intervals.

g) Reliable operation.

1) Inspections for pressurized containers must be defined and evaluated.

2) Reliability to perform when commanded must be proven.

3) Reliability against uncommanded discharges must also be proven.

4) In depth evaluation of failure modes and hazard assessments.

h) Appropriate ground safety systems and procedures must be developed to protect

ground and maintenance personnel during open tank maintenance.
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5. References:

5.1. Documentation Received:

The following documents (in alphabetical order) have been received and reviewed:

5.1.1. AFWAL-TR-07-3032, (AFWAL/FIES, WPAFB, OH 45433-6553) Aircraft Dry Bay Test

Evaluation, by H.F. Robiadek, Boeing Military Airplane Company, Seattle, WA 98124-

2207 for Flight Dynamics Laboratory, Air Force Wright Aeronautics Laboratories, Air

force Systems Command, Wright-Patterson AFB 45433-6553, Excerpts.

5.1.2. Graviner Explosion Protection System Installation and Maintenance Manual, excerpts of.

5.1.3. Graviner Report Number 32-001-04, Suppression of Fuel Tank Explosions - An

Assessment of Efficacy for McAir, P.E. Moore, N.S. Allen, 18 November 1986.

5.1.4. IMECHE Conference Presentation, on Oct 27-30, 1987, Fire Protection and

Survivability, D.N. Ball, Graviner

5.1.5. JTCG/AS-87-T-004, Critical Review of Ullage Code, Dr. N. Albert Moussa, September

1989.

5.1.6. JTCG/AS-87-006, Compartmentalization Aircraft Wing Tank Active Ullage Explosion

suppression Tests, Final Report, J. Hardy Tyson, July, 1988.

5.1.7. JTCG/AS-89-T-006, Evaluation of the Linear Fire Extinguisher (LFE); Volume 1:

Explosion Suppression and Dry Bay Fire Suppression Ballistic Test Program. John F.

Barnes, Sept ‘89 Prepared for the Joint Logistics Commanders Joint Technical

Coordinating Group on Aircraft Survivability

5.1.8. JTCG/AS-90-T-003, Fire/Explosion Protection Characterization and Optimization: Phase

ii Alternative Dry Bay Fire Suppression Agent Screening Everett W. Heinonen, Ted A.

Moore, Jonathan S. Nimitz, Stephanie R. Skaggs, and Harold D. Beeson; New Mexico

Engineering Research Institute, The University of New Mexico, Albuquerque, NM.

October 1990.

5.1.9. JTCG/AS-91-VR-002, Evaluation of the Linear Fire Extinguisher (LFE) Volume ii,

Water-Based Explosion Suppression Agents Ballistic Test Program, John F. Barnes and

James R. Duzan, Sept 1991.

5.1.10. Kidde Graviner Report Number 32-009-01, Results of Active Ullage Explosion

Suppression Trials, NAWC - China Lake, 1-12 May 1995, A.J. Randle, 25 May, 1995.

5.1.11. Kidde Presentation material, Wichita, KS 16 April 1998.

5.1.12. NAWCWPNS TM 8006, Testing of Active Ullage Suppression Systems with Agents

Alternate to Halon 1301, Executive summary (Report not completed), A.B. Bernardo,

April 1997. Excerpts.

5.1.13. NIST SP 861: Evaluation of Alternative In-Flight Suppressants for Full-Scale Testing in

Aircraft Engine Nacelles and Dry Bays. William L. Grosshandler, Richard G. Gann and

William M. Pitts, Editors, April 1994.

5.1.14. NIST SP 890: Fire Suppression System Performance of Alternative Agents in Aircraft

Engine and Dry Bay Laboratory Simulations, Volumes 1 and 2, Richard G. Gann, Editor,

November 1995.

5.1.15. Pacific Scientific - Electro Kinetics Presentation material, Duarte, CA, 1 May 1998.

5.1.16. Primex Aerospace Presentation materials, Wichita, KS, 16 April 1998.
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5.1.17. SD90-007: Response to Request for Information, Lockheed Letter 5261 LMK/129/001 P7A Ullage Protection system, January, 1990.

5.1.18. SURVIAC-TR-89-021 Gas Explosion Suppression Agent Investigation, Final Report,

July 1989, Survivability/Vulnerability Information Analysis Center (SURVIAC) Booz -

Allen & Hamilton Inc, 4141 Colonel Glenn Highway, Suite 131, Beavercreek, Ohio

45431

5.1.19. Walter Kidde Aerospace, Proposal Number 7300-700: Ullage Protection System for P7A Aircraft

5.1.20. Whittaker Safety Systems Presentation materials, Simi Valley, CA, 1 May 1998.

5.1.21. WL-TR-91-3008, Fire/Explosion Protection Characterization and Optimization Phase I -

Data Analysis and Documentation Ullage Protection via Various Venting and Inertant

Combinations - Final Report, N. Albert Moussa, John J. Murphy, Jr., May 1991.

5.2. Interviews conducted:

5.2.1. The following companies, facilities and individuals (in alphabetical order) were

contacted:

5.2.1.1. Kidde Aerospace and Defense: Including Fenwal, Kidde Graviner, Santa

Barbara Dual Spectrum, L’Hotellier & Walter Kidde Aerospace:

Tom Hillman, 919-237-7004

5.2.1.2. National Institute of Standards and Technology (NIST):

Dr. Richard G. Gann, 301-975-6866

5.2.1.3. Naval Weapons Center, China Lake, CA:

Hardy Tyson, 760-939-3681

5.2.1.4. Pacific Scientific (Electro Kinetics Division):

Bill Meserve, 626-359-9317

Mike Fone, 805-963-2055

5.2.1.5. Primex (formerly Rocket Research of Olin Chemical Co.):

Paul Wierenga, 425-885-5000

5.2.1.6. Whittaker - Safety Systems Division (formerly Systron Donner):

Frank Bosworth, 805-584-4100

5.2.1.7. Wright-Patterson Air Force Base, Survivability Group:

Jim Tucker, 937-255-6052

Martin Lentz, 937-255-6302

5.2.2. The following companies (in alphabetical order) and individuals prepared and conducted

presentations on systems, equipment and/or technologies which range from fully

developed to a demonstrated promise for development into a usable product:

5.2.2.1. Kidde Aerospace and Defense, with representation from Fenwal: April 16, 1998

in Wichita, KS; Tom Hillman, John J. O’Neill, and Erdem A. Ural, PhD

(Fenwal)

5.2.2.2. Pacific Scientific: May 1, 1998 in Duarte, CA; Mike Fone and Bill Meserve

5.2.2.3. Primex Aerospace: April 16, 1998 in Wichita, KS; Paul Wierenga
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5.2.2.4. Whittaker Safety Systems: May 1, 1998 in Simi Valley, CA; Frank Bosworth

6. Background:

6.1. Active Explosion Suppression:

Systems have been developed to suppress explosions occurring in enclosed fuel tank spaces and

dry bay spaces. This is achieved by very quickly sensing the actual explosion and then very

rapidly discharging a suitable suppression agent (suppressant). These systems have successfully

demonstrated their ability to extinguish explosions, to prevent damage due to explosive overpressure, and to prevent sustained fires in extensively documented military research and testing.

Similar explosion protection systems have been used in various industrial applications, in military

aircraft in the fuel tank ullage and dry bay applications, and in commercial aircraft in vent box

applications.

Typical systems designed for the most recent use on military aircraft in dry-bay protection

systems, consist of optical detector systems, control unit/power supply systems, and suppressor

systems.

6.1.1. Detector System:

The detector system provides an output to the control unit/power supply system,

identifying that a hydrocarbon fire is present and, by the nature of the detector installation

design, where the fire is located. Due to the extremely rapid response time required,

optical detection is necessary.

6.1.2. Control Unit / Power Supply System:

The control unit / power supply system receives the electrical output from the detectors,

and any other necessary input (such as fuel level information in the case of fuel tank

ullage protection case), and commands the discharge of the suppressant system. Current

technology allows a wide range of design configurations, from numerous small, simple

systems, monitoring neighboring portions of the area to be protected, each capable of

discharging suppressant within their specific area of influence, to large integrated systems

which monitor the entire area to be protected, adjusting for changes in ullage volume, and

capable of controlling the discharge of suppressant throughout the entire area or partial

areas.

6.1.3. Suppressor System:

The suppressor system consists of the suppressant (suppression agent), the suppressant

storage container, the suppressant release mechanism (solenoid valves, squibs and rupture

disks, etc.) and the distribution network (ports or tubing if appropriate). The signal from

the control unit / power supply system is used to activate the suppressant release system.

Current technology offers a number of different types of suppressant dispersal systems.

Solid propellant gas generators produce inert gaseous exhaust (N2, CO2 and H2O) which

can be used directly to purge a volume of combustible vapors or air (principally O2), or

can be used to drive a quantity of suppressant from the associated canister and into the

volume being protected, low vapor pressure suppressants (such as Pentane, water or

water/AFFF mix) can be thrown from a scored container by the shock action of a small

explosive within the canister, or a high vapor pressure or pressurized suppressant (such as

Halons or pressurized water, AFFF mix) can be released by the explosive rupture of the

pressurized storage container or associated rupture disks. These technologies have been

demonstrated in numerous ground tests and shown to have significant merit.

6.2. Why the Military uses this technology:
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During the Viet Nam War, a significant percentage of the aircraft losses were directly attributed to

the US aircraft being highly vulnerable and minimally survivable when hit by small -to-medium

arms fire. As a result of this assessment, the Armed Services formed joint services task groups

dedicated to identifying combat aircraft vulnerability and improving their inherent survivability.

One such task group is the Joint Technical Coordinating Group on Aircraft Survivability

(JTCG/AS) based at Wright-Patterson AFB, Ohio. In roughly the same time frame, the UK began

development of fuel tank ullage protection systems.

6.3. Military Service Experience and History with this technology:

In the UK, Graviner, LTD designed and fielded a fuel tank ullage protection system which utilized

an Infrared (IR) optical sensor, a controller and a series of canisters filled with liquid Pentane,

strategically positioned within the fuel tank. Field experience has been accumulated on the AVRO

Vulcan, the Handley Page Victor, the Vicker Valiant and the Hawker Hunter, but the general data

available does not provide a complete service history. Some of these aircraft were still in

operation in the early 1990’s, and as far as this writer knows, the ullage protection systems also

remained operational.

This is the only ‘operational’ fuel tank ullage protection system uncovered in this technology

investigation and as such, provides limited confirmation of the technology’s overall success. In

practice, the Graviner system has been credited with a number of ‘saves’ (suppression of actual

fuel ignition), but has also been credited with a number of ‘false alarms’ (uncommanded

discharges).

7. Design Alternatives:

No alternative designs were investigated.
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8. Design and Installation Requirements:

This section identifies the considerations that need to be addressed in the design and installation of possible

systems developed around the explosion suppression technologies described within this report.

8.1. Optical Detector Systems:

8.1.1. Design:

The number and placement of detectors required to protect a fuel tank ullage space or a

dry bay is dependent upon the volume of the tank or space, the area affected, and the

internal physical geometry, including physical obstructions such as spars, ribs, bulkheads,

baffles, stringers, fluid lines and quantity indication probes, which obstruct the clear

visual fields of the detector.

Hydrocarbon fuel fires produce radiant energy in the spectral range of 0.10 to 100 micron

wavelengths, with most of the radiant energy emitted in the infrared region between 0.7

and 10 microns and a strong emission band at 4.4 microns due to the carbon dioxide

molecule excitation. It should be noted that commonly used aviation fuels, including

Avgas, exhibit almost identical spectral characteristics.

Optical detectors are of two general types, thermal and photon.

8.1.1.1. Thermal Detectors:

Thermal detectors produce an electrical output in response to absorbed, radiant

energy and the subsequent heating of a sensing element. These detectors have a

response time dependent on the amount of energy received per unit time by the

sensing element and the temperature change rate per unit of time of the sensing

element.

8.1.1.2. Photon Detectors:

Photon detectors produce an electrical output in response to absorbed photons.

Appropriate filtering lenses are utilized to ‘focus’ each photoelectric sensor on

the desired wavelength and color temperature, thereby tailoring the sensor to

respond to a specific input. Since heating of a sensing element is not required,

photon detectors have much sorter response times and can detect smaller energy

sources reliably over a greater range of distances.

Discriminating detectors have an ability to distinguish between anticipated

extraneous light sources such as electrical sparks, welding arcs, lightning,

maintenance lighting, sunlight, etc., and the actual ignition event. Current

technology sensors may contain multiple photoelectric sensors within a detector,

each filtered to a different, specific wavelength and utilization logic. These

detectors can greatly reduce or eliminate the potential for false alarms.

8.1.2. Installation:

The current technology in detectors allow a range of installations from completely within

the fuel tanks and ullage spaces, to remote mounting outside the fuel tank and ullage

space, using optical cables and appropriate penetrations or windows to monitor the

volume within.

A significant number of sensors are required due to the sensor’s limited field of view and

the internal tank obstructions. In a new aircraft design, such concerns can be optimized

to provide the best coverage with the fewest number of sensors.

8.2. Control Unit / Power Supply Systems:
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8.2.1. Design:

The number of control / power supply units are dependent on the ‘zone’ definition used

in the overall protection scheme being implemented. Each unit is designed to electrically

receive signals from a number of sensors and to electrically trigger the appropriate

number of suppression systems in response. Additionally, some technologies reviewed

can require the input of liquid levels within the tank to minimize the pressure rise effects

from the discharge of the suppressors. If the installation of such a system is to be made

in an aircraft which has an MMEL item for inoperative fuel quantity indication systems,

an independent means of determining the fuel level (or ullage volume) will be necessary.

If a single unit is expected to provide protection for an entire tank or tank system, then all

sensors report to the single control / power supply unit (a single ‘zone’ system).

Similarly, multiple ‘zones’ might be defined to protect an extended tank system.

Due to the importance of systems such as these, functional status from either power-up

BIT checks or continuous BIT checks must be reported to the cockpit, in the preferred

format for the particular aircraft type or design.

8.2.2. Installation:

The control / power supply is designed to be installed in a dry environment, and

electrically connected to the sensor systems and the suppressor systems. Inputs from the

aircraft fuel quantity indicating system or a dedicated liquid level indication system may

be required.

8.3. Suppressor Systems:

8.3.1. Design:

The number and placement of suppressors required to protect a fuel tank ullage space or a

dry bay is dependent upon the volume of the tank or space, the area affected, and the

internal physical geometry, including physical obstructions such as spars, ribs, bulkheads,

baffles, stringers, fluid lines and quantity indication probes, which impede the dispersal

of the suppressant.

The systems design must provide protection for the worst case situations, i.e., turbulent,

hot, high aromatic fuel. The basic requirements to be addressed in the design are:

a) Rapid dispersal time: Dispersal of the suppressant must occur in 10 to 25

msec.

b) Adequate Suppressant Concentration:

c) Ability to discharge the agent without creating unacceptable loads in the

mounting and adjacent structure.

d) Ability to adjust the amount of suppressant discharged to account for

varying ullage volume.

e) The initiating system and its attendant electrical power source and supply

system must not add an explosion hazard to the fuel tank environment.

f) Suitable safeguards and maintenance procedures must be in place to ensure

inadvertent suppressant discharge does not occur with personnel in the

tanks.

g) Suitable power-up or continuous BIT capability must be provided.
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8.3.1.1. Suppressant:

The suppressant used or chosena) Must fully transform at the lowest predicted in-service temperature

b) Must have satisfactory fire suppression characteristics.

c) Must be environmentally acceptable and governmentally approved.

d) Must not present a substance health hazard to maintenance personnel.

e) Must not have any adverse effects on the fuel usability following agent

discharge into a tank.

f) Must not have an adverse effect on the tank structure or other tank mounted

equipment through corrosion or other deterioration.

8.3.1.2. Suppression System Container:

The container types developed thus far have the following shapes: tubular,

cylindrical, hemispherical, and conventional fire bottle design. The means of

initiating the agent discharge is electrical operation of solenoid valves, fire

extinguishing agent squibs, and other pyrotechnic initiators.

The suppression system used must possess the following qualities:

a) At discharge, the tank over-pressure created must be acceptable.

b) At discharge, the thrust loads imposed on support structure must be

acceptable.

c) Must provide long life of the assembly including the contents and

the initiating system.

8.3.2. Installation:

A typical system requirement is for sufficient electrical system capacity to provide the

combined current draw for simultaneous initiation of multiple suppressors. While this

current draw is high, it is of brief duration. If an existing aircraft electrical system were

unable to meet this requirement, means are available to provide it.

Special structural provisions may be required to handle the high thrust loads created by

the tubular linear fire extinguisher system (LFE) manufactured by Whittaker. Lesser

addition thrust loads may also be exhibited by the Kidde hemispherical suppressors and

by the Primex gas generator system. No thrust loads are generated by the Kidde

cylindrical suppressor system.

9. Technical Data:

9.1. Kidde Aerospace and Defense

Kidde Aerospace and Defense now includes Fenwal Safety Systems, Kidde Graviner, Santa

Barbara Dual Spectrum, L'Hotellier, and Walter Kidde Aerospace.
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The research conducted on the original Graviner system dates prior to 1951. In 1954, a British

patent was granted to Graviner Manufacturing Ltd. (Now Kidde-Graviner)

Graviner suppression systems utilizing IR optical sensors and pentane suppressant were fitted to

the following British military aircraft: AVRO Vulcan, Handley Page Victor, Vickers Valiant, and

Hawker Hunter. It is reported that "saves" have occurred with these systems. False initiations

also were experienced.

A lot of IR sensor development has occurred since the original systems were installed. The status

of present day IR sensor technology as used in Kidde dry bay suppression systems being flown on

the F-18, F-22, EH-101, and V-22 aircraft allows for the successful recognition of and response to

hydrocarbon fires and the exclusion of response to specific anticipated false light sources. Present

sensors weigh 0.25 pounds and utilize 28 VDC power at 5 mA. The response time is 2 to 3

milliseconds and can be made quicker. Sensors would be located outside the tank, with optical

viewing ports through the tank walls or flange mounted on the inside tank wall with wires passing

directly through the wall. The number of sensors will vary with the size of the tank. The

controller / power supply unit would be provided to satisfy the various system requirements when

established, including BITE and flight deck annunciation. Sequential firing can be provided

should the simultaneous firing current exceed the instantaneous current capacity of the aircraft

electrical system.

9.1.1. Kidde Technical Data

9.1.1.1. Weight

The system weights were provided and are shown on Figure 9.1.

If the threat area within a tank can be considered localized, the system can be

tailored to the localized area and all impacts would be greatly reduced,

accordingly. Such a concept, if feasible, would be highly desirable.

9.1.1.2. Size (cargo/passengers/fuel displaced)

No size estimates were performed.

9.1.1.3. Range Impact

No range impacts were performed.

9.1.2. Certifiability status

While this technology has been used on military aircraft, it has not been used on

commercial aircraft in fuel tank ullage explosion suppression. Use on commercial

aircraft would require design, structural and electrical load analysis, and testing of

effectiveness of a specific system, a reliability analysis, operational impact determination,

and approval of a suitable suppressant.

9.1.2.1. Similarity to previous tests or flight experience

The Graviner system has received substantial laboratory testing and has been

used on the following British aircraft in fuel tank ullage protection: AVRO

Vulcan, Handley Page Victor, Vickers Valiant, and Hawker Hunter. Very

similar dry bay protection systems have been used in the following US aircraft:

F-18, F-22, EH-101, and V-22.

9.1.2.2. Additional Testing or Analysis
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A test program for a proposed commercial aircraft design would need to be

accomplished, as discussed in 9.1.2. Later technology sensors would need to be

verified to not cause inadvertent initiation. The final design should be tested at

various fuel quantities to verify prevention of over-pressure.

9.1.2.3. Other Effects on the Aircraft

No other effects have been identified.

9.1.3. Safety

Ullage explosion protection systems have been installed in British military aircraft used

in service. No safety problems are known.

9.1.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)

Substantial testing has proven that an explosion suppression system of this type

can prevent structurally damaging over-pressures, even for threats due to high

energy ignition sources resulting from tank penetrations by various types of

armaments.

9.1.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events

It is believed that explosions resulting from the lower energy ignition sources,

which might occur in commercial aircraft, could be successfully suppressed

based on the protection which is currently provided against the much higher

energy ignition sources caused by armament penetrations of dry bays on F-18,

F-22, EH-101, and V-22 aircraft.

9.1.3.3. Negative Impacts

9.1.3.3.1. Increased Landings due to range reduction (due to the added weight)

Increased landings would occur due to fuel volume reduction only if

portions of the suppression system are located below the surface of the

fuel. It is anticipated that all the sensors and most or all of the currently

available hemispherical type suppressors could be located in the ullage,

no fuel volume reduction would occur and no increases in landings

would be expected.

Aircraft range reduction due to the added weight of a hemispherical

type suppressor system has been calculated to be approximately as

follows:

Large Transport: 6.38 nautical miles

Medium Transport: 8.19 nautical miles

Small Transport: 11.88 nautical miles

747 Center Wing Tank only: 2.24 nautical miles

Therefore, the effect of range reduction on landings is considered

negligible.

9.1.3.3.2. Increased landings due to extra fuel consumed

Increased landings, due to increased fuel consumption caused by added

system weight, would occur. The magnitude of the increase could
24 June 1998

Task Group 2: Explosion Suppression

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vary, due to the complexity of the system configuration chosen. The

maximum suppression system weights are shown in the data table

included in 9.1.4, Cost Impact.

The additional block fuel consumed at constant range due to the added

weight of a hemispherical type suppressor system has been calculated

to be as follows:

Large Transport: 0.080 % increase

Medium Transport: 0.082 % increase

Small Transport: 0.092 % increase

747 Center Wing Tank only: 0.028 % increase

Therefore, the effect of additional fuel consumption on landings is

considered negligible.

If the option was chosen, of protecting only the ignition source threat

area in only one tank, the negative impact would be greatly reduced due

to a minimum system weight. The weight of this option has not been

defined.

9.1.3.3.3. Personnel Hazards

Inadvertent system operation has occurred with early type sensors.

This is not expected with the later technology sensors presently being

used. The observation of proper in-tank maintenance procedures is

necessary with any such systems and must include system disarming

prior to tank entry for maintenance.

9.1.3.3.4. Aircraft Hazards or Effects

To avoid any hazard related to tank over-pressure associated with the

discharge of the system, it is designed to sense fuel level and discharge

the amount of suppressant required by the ullage volume present.

To avoid or minimize the addition of wiring within the tank, the design

can provide for sensors mounted against the inside surface of outside

tank walls with wiring outside the tank. Tank level information can be

provided from level sensors mounted inside the tank, with wiring in

conduits where sensors are not mounted on tank outside walls.

For any suppressors which can not be mounted on outside tank walls,

wiring for suppressor initiation at a momentary 5 amps per suppressor,

must be housed in conduits inside the tank.

9.1.3.3.5. Other Equipment Hazards or Effects

Other equipment hazards have not been identified.

An equipment effect worthy of note is the possibility of the fuel

quantity system MEL item being deleted in support of the suppressor

system. The suppressant system, in most applications, requires some

type of fuel quantity or fuel level input. The fuel quantity system, if

used for this purpose, might be removed from the MEL, as one option..

9.1.4. Cost Impact
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9.1.4.1. Component Costs and Standard Aircraft Matrix Summary

The system cost and weight are shown in Table 9.1.

9.1.4.2. Retrofit

9.1.4.2.1 Design Costs

These costs have not been calculated due to lack of data.

9.1.4.2.2 Installation Costs

The installation labor cost per aircraft is estimated to be as follows if

accomplished during scheduled maintenance while fuel tanks are open

and are based on a labor rate of $45 / m-hr:

Large Transport: $16,650

Medium Transport: $11,925

Small Transport: $6,840

747 Center Wing Tank only: $9,540

9.1.4.2.3 Operational Costs

There are no known system operational costs.

9.1.4.2.3.1 Maintenance Costs

9.1.4.2.3.1.1 Scheduled Maintenance Costs

The scheduled maintenance man-hour requirements

are estimated to be as follows:

Note: Check interval varies with aircraft type and

operation.

Daily / Weekly: None.

C-checks (@ 18 to 24 mo.): 1 m-hr for BITE check.

D-checks (@ 6 to 8 years): 1 m-hr for BITE check.

9.1.4.2.3.1.2 Periodic Parts Replacement Costs

Detonator replacement is estimated to be required at

10 year intervals and would occur at heavy

maintenance; however, the material cost is not

available.

9.1.4.2.3.1.3 Unscheduled Maintenance Costs

These costs, comprised of costs of delays,

cancellations, out-of-service time, and maintenance

man-hours and materials, have not been determined

due to lack of reliability data.

9.1.4.3. Current Aircraft (Production Incorporation and Continued Production)

9.1.4.3.1 Design Costs
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These costs have not been calculated due to lack of data.

9.1.4.3.2 Installation Costs

These costs have not been calculated due to lack of data.

9.1.4.3.3 Operational Costs

There are no known system operational costs.

9.1.4.3.3.1 Maintenance Costs

9.1.4.3.3.1.1 Scheduled Maintenance Costs

The scheduled maintenance man-hour requirements

are estimated to be as follows:

Note: Check interval varies with aircraft type and

operation.

Daily / Weekly: None.

C-checks (@ 18 to 24 mo.): 1 m-hr for BITE check.

D-checks (@ 6 to 8 years): 1 m-hr for BITE check.

9.1.4.3.3.1.2 Periodic Parts Replacement Costs

Detonator replacement is estimated to be required at

10 year intervals and would occur at heavy

maintenance; however, the material cost is not

available.

9.1.4.3.3.1.3 Unscheduled Maintenance Costs

These costs, comprised of costs of delays,

cancellations, out-of-service time, and maintenance

man-hours and materials, have not been determined

due to lack of reliability data.

9.1.4.4. New Aircraft

9.1.4.4.1 Design Costs

These costs have not been calculated due to lack of data.

9.1.4.4.2 Installation Costs

These costs have not been calculated due to lack of data.

9.1.4.4.3 Operational Costs

There are no known system operational costs.

9.1.4.4.3.1 Maintenance Costs

9.1.4.4.3.1.1 Scheduled Maintenance Costs
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These costs have not been calculated due to lack of

data.

9.1.4.4.3.1.2 Periodic Parts Replacement Costs

Detonator replacement is estimated to be required at

10 year intervals and would occur at heavy

maintenance; however, the material cost is not

available.

9.1.4.4.3.1.3 Unscheduled Maintenance Costs

These costs, comprised of costs of delays,

cancellations, out-of-service time, and maintenance

man-hours and materials, have not been determined

due to lack of reliability data.
24 June 1998

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Table 9.1. Estimated Explosively Discharged Suppressant Systems Weight and Procurement Costs

 Kidde - Explosion Suppression System

Estimates are for Pentane-based Suppressant

Tank Vol.

(US Gal)

Sensors

qty/wt

(#/lb)

Suppressor

qty/wt (#/lb)

Controller

weight (lb)

Misc

weight

(lb)

Total

System

weight (lb)

Est Costs ($) *

Large Transport

+ Canister Suppressor 25000 50/20.0 400/280.0 4 20 324 $303,000

Hemi Suppressor 50/20.0 125/312.5 4 62.5 399 $150,500

Medium Transport

+ Canister Suppressor 10000 35/14.0 250/175.0 4 15 208 $196,500

Hemi Suppressor 35/14.0 85/212.5 4 42.5 273 $106,000

Small Transport

+ Canister Suppressor 2000 20/8.0 100/70.0 4 10 92 $90,000

Hemi Suppressor 20/8.0 40/100.0 4 20 132 $58,000

747 CWT

+ Canister Suppressor 17000 40/16.0 378/264.6 4 18 302.6 $278,800

Hemi Suppressor 40/16.0 40/100.0 4 20 140 $76,000

+ Canister is an out-of-production design

* Ball-park costs based on units identified in study and current production costs.

 No estimates made for installation on new acft or as a retrofit on existing acft.
24 June 1998

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9.2. Pacific Scientific / HTL

Pacific Scientific is a major supplier of cargo compartment fire extinguishing systems and

components, pneumatic products for missiles, automatic fire suppressions systems for military

ground vehicles. The technology applicable to explosion suppression are optical sensors, Halondischarge bottles, and a near “drop in” Halon replacement agent called Triodide.

9.2.1. Pacific Scientific / HTL Technical Data

The military ground vehicle explosion suppressions systems must suppress a

fire/explosion in occupied vehicles such as tanks and armored personnel carriers. The

over-pressures, heat, oxygen concentration, hydrocarbon combustion by-products, and

the toxicity of the agent must be survivable and meet military specifications. The sensor

is a discriminating, three-frequency optical sensor which has good false alarm immunity

and will not fire the suppressant for a long list of false light sources. The Halon bottles

are solenoid activated, not squib activated. The F-22 dry bay protection system has

multiple bottles with sensors on each bottle, and BITE check capability.

Pacific Scientific / HTL does not manufacture and have not tested explosion suppression

systems for fuel tanks, only for applications in dry bay and occupied areas. Significant

development would be required to adapt their current technologies to fuel tank

applications. It is not known how much signal attenuation and signature shift would

occur with a fuel film over the sensors and how their discharge bottles would react in a

submerged environment. Further development would be required to account for variable

ullage and discharge pressure by using microprocessor controls and multiple bottle

arrays.

9.2.1.1. Weight

No weight estimates were developed since the applicability of this technology is

not known for explosion suppression in fuel tanks. No detailed design was

performed and no weight data was submitted

9.2.1.2. Size (cargo/passengers/fuel displaced)

No sizing estimates were developed.

9.2.1.3. Range Impact

No range impact estimates were developed.

9.2.2. Certifiability status

Pacific Scientific explosion suppression systems have not flown on commercial airplane

and have not been previously certified. This technology has been qualified in military

applications, but not on commercial aircraft. Consequently, an extensive and rigorous

analyses and testing programs would be required to prove the effectiveness of the

technology and design, the safety of the aircraft, and the system reliability.

9.2.2.1. Similarity to previous tests or flight experience

No previous ground or flight testing have been done for this technology on

commercial aircraft.

9.2.2.2. Additional Testing or Analysis
24 June 1998

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A complete testing program will have to be performed to demonstrate proof of

concept and design, before any certification testing can be performed.

Prevention of tank over-pressures in a variable ullage volume and the effects of

discharging the agent under the fuel would have to be demonstrated.

9.2.2.3. Other Effects on the Aircraft

No other effects on the aircraft have been identified.

9.2.3. Safety

The effectiveness of this technology for explosion suppression in fuel tanks has not been

demonstrated or determined. If this could be demonstrated, then the safety of discharging

into a variable ullage volume and possible discharges under the fuel would have to be

demonstrated. Possible wing over-pressurization could result if the system designed for

an empty tank discharges into a full tank. Also, the hydraulic ram effect of discharging

the agent under the fuel could cause the tank to rupture.

9.2.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)

The effectiveness of this technology has not been demonstrated in preventing

over-pressures in fuel tanks, only in military aircraft dry-bays.

9.2.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events

No evaluation was performed since the capabilities of the technology has not

been demonstrated for explosion suppression in fuel tanks.

9.2.3.3. Negative Impacts

9.2.3.3.1. Increased Landings due to range reduction (due to the added weight)

No evaluation was made.

9.2.3.3.2. Increased landings due to extra fuel consumed

No evaluation was made.

9.2.3.3.3. Personnel Hazards

Since the inadvertent firing of the agent when personnel are in the tank

is a potential threat, the system would be de-energized before entering

the tank.

9.2.3.3.4. Aircraft Hazards or Effects

Possible tank over-pressures could result from the discharge of agent

sized for an empty tank when the tank is full. Also the hydraulic ram

effect if the agent is discharged under the fuel could rupture the tank.

System designs would need to avoid these conditions.

9.2.3.3.5. Other Equipment Hazards or Effects

None has been identified.

9.2.4. Cost Impact
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Since the technology has not been demonstrated to protect against explosions in fuel

tanks and an system design was not developed, an exhausting cost benefit was not

performed. Only the ROM costs below was provided by Pacific Scientific / HTL:

DESCRIPTION QTY $ EACH $ TOTAL

Optical Sensor 8 900.00 7,200.00

Amplifier 1 5,000.00 5,000.00

Extinguisher 8 1,600.00 12,800.00

Control Unit 1 5,000.00 5,000.00

Cable Harness 1 set 15,000.00 15,000.00

Brackets/Misc. fixing devices 1 set 10,000.00 10,000.00

TOTAL $45K.

9.2.4.1. Component Costs and Standard Aircraft Matrix Summary

No data available.

9.2.4.2. Retrofit

No data available.

9.2.4.3. Current Aircraft (Production Incorporation and Continued Production)

No data available.

9.2.4.4. New Aircraft

No data available.

9.3. Primex Aerospace Company (Including the former Olin Aerospace Company)

9.3.1. Primex Technical Data

Primex produces various fire suppression and explosion protection technologies which

are installed on various military aircraft. The technology applicable to explosion

protection are chemical gas generator systems, similar to the gas-air-bag technology in

automobiles. This generates a large volume of gas in milliseconds from an electrically

initiated, exothermic reaction releasing carbon dioxide, nitrogen, water and trace

compounds. The gas generation technology has been successfully demonstrated in live

fire testing to protect a fuel tank from catastrophic over-pressure for armor piercing

incendiary threats (API), but was to slow to protect a fuel tank against a 23mm high

energy incendiary (HEI). However, the initiation of the gas generators was triggered by

the test apparatus or personnel and was not initiated by a reactive sensing devise which

would be required for explosion suppression systems on aircraft. There is sensing

technology available which could trigger the gas generation technology fast enough to

suppress an explosion, but this has not been demonstrated. Sensor initiated gas

generation systems have demonstrated compliance for aircraft dry bay fire/explosion

protection on the V-22 and F-18E/F aircraft.

The advantages to gas generation technology are as follows:
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a) Quickly disperses non-corrosive inerting agents without pressurized

containers

b) Long shelf life (20 years)

c) Low maintenance

d) No freezing point depression issues

e) Canisters are not powered except to trigger

f) Canisters can be installed in tank where required

g) Can be selectively discharged by a remote controller

h) Gas is radially discharged resulting in good suppressant dispersion and

creates no reaction loads on the aircraft structure

The disadvantages of gas generation technology are as follows

a) High temperatures of discharge gases

b) Controller must know ullage volume and fuel level (FQIS) to ensure tank is

not over-pressurized from variable ullage volumes and to ensure canister is

not activated under the fuel level (hydraulic ram effect may rupture tank)

c) Canister wiring must be routed in tank

d) Have not tested volumes larger than 120 cubic feet

e) Single shot canisters

1) Require tank entry after discharge

2) Containers are not re-usable

Another configuration that Primex has developed is a hybrid system where a liquid

suppressant is discharged by the gas generator. The expanding gases from the gas

generator expel a liquid suppression agent. This has been successfully tested in live fire

testing but the has not been demonstrated for fuel tank explosions. The advantages are as

follows:

a) Long shelf life

b) Low maintenance

c) Usable with any low pressure suppressant

d) No high pressure discharge into ullage

e) Low propellant weigh requirement

f) Ullage volume (FQIS) input to controller desired but not required

g) Canisters are not powered except to trigger
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h) Can be BITE checked

i) Controllers can selectively discharge canisters

j) Faster discharge rates than nitrogen charged systems

The disadvantages of the gas generator-hybrid system are:

a) Suitable low pressure suppressant needed

b) Water has been demonstrated effective but has freezing point issues

c) Canister triggering wiring and squibs-initiators must be located in tank

d) Single shot canisters

e) Requires tank entry to replace after discharge

9.3.1.1. Weight

The weight estimates shown in Table 1 are for the total tank volume, mains and

CWT. The bizjet tank volume is shown as 2000 gallons, but the standard

volume is 1200 gallons. The weights are quite low for all models compared to

other methods such as foam and nitrogen inerting. Any airplane structural

changes are not shown but would be minor.

9.3.1.2. Size (cargo/passengers/fuel displaced)

The canisters are 1-2” in diameter and up to 1’ long and would occupy a

minimal tank volume. The controller located outside of the tank would occupy a

small volume and would require no modifications to the airplane to install.

9.3.1.3. Range Impact

The only range impact would be carrying the additional weight shown in Table

9.3.

9.3.2. Certifiability status

9.3.2.1. Similarity to previous tests or flight experience

The Fenwal system on the Boeing 707 and 747-100 airplanes had an old

technology Halon fire extinguishing system, installed in the surge tanks to

prevent ground fires entering the wing. This system was only for fire protection

and not intended to be fast enough for explosion suppression. Although this

system was qualified and certified, there is little similarity to an explosion

suppression system in the tanks, other than the similar technology used. Putting

additional wiring and squib initiators in the fuel tanks presents a new set of

safety concerns which need to be addressed. A complete new certification

program would be required from proof of concept and design, considering

failure modes and effects analysis, full scale testing and flight testing would be

required for certification.

9.3.2.2. Additional Testing or Analysis

A complete new certification program is required from proof of concept and

design, failure modes and effects analysis, full scale testing and flight testing

would be required for certification.
24 June 1998

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9.3.2.3. Other Effects on the Aircraft

The FQIS would need to be functional for the controller to determine ullage

volume, this could not be MEL dispatchable as it is today. Accessing the data

bus would be required.

An alternative is to provide a dedicated fuel quantity measuring system to

provide an input to the suppression system, thereby eliminating the effect on the

aircraft FQIS and any MMEL alleviation provided.

9.3.3. Safety

9.3.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)

The gas generator technology has demonstrated effective in suppressing fuel

tank explosions for military threats up to API rounds. This is in excess to any

threats internal to the tanks. However, the gas generation technology was not

tested with a reactive sensor and has not been demonstrated system effectiveness

as would be installed on the airplane. There are extremely fast sensors which

have demonstrated effectiveness with other explosion suppression technology in

fuel tanks. Therefore it is likely that the gas generation technology could be

effective in suppressing fuel tank explosions. The gas generation-hybrid

technology has shown effective in dry bay applications but not in fuel tank

applications.

9.3.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events

This technology was not evaluated against the historical events because the total

system (sensors and gas generators) has not demonstrated effectiveness for fuel

tank explosion protection.

9.3.3.3. Negative Impacts

9.3.3.3.1. Increased Landings due to range reduction (due to the added weight)

No evaluation was made.

9.3.3.3.2. Increased landings due to extra fuel consumed

No evaluation was made.

9.3.3.3.3. Personnel Hazards

Certainly if the system was activated with personnel in the tanks this

could result in serious injury. The system would have to be deactivated prior to any entry into the fuel tank.

9.3.3.3.4. Aircraft Hazards or Effects

Putting pyrotechnic devices (squib or pyrotechnic initiators) into the

tank may present a risk to the aircraft. A full safety analysis would be

required to determine the resulting level of safety for the system.

Presumably the fact that explosion suppressant would be released if the

squib was activated would ensure any ensuing explosion would be

suppressed.
24 June 1998

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9.3.3.3.5. Other Equipment Hazards or Effects

None have been identified.

9.3.4. Cost Impact

Only cost of procurement, shown in Table 9.3., have been evaluated. Since the complete

system (sensor and gas generators) have not been demonstrated effective in suppressing

fuel tank explosion, a complete costs analysis was not performed.

9.3.4.1. Component Costs and Standard Aircraft Matrix Summary

Refer to Table 9.3.

9.3.4.2. Retrofit

No data available.

9.3.4.3. Current Aircraft (Production Incorporation and Continued Production)

No data available.

9.3.4.4. New Aircraft

No data available.
24 June 1998

Task Group 2: Explosion Suppression Page 30

Table 9.3. Estimated Gas Generation and Hybrid Systems Weight and Procurement Costs

Primex - Solid Propellant Gas Generator Systems

Insert Gas produced by solid propellant

Tank Vol

(US Gal)

Sensors

qty/wt (#/lb)

Suppressors

qty/wt (#/lb)

Controller

weight (#)

Misc Weight

(lb)

Tot System Wt

(lb)

Est. Tot System Cost

($)*

Large Transport

Active 54,000 30 / 15.0 58 / 290 12.0 40.0 360 $163,500

Hybrid 30 / 15.0 29 / 145 8.0 30.0 200 $141,750

Medium Transport

Active 24,000 15 / 7.5 26 / 130 8.0 15.0 160 $92,000

Hybrid 15 / 7.5 13 / 65 5.5 10.0 90 $82,250

Business Jet

Active 2,000 4 / 2.0 4 / 10 3.0 1.0 20 $29,000

Hybrid 4 / 2.0 4 / 10 3.0 1.0 15 $29,000

* Cost estimates based on units identified in study and current production costs.

 No estimates made for installation on new aircraft or as a retrofit on existing aircraft.

Based on:

Suppressor unit weight = 5.0 lbs each (1000 gram agent)

Sensor weight = 0.5 lb each

Wiring weight = 0.012 lb/ft

Large Transport = 35 ft per component

Medium Transport = 25 ft per component

Business Jet = 10 ft per component
24 June 1998

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9.4. Whittaker Safety Systems

Whittaker Safety Systems (previously known as the John E. Lindberg Company and as Systron

Donner) is a major supplier of fire, smoke and bleed air leak detection and suppression and

detection control systems equipment for military and commercial aviation aircraft.

Whittaker designed the Linear Fire Extinguisher (LFE®) explosion suppression system in response

to a military RFP in 1985 for dry-bay protection against API and HEI threat. Original

requirements were for aluminum oxide powder as the suppressant, but testing showed this to be a

poor requirement and Whittaker Safety Systems moved to develop a Halon system using a similar

tubular container design.

9.4.1. Whittaker Technical Data

9.4.1.1. Weight

A comparison of weights, provided by Whittaker, of the Tubular Storage

systems to other protection systems (rigid foam, N2 Inerting, Halon Inerting,

Scott Foam, etc.) show the Tubular Storage system to be the lightest system per

unit volume protected. Specific weights are dependent on the detailed

requirements and the configuration of the installation being evaluated.

9.4.1.2. Size (cargo/passengers/fuel displaced)

Since the concept of the LFE® allows any physical length of tubing to be used, it

is not limited in length sizing. However, it is necessary that the container be

sized in diameter according to the amount of suppressant needed to protect the

volume of the tank being considered; the greater the container diameter, the

greater the resulting volume of suppressant to be released.

Due to the pressurized nature of the container, the volume of fuel displaced by

the suppressant storage system is minimized.

9.4.1.3. Range Impact

The only range impact would be carrying the additional weight of the system.

9.4.2. Certifiability status

9.4.2.1. Similarity to previous tests or flight experience

Whittaker Explosion Suppression System components were designed into the

wing structure and first tested on the Bell V-22 Tiltrotor aircraft. Later, similar

Whittaker components were tested on equivalent structures of the F/A-18 Naval

fighter. These tests were done in controlled testing environments where flight

conditions were simulated, but to this date, no system of this sort has flight

experience.

9.4.2.2. Additional Testing or Analysis

Further testing is required to determine the compatibility of the suppressant with

the environment and the fuels requiring protecting, especially considering

alternative suppressants. Testing must address the concerns associated with

potential over-pressures, the effects of discharging the LFE® when completely

submerged in fuel and the ability of successfully dispersing the agent into the

fueled areas.
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Further design and development work is necessary to understand and to

minimize the reactive loads that are imposed on the aircraft structure when the

LFE® is discharged. The testing to date have not shown these loads to be a

structural problem, but the nature of high magnitude, impulse loads require a

dedicated look at the effects, or potential effects.

A certification program is required to address the complete installation and

operation of the finalized system.

9.4.2.3. Other Effects on the Aircraft

The FQIS would need to be functional for the controller to determine ullage

volume, this could not be MEL dispatchable as it is today. Accessing the data

buss would be required.

An alternative is to provide a dedicated fuel quantity measuring system to

provide an input to the suppression system, thereby eliminating the effect on the

aircraft FQIS and any MMEL alleviation provided.

9.4.3. Safety

9.4.3.1. Effectiveness in preventing over-pressure hazard (from the explosion)

As described in 9.4.2.2. above, testing to address the concerns of over-pressures

must be conducted.

9.4.3.2. Evaluation against Historical Commercial Aircraft Over-pressure events

No evaluation was made.

9.4.3.3. Negative Impacts

9.4.3.3.1. Increased Landings due to range reduction (due to the added weight)

No evaluation was made.

9.4.3.3.2. Increased landings due to extra fuel consumed

No evaluation was made.

9.4.3.3.3. Personnel Hazards

Activation of this system with maintenance personnel in the tank

presents a hazard of serious injury. Positive and appropriate

deactivation procedures must be incorporated prior to entry into a tank

equipped with this suppression system.

9.4.3.3.4. Aircraft Hazards or Effects

Pyrotechnic devices in aircraft fuel tanks presents a risk to the aircraft.

A full safety analysis would be required to evaluate the resulting level

of safety of the aircraft. In the case of this suppression system, a

discharge of the system would release an explosion / fire suppressant

into the fuel tank and reduce any threat due to fire or explosion.

9.4.3.3.5. Other Equipment Hazards or Effects

None have been identified.
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9.4.4. Cost Impact

9.4.4.1. Component Costs and Standard Aircraft Matrix Summary

Only ROM cost of procurement, shown in Table 9.4., have been evaluated.

DESCRIPTION $ EACH

Optical Sensors $1,500

LFE® Units $800

Controller TBD

Brackets TBD

9.4.4.2. Retrofit

No installation data available.

9.4.4.3. Current Aircraft (Production Incorporation and Continued Production)

No installation data available.

9.4.4.4. New Aircraft

No installation data available.
24 June 1998

Task Group 2: Explosion Suppression Page 34

Table 9.4. Estimated Linear Fire Extinguisher System Component Costs

Whittaker Safety Systems - LFE® Suppressant System

FUEL TANK PROTECTION SYSTEMS

Rough Order of Magnitude

SYSTEM COST MATRIX SUMMARY

AIRCRAFT TYPES

(MTOGW - MLW)

PROJECTED

NUMBER OF TANKS

FUEL

VOLUME

(US GAL)

PROJECTED

NUMBER OF

DETECTORS

DETECTOR

COSTS

PROJECTED

NUMBER OF

EXTINGUISHERS

EXTINGUISHER

COSTS

TOTAL

COSTS

LARGE (800K - 600K) 5 54,000 10 $15,000 30 $24,000 $39,000

MEDIUM (330K - 270K) 5 24,000 10 $15,000 20 $16,000 $31,000

SMALL (160K - 130K) 3 4,000 6 $9,000 12 $9,600 $18,600

REGIONAL T/FAN (76K-69K) 3 3,200 6 $9,000 6 $4,800 $13,800

REGIONAL T/PROP (40K-38K) 2 1,400 4 $6,000 4 $3,200 $9,200

LARGE BIZJET (35K-30K) 3 2,000 4 $9,000 6 $4,800 $13,800
24 June 1998

Task Group 2: Explosion Suppression

Page 35

10. Other Supporting Data

10.1 Standard Aircraft Matrix

Proposed Standards for evaluation

airplane types

Units:

Weight pounds Volume US gallons

Speed knots Pressure psi

Altitude feet

Model Large Medium Small Regional Regional Bizjet

T/fan T/prop

General

 Fleet size 2,000 1,400 8,600 1,000 2,000 8,600

 MTOGW 800,000 330,000 160,000 78,000 40,000 23,000

 MLW 600,000 270,000 130,000 69,000 38,000 20,000

Fuel Volume:

 Total 54,000 24,000 5,000 3200 1400 1200

 Center 25,000 10,000 3,000 800 0 0

 Wing 26,000 12,000 2,000 2400 1400 800

 Tail 3,000 2,000 0 0

 Body (optional) (optional) (optional) 0 0 400

Tank Configurations

 % fleet with Center Tanks 89 97 6

 % of Center Tanks with Heat Input 0

 % fleet with Tail Tanks 36 25 0

 % fleet with Body Tanks 2 0 54

Tank Pressure

 Positive +1.5 +1.5 +1.5 2 2 +1.5

 Negative -0.5 -0.5 -0.5 -1 -1 -0.5

Bleed flow available after ECS

Bleed pressure avail after ECS

Bleed temperature avail after ECS

Precooler flow avail after ECS

Precooler max outlet temperature at max

flow

Payload (lbs) 100,000 55,000 40,000 35,000 22,000 1,200

passengers 400 250 150 75 50 6

Short mission

 Range (nm) 2,000 1,000 500 1000

 Ground Time (hr) 2.00 1.50 1.25

 Block Time (hr) 4.6 2.3 1.6

 # of flights per day (AOG data) 1,103 1,599 14,682

 # of airplanes in AOG data 757 608 3,552

 # of flights per day 2,914 3,682 35,548

Medium Mission

 Range (nm) 4,000 2,000 1,000 450 250 3000

 Ground Time (hr) 2.00 1.50 1.25 0.33 0.33

 Block Time (hr) 8.6 4.6 2.8 1.4 1.1

 # of flights per day (AOG data) 432 399 4,152

 # of flights per day 1,141 919 10,053 10,000 20,000

Long mission

 Range (nm) 6,000 4,000 2,000 6500

 Ground Time (hr) 2.00 1.50 1.25

 Block Time (hr) 12.7 8.9 5.1

 # of flights per day (AOG data) 206 235 1,060

 # of flights per day 544 541 2,566

Distribution

 % short missions 63 72 74 54

 % medium missions 25 18 21 100 100 27

 % long missions 12 11 5 19

Operating environment

 Max. Cruise Alt. 43,000 43,000 37,000 35,000 25,000 41,000

 Ground temp max 130 Deg F 130 Deg F 130 Deg F 122 Deg F 122 Deg F 122 Deg F

 Ground temp min -65 Deg F -65 Deg F -65 Deg F -40 Deg F -40 Deg F -40 Deg F

 Distribution of Ground Temp -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F

 Distribution of Cruise Temp -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F

 Distribution of Flash Point 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F

 Vmo 365 360 340 320 250 360

 Mmo 0.92 0.85 0.82 .0.80 0.5 0.83

 M cruise 0.85 0.80 0.77 0.75 290T/220E 0.8

 Climb rate (Max, Sea Level) 5,000 5,000 4,500 3000 2000

 Descent rate (Normal) 2,000 1,500 2,000 2000 2000

 Descent rate (Max) 3,500 4,000 3,000
TG3 1

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Fuel Tank Inerting

Task Group 3

Aviation Rulemaking Advisory

Committee
28 June, 1998

TG3 2

Abstract

This report is the findings of the Inerting Task Group, which was formed as a portion of

the Fuel Tank Harmonization Working Group activity established in January 1998. The

FAA initiated this activity by the issuance of a Harmonization Terms of Reference

entitled “Prevention of Fuel Tank Explosions” on 16 Dec 1997. The Working Group’s

stated task was to study means to reduce or eliminate fuel tank flammability and to

propose regulatory changes to the FAA Aircraft Rulemaking Advisory Committee.

The Inerting Task Group’s assignment was to provide a feasibility analysis of fuel tank

inerting systems. The analysis was to focus on reducing or eliminating exposure to

explosive mixtures for transport airplane operations. A cost/benefit analysis for inerting

systems was to be included for the fleet of aircraft requiring retrofit, for current

production aircraft, and for new type design aircraft.
28 June, 1998

TG3 3

Summary

The Inerting Task Group studied the technologies offered by the respondents to the

FAA’s Request for Information. Several technologies for providing inert gas were

reviewed including carbon dioxide in gaseous form and as dry ice, nitrogen in gaseous

and liquid form, and exhaust gas.

The group analyzed the impacts of carrying an on-board inerting system versus a groundbased system. In addition, the group studied the cost and benefit of inerting the center

wing tank only versus inerting all of the aircraft’s fuel tanks. Finally, two methods of

purging oxygen from the tank were reviewed i.e. “scrubbing” the fuel and “washing” the

ullage space above the fuel.

A ground-based system provides the potential for the least costly (non-recurring cost)

system on the aircraft. However, it requires a substantial investment in ground

equipment to supply inerting gas, plus the recurring costs of the inerting gas and

operation of the equipment.

Scrubbing fuel at the airport fuel farm, or on the aircraft during refueling, is the least

effective form of tank inerting. The ullage remains flammable during taxi, takeoff, and

initial climb until inert gas evolves from the fuel. As fuel is consumed from a fuel tank,

ambient air flows in to replace it and raises the oxygen concentration. The tank may only

be inerted for the latter portion of climb and the beginning of cruise and is highly

dependent of the initial fuel load. Clearly, this method provides little added protection to

today’s design. In addition, this method would provide no added protection for empty

fuel tanks, as was the case for the TWA800 center wing tank.

Ground-based ullage washing is effective when considered in combination with the

normal changes to fuel temperature during a flight. On average, the exposure to a

flammable, non-inert ullage is approximately 1%.

On-board systems could provide inert gas throughout the flight and offer zero exposure to

a flammable, non-inert ullage. There are several existing methods for providing nitrogen

on board an aircraft. It can be stored as a gas in bottles or as a liquid in Dewar bottles,

such as on the C-5. Either of these would require replenishment at an airport, which adds

to the cost of the airport infrastructure.

An alternative to storing gases or liquids, on-board inert gas generating systems

(OBIGGS) separate nitrogen from engine bleed air. Such systems exist on military

aircraft today, notably the C-17 as well as some fighters and helicopters. All of these

systems extract a performance penalty from the aircraft. A new aircraft design offers the

best opportunity to minimize these penalties. Current production aircraft and the retrofit

fleet may incur redesign and operational penalties that make them uneconomical to fly.

Operational compromises will almost certainly be required. Many of today’s aircraft do

not have enough bleed air available to supply these systems.
28 June, 1998

TG3 4

Whatever the type of inerting that might be used, there are potential hazards to personnel.

Gaseous inerting agents present a suffocation hazard and liquid nitrogen presents the

additional hazards of freezing trauma to skin and eyes.

Several other on-board systems were reviewed. Exhaust gas from the jet’s engines and

auxiliary power unit (APU) was deemed infeasible primarily because the exhaust

contains too much oxygen. Carbon dioxide in gaseous and solid (dry ice) form was also

deemed infeasible because it’s a greenhouse gas that adversely affects the environment.

Also, except for nitrogen systems, none of the systems were mature enough to be

considered for installation on commercial aircraft. Nitrogen is the best candidate at this

time.

The following table provides a summary of the cost and benefit of each system.

Technology Effectiveness Cost over 10 Years (US Dollars)

On-board Liquid Nitrogen for All

Tanks

100% $35.7B

On-board Gaseous Nitrogen for All

Tanks

100% $33.9B

Air Separator Modules for All

Tanks

100% $37.3B

Air Separator Modules for the

Center Tank

100% $32.6B

Ground-based Ullage Washing with

natural Fuel Cooling for Center

Tank

99% $4B with gaseous nitrogen

$3B with liquid nitrogen
28 June, 1998

TG3 5

Table of Contents Page No.

Abstract 2

Summary 3

Table of Contents 5

1. Introduction 7

2. References 8

2.1. Documents 8

2.2. Interviews 8

2.3. Presentations 8

3. Background 10

3.1. How technology works 10

3.2. Why Military uses this technology 11

3.3. Military Service Experience and History with this technology 11

4. Design Alternatives 12

4.1. Self-contained (aircraft-based) System 12

4.2. Ground-based System 12

4.3. Hybrid Systems 13

4.4. Body Tank or All Tanks 13

4.5. Fuel Scrubbing 13

4.6. Ullage Washing 18

4.7. Inert Gas Supply 25

4.7.1. Nitrogen 25

4.7.2. Carbon Dioxide 25

4.7.3. Exhaust Gas 26

4.7.4. Fuel Enrichment of the Ullage 27

5. Installation Requirements 28

5.1. Installation of Ground-Based Inert Gas Supply 28

5.1.1. Ground-based Scrubbing 30

5.1.2. Ullage Washing 30

5.2. Installation of Aircraft-based Fuel Tank Inerting 30

5.2.1. Overview 30

5.2.2. Air Separation 31

5.2.3. Exhaust Gas 31

5.2.4. Combustion (Carbon Dioxide) Systems 32

5.2.5. Cryogenic Systems 32

5.3. Installation Requirements for All Inerting Systems 32

5.3.1. Ground-Based Systems 32

5.3.2. Aircraft-Based Systems 32

6. Technical Data 35

6.1. Weight 35

6.2. Size (cargo/passengers/fuel displaced) 36

6.3. Cost 37

7. FAA Certification Requirements 38

7.1. Similarity/Previous Test or Flight Experience 38

7.2. Additional Analysis and Testing 38
28 June, 1998

TG3 6

7.3. Other Effects on Aircraft 38

8. Safety 39

8.1. Effectiveness in Preventing Overpressure Hazard 39

8.2. Evaluation against Historical Commercial Aircraft Overpressure Events 39

8.3. Negative Impacts 41

8.4. Increased Landings due to Range Reduction (due to added weight) 41

8.5. Increased Landings due to Extra Fuel Consumed 41

8.6. Personnel Hazards 41

8.7. Aircraft Hazards or Effects 41

8.8. Other Equipment Hazards or Effects 42

9. Cost Impact 43

9.1. Retrofit 43

9.1.1. Air Separator Technology 43

9.1.2. Liquid Nitrogen Technology 43

9.1.3. Simple Hybrid System 43

9.2. Current Aircraft 43

9.2.1. Air Separator Technology 43

9.2.2. Liquid Nitrogen Technology 43

9.2.3. Simple Hybrid System 45

9.3. New Aircraft 47

9.3.1. Air Separator Technology 47

9.3.2. Air Separation Technology – Center Tank Only 48

10. Conclusions 50
28 June, 1998

TG3 7

1. Introduction

Task Group 3, the Fuel Tank Inerting Group, of the Fuel Tank Harmonization Working

Group was tasked to assess current and future technologies which could drastically

reduce or eliminate flammable mixtures in fuel tanks of Part 25 aircraft. Inerting systems

provide an inert gas to displace the oxygen in the fuel and/or ullage resulting in a mixture

that cannot sustain combustion.

In early 1997, the FAA issued a Request for Comment asking the industry and the public

to propose and evaluate methods to reduce fuel tank flammability. Those respondents

who recommended inerting suggested the use of nitrogen, carbon dioxide, or exhaust

gases from engines or fuel burners as the inerting agent. Task Group 3 contacted all of

these respondents to learn more about their proposals and worked with several of them to

determine the viability of their proposals for existing and future aircraft.

Many of the respondents had hardware available or in the prototype stage and so were

best able to provide estimated cost, weight, and size of their proposed hardware for our

evaluation. Some of the respondents provided their conceptual ideas or patent

information. Given more time, the Task Group would have attempted to better define the

concepts and make an estimate of the cost, weight, and size of the system for inclusion in

the report. While this wasn’t possible, due to the short time available for the task, the

Task Group felt it important to include the conceptual ideas for future reference. The

Task Group also commented on the potential benefits and problems of the proposed

technology when fitted to a present day aircraft.

The Task Group also evaluated methods of displacing the oxygen in the fuel and/or

ullage with inert gas. We evaluated on-board systems to provide inerting gas on the

aircraft at all times during a flight as well as ground-based systems that provide inert gas

to the aircraft prior to flight. Fuel “scrubbing” and ullage “washing” were studied for

effectiveness and efficient use of the inert gas.
28 June, 1998

TG3 8

2. References

2.1. Documents

[1] “Test and Evaluation of Halon 1301 and Nitrogen Inerting against 23MM HEI”,

Charles Anderson, AFFDL-78-66, May 1978

[2] “A Study of the Blast and Combustion Over-Pressure Characteristics of the 23MM

High Explosive Incendiary-Tracer (HEI-T)”, Charles M. Pedriani and Thomas Hogan,

USAAVRADCOM-TR-80-D-33, November 1980

[3] “Inerting Conditions for Aircraft Fuel Tanks”, Paul B. Stewart and Ernest S.

Starkman, at University of California, WADC Technical Report 55-418, September 1955

2.2. Interviews

Mr. Alankar Gupta, Seattle, WA

Mr. Harley Harmon, Renton, WA

Mr. Elmer Luehring, Cleveland, OH

Mr. Daniel Gonzales Gellert, Sequim, WA

Mr. Jack Bergman, New York, NY

2.3. Presentations (arranged by company)

Mr. Jean Belhache, Aeronautical Sales Manager

Mr. Olivier Vandroux

Air Liquide Advanced Technology Division

Sassenage, France

Mr. Charles Anderson, Standard Systems Group Manager

Mr. Karl Beers, Mechanical Design Engineer

Air Liquide MEDAL

Newport, DE

Mr. Kenneth Susko, Consultant

Elmont, NY

Mr. Victor Crome, Director of Military Engineering

Mr. Robert Demidowicz, Marketing Manager, Life Support Programs

Litton Life Support

Davenport, IA

Mr. Rolf Weiland, Sr. Systems Design Engineer
28 June, 1998

TG3 9

MVE Inc.

Bloomington, MN

Mr. Robert Fore, Chief Engineer

Parker-Hannifin Corporation

Irvine, CA

Mr. Paul Wierenga, Principal Development Engineer

Mr. Randy Hoskins, Director of Advanced Development

Primex Aerospace Company

Redmond, WA

Mr. Haim Loran, President

Mr. Steve Etter, Engineering/Sales Marketing Manager

Valcor Aerospace

Springfield, NJ

The Inerting Task Group gratefully acknowledges the support of all of the named

individuals, their supporting staff, and their companies who provided their time, talent,

and resources to this project.
28 June, 1998

TG3 10

3. Background

3.1. How Inerting Technology Works

Inerting, as applied to aircraft fuel tanks, can be defined as the inclusion of a gas in the

ullage prior to ignition of the vapor that will suppress that ignition, independent of the

fuel air mixture. The gas used can be one that simply reduces the oxygen available for

combustion, such as nitrogen, or one that chemically interferes with the combustion

process, such as Halon 1301.

Although the military has investigated and used many types of inerting systems (and

gasses) the presently available and viable systems all use nitrogen as the inerting gas.

Systems using exhaust gas (B-50), CO2 and dry ice (B-47 and B-36) where used by the

military but discontinued because of technical problems. Systems using flamesuppressing agents (Halon 1301) are presently being used on some smaller military

aircraft. However, the ban on the production of Halon 1301 and the lack of any

replacement agent makes that a nonviable technology for commercial use. Therefore, the

only presently viable and acceptable inerting gas is nitrogen.

Nitrogen inerting works by reducing the oxygen concentration in the fuel tank ullage

below that necessary to support combustion. Literature indicates that at 9% oxygen or

below no reaction will occur in a tank with Jet A fuel regardless of the fuel air mixture or

the ignition energy. Some testing has indicated that for most conditions 10-11% oxygen

levels provides the same level of protection. Oxygen levels above the no reaction level

but below 16% have been shown to provide some protection and reduce the pressure rise

in reactions that do occur.

In order to initially inert a fuel tank with nitrogen, the nitrogen must be introduced into

the tank in such quantity as to reduce the oxygen level below the desired 9%. In order to

maintain an inert tank additional nitrogen must be introduced to counter the oxygen in the

air drawn into the tank due to pressure changes and fuel usage. In addition, dissolved

oxygen in the fuel released into the ullage as the pressure on the fuel decreases must be

diluted with additional nitrogen. In order to minimize the need for additional nitrogen,

systems normally include check valves at the fuel tank vents to maintain a slight pressure

differential to ambient. This minimizes the introduction of air (21% oxygen) during

minor pressure changes. Scrubbing (bubbling nitrogen through the fuel) prior to takeoff

can reduce dissolved oxygen in the fuel.

Present inerting systems require the use of additional nitrogen during flight. The nitrogen

is either loaded prior to flight and stored in liquid or gaseous form onboard, or generated

in-flight by separating the components of air. The liquid nitrogen systems require ground

based refilling at all landing locations, and a cryogenic nitrogen storage vessel onboard.

Additional valving and plumbing is necessary to make sure only gaseous nitrogen enters

the fuel tanks. Onboard inert gas generating systems (OBIGGS) can be of two types, the

molecular sieve or the permeable membrane. Both types of systems require compressed
28 June, 1998

TG3 11

air, usually engine bleed air, and produce a mixture of nitrogen enriched air (NEA) that is

not pure nitrogen (but is usually less than 5% oxygen).

The molecular sieve utilizes a minimum of two beds of oxygen adsorbing medium, such

as zeolite. As air passes through the medium oxygen is adsorbed. Thus, the gas that

passes through is nitrogen rich. That gas is collected and passed on as the bed is back

flushed, with the enriched oxygen gas exhausted overboard. Two beds are used such that

as one is collecting nitrogen enriched gas the other is being cleansed of adsorbed oxygen.

The permeable membrane system is comprised of many very small hollow tubes made of

a material that allows all the constituents of air to pass through more easily than nitrogen.

Air is supplied to the tubing under pressure. Oxygen from the air permeates the tubing

walls and is collected and exhausted overboard. What is left is nitrogen enriched air

(NEA) usable for inerting.

3.2. Why Military Uses This Technology

The US military looks at aircraft vulnerability based on the mission for that aircraft.

Inerting systems are installed on combat aircraft and aircraft likely to be fired upon

during the conduct of its mission. The inerting system is designed to enhance the ability

to survive enemy fire into a possibly explosive fuel tank. Although the military owns and

operates many commercial type aircraft (including Air Force One, a Boeing 747) none of

those aircraft have inerting systems or any other method of explosion protection for the

fuel tanks.

Initial inerting systems, such as on the C5, utilized stored liquid nitrogen. These systems

are heavy and rely on a large ground support system. As technology has advanced, the

OBIGGS systems have become more practical. The system weight and inlet airflow and

pressure to volume of nitrogen produced has vastly improved. All of the recently

designed and installed nitrogen inerting systems have been of the OBIGGS type.

3.3. Military Service Experience and History with this technology

Very little data is available publicly on the effectiveness or reliability of nitrogen inerting

systems presently used on military aircraft. What can be ascertained is that they are very

effective in preventing fuel tank vapor ignition and the reliability (maintainability) is a

problem. Information presented at the Transport Fuel Flammability Conference, October

7-9, 1997 in Washington DC. showed that the major reliability problems were with the

Air Separation Module, ASM Filter and the Compressor. The valves and sensors had a

high degree of reliability. Overall system Reliability was said to be <200 hours between

failures and <100 hours between maintenance. Information presented on the C-5

indicated a similar reliability (maintainability) problem. The main problem on the C-5

was reported as the storage and refrigeration system for the LN2.
28 June, 1998

TG3 12

4. Design Alternatives

There are several possible design alternatives for an inerting system. The various options

are:

1. a self-contained system on the aircraft;

2. a completely ground-based system (no aircraft-mounted equipment);

3. a hybrid system with the distribution pipes on the aircraft and the inert gas supply on the

ground;

4. a hybrid system with the distribution pipes and a small inert gas supply on the aircraft and

a ground-based inert gas supply for initially inerting the fuel tanks.

In addition, the system could be used to inert the body tanks only (center wing tanks and

fuselage-mounted tanks) or all of the fuel tanks.

Also, there are three methods of inerting the fuel tank:

1. “fuel scrubbing”;

2. “ullage washing”;

3. providing inert gas to the tanks as fuel is depleted or during altitude changes.

There are a variety of gases that will inert fuel tanks and a variety of means to produce

those gases. Lastly, there is a system for enriching the ullage above the upper

flammability limit, which will be briefly discussed.

4.1. Self-contained (aircraft-based) system

An aircraft-based system has a supply of inerting gas, regulators to supply the gas to the

fuel tanks at acceptable pressures, and vent check valves to prevent outside air from

diluting the inert gas in the tanks.

The primary advantage to this system is that the fuel tanks will stay inert for most or all

of the flight provided the system can maintain the flow demanded by the aircraft

operation. The primary disadvantages are additional system weight, cost, loss of range

due to the added weight, and loss of revenue because the aircraft can no longer carry as

many passengers or as much cargo.

4.2. Ground-based system

This design alternative involves inerting the fuel at the airport’s fuel storage tanks or with

a mechanism between the fuel trucks and the aircraft. This design is the best for the
28 June, 1998

TG3 13

aircraft because no equipment is added. However, without a supply of inerting gas, air

will eventually enter the aircraft fuel tank and raise the oxygen level so that the fuel tanks

will not be inerted at some time during the flight. The safety of this alternative will be

discussed in section 8.

4.3. Hybrid systems

Another alternative would be to install an inert gas distribution system in the aircraft fuel

tanks and leave the supply of inerting gas on the ground. This reduces the weight impact

on the aircraft compared to an aircraft-based system. Again, without a supply of inerting

gas on the aircraft air will eventually enter the tank and raise the oxygen level so that the

fuel tanks will not be inerted at some time during the flight.

Another alternative is to install the inert gas distribution system and a small inert gas

supply on the aircraft while retaining the inert gas supply on the ground. The concept is

that the ground-based supply of inert gas would be used to inert the fuel tanks during

refueling. During flight the aircraft’s inert gas supply would provide inert gas to the fuel

tanks as the fuel is depleted and during altitude changes. This system could be sized to

keep the fuel tanks inert throughout the flight but it obviously adds more weight to the

aircraft than the ground-based system or the hybrid system above.

4.4. Body Tank or All Tanks

The Working Group’s preliminary findings showed that the wing tanks were less likely to

have a flammable mixture than the body tank. A safety analysis of the historical fuel

system events showed that the wing tanks have demonstrated an acceptable level of

safety and no further improvement is required. (Reference the report by Task Group 1.)

A variation of all of the arrangements in sections 4.1 through 4.3 would distribute inert

gas to the body tank only. This would put the inert gas where it is most needed, simplify

the system, and minimize the cost and weight impact to the aircraft.

4.5. Fuel Scrubbing

Fuel scrubbing uses inerting gas to dilute the dissolved air in the fuel. This could be

accomplished in the aircraft during refueling (Ref. Figure 1), or at the airport storage

tanks when the fuel is delivered from the refinery. The scrubbers would be built in to the

refueling system of the tank (or put inline between the truck and the aircraft) and mix the

inerting gas with the fuel as the tank is filled.

During climb the air in the fuel, which is mostly nitrogen due to the scrubbing, will

evolve out of the fuel to the ullage. This inerts the ullage during climb and for the early

portion of the cruise flight phase. However, the ullage is not inert during refueling, taxi

and takeoff. Refer to Figures 2 and 3.

Scrubbers require a minimum flow in order to work properly. If the flow from the truck

or refinery is too slow then the inert gas will not be mixed into the fuel and it will not be

inerted. The scrubber also adds some pressure drop to the system so more time would be
28 June, 1998

TG3 14

required to fill the fuel tank(s). The primary disadvantage to fuel scrubbing is that it only

works if a tank receives fuel. An empty tank, such as the TWA800 center tank, would

not be inerted. Refer to Figure 4.

Figure 1

Cross Section of Fuel Scrubbing System

Mounted in a Fuel tank
28 June, 1998

TG3 15

Pre-Scrubbing Prior to Takeoff 

Small Transport - Main Tanks 

Short Flight

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250

Time (min)

Ullage Oxygen Concentration (%Vol)

ULLO2-21%

ULLO2-17%

ULLO2-13%

ULLO2-9%

ULLO2-5%

ULLO2-3%

ULLO2-1%

Inert Limit

Altitude

Start of Climb

Top of Climb

Figure 2 – This figure shows the effect of scrubbing the fuel in the wing (main) tanks during refueling. Note that the ullage oxygen

concentration remains at 21% until the start of climb when dissolved nitrogen and oxygen evolve out of the fuel. The oxygen

concentration reaches a minimum (or maximum, depending on initial oxygen concentration) at the top of climb just as the aircraft’s

cruise phase begins. The oxygen concentration then begins to rise (or fall) as the fuel is depleted and ambient air replaces it.

Also, note that if the fuel is not scrubbed during refueling (the ULLO2-17 and -21% line) then the ullage oxygen concentration actually

increases during climb as oxygen evolves out of the fuel. Oxygen dissolves and evolves more readily than nitrogen.

The following legend refers to

ullage oxygen concentration. For

example, ULLO2-21% means

ullage oxygen concentration is

21%, the same as the air we

breathe.
28 June, 1998

TG3 16

Pre-Scrubbing Prior to Takeoff 

Small Transport - Main Tanks 

Medium Flight

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250

Time (min)

Ullage Oxygen Concentration (%Vol)

ULLO2-21%

ULLO2-17%

ULLO2-13%

ULLO2-9%

ULLO2-5%

ULLO2-3%

ULLO2-1%

Inert Limit

Altitude

Initial Fuel Burn from Main Tanks

Start of Climb

Top of Climb

Figure 3 – This figure shows the effect of scrubbing the fuel in the wing (main) tanks during refueling. This differs from the previous figure

because it’s a medium length flight that requires fuel in the body tank (center wing tank) as well as the wing tanks. The center fuel is depleted

before the wing fuel is used so the oxygen concentration remains constant in the wing tanks for a period of time. Note that there is a slight

increase of oxygen concentration right after the start of climb due to evolving oxygen.

The following legend refers to

ullage oxygen concentration.

For example, ULLO2-21%

means ullage oxygen

concentration is 21%, the same

as the air we breathe.
28 June, 1998

TG3 17

Pre-Scrubbing Prior to Takeoff

Small Transport - Center Wing Tank 

Medium Flight

5

10

15

20

25

30

35

40

0 50 100 150 200 250

Time (min)

Ullage Oxygen Concentration (%Vol)

ULLO2-21%

ULLO2-17%

ULLO2-13%

ULLO2-9%

ULLO2-5%

ULLO2-3%

ULLO2-1%

Inert Limit

Start of Climb Altitude

Top of Climb

Figure 4 – This figure shows that scrubbing is not very effective for fuel tanks that have a small amount of fuel because there’s only

a small amount of nitrogen evolution from the fuel compared to the large air volume in the ullage space.

The following legend refers to

ullage oxygen concentration.

For example, ULLO2-21%

means ullage oxygen

concentration is 21%, the

same as the air we breathe.
28 June, 1998

TG3 18

4.6. Ullage Washing

Ullage washing uses inert gas to dilute the air above the fuel. Refer to Figure 5. To be

effective, this can only be accomplished on the aircraft. A truck or cart with inerting gas

would be connected to a distribution system in the aircraft to deliver the inerting gas to

the fuel tanks. Alternatively, an onboard system could provide the inerting gas to the

distribution system.

The primary disadvantage to ullage washing is that it requires more nitrogen to inert the

fuel tank than fuel scrubbing requires. There’s also a potential for fuel tank structural

damage if the source of inerting gas isn’t regulated properly. Ullage washing works well

in tanks with little fuel but is ineffective in tanks that are full of fuel. This is because the

dissolved oxygen in the fuel evolves out during climb and mixes with the inert gas

causing the ullage to exceed a 9% oxygen concentration. A large amount of fuel also

means more oxygen is introduced into the tank as fuel is depleted and raises the oxygen

concentration above the inert level. On the other hand, an empty tank will stay inerted

until descent when the pressure change causes ambient air to enter the fuel tank. Ullage

washing of a tank with a fuel quantity of 25% or less using NEA that contains 5% oxygen

or less will remain inert until descent, provided there is no ventilation of the tank during

operation. Figures 6 and 7 show the effectiveness of ullage washing for a nearly full and

a partially full tank. Figures 8, 9, and 10 show that the combination of ullage washing

and the normal drop in fuel temperature during a flight can help to limit a fuel tank’s

exposure to a flammable, non-inert ullage.

A combination of fuel scrubbing and ullage washing avoids the problem of evolving

oxygen for nearly full tanks. The ullage oxygen concentration decreased during climb.

However, as the fuel is depleted from the tanks the oxygen concentration eventually

exceeds 9% because ambient air replaces the depleted fuel.

Inert Gas

Vent

Figure 5 - Cross-Section of Ullage Washing System
28 June, 1998

TG3 19

Ullage washing combined with normal fuel temperature changes did prove effective. A

statistical analysis combined fuel temperature and flash point, calculated by Task Group

5, with the ullage oxygen concentration that occurs on typical flights in the body (center

wing) tank. This generated a time of exposure to a flammable, non-inert ullage. On

average, the aircraft was exposed less than 1% of the time. Figures 8 and 9 show a

sample of the fuel temperature, flash point, and ullage oxygen concentration for two of

the several thousand flight conditions that were studied. This represents a significant

improvement over present aircraft. The cost of this system will be provided in Section 9.
28 June, 1998

TG3 20

Ullage Washing Prior to Takeoff

Large Transport, Long Flight

Center Wing Tank

0

5

10

15

20

25

30

35

40

45

0 100 200 300 400 500 600 700 800 900 1000

Time (min)

Ullage Oxygen Concetration (%vol)

0 SCF -21%

47 SCF-17%

101 SCF-13%

178 SCF-9%

301 SCF-5%

410 SCF-3%

641 SCF-1%

Inert Limit

Altitude

214.9 ft^3 Initial Ullage

N2 Wash SCF and O2%

Start of Climb

End of Climb

Descent

Figure 6 - Ullage washing has little effect on a tank with a large fuel quantity. Because of the large fuel quantity, a great deal of air

evolves from the fuel during climb into the relatively small ullage space. The nitrogen in the ullage is diluted by the evolving air and

quickly exceeds 9% oxygen.
28 June, 1998

TG3 21

Ullage Washing Prior to Takeoff 

Large Transport, Medium Flight

Center Wing Tank

0

5

10

15

20

25

30

35

40

45

0 100 200 300 400 500 600 700

Time (min)

Ullage Oxygen Concentration (%vol)

0 SCF-21%

517 SCF-17%

1197 SCF-13%

2127 SCF 9%

3619 SCF-5%

7707 SCF-1%

Inert Limit

Altitude

N2 Wash SCF and O2%

2589 ft^3 Initial Ullage

Start of Climb

Top of Climb

Descent

Figure 7 - Ullage washing is quite effective for a tank with little or no fuel (like the TWA800 center tank). The small quantity of fuel

does not evolve enough air to dilute the nitrogen in the ullage. As a result, the tank will remain inerted until descent at which time

ambient air enters the tank through the vent system.
28 June, 1998

TG3 22

Figure 8 Ullage washing on the ground helps to limit exposure to a flammable, non-inert fuel tank. This chart represents an extremely hot

day combined with a very low flash point fuel. The likelihood of this combination is less than 0.005%. Also, the body (center) tank is empty

for this mission.

The chart shows that the tank is flammable for most of the flight because the fuel tank temperature is higher than the flash point of the fuel.

However, the oxygen concentration drops below the inert limit at about 1⁄2 hour into the mission and stays there until descent (at about 5.5

hours in the mission). So the tank is only exposed at the beginning of the mission and for about 15 minutes during descent as shown by the

brown (exposed) line. Most flights would be exposed for an even lesser amount of time.

E ffect of Pre-Inerting Center Tank

Large A ircraft, Sho rt M is s io n

0.0

25.0

50.0

75.0

100.0

125.0

150.0

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

T im e (hours)

Temperature (deg F)

0

2 5

5 0

7 5

100

125

150

Oxygen Concentration (%), Altitude (kft)

F lash Po int (5 % )

Fue l T e m perature in Center Tank (99.9 % )

A ltitude

U llage Oxygen Concentration

Inert Li m it

Exposed (0=Not Exposed, >0=Exposed)

T h is chart shows the effect of pre-inerting 

the center tank by ullage washing co m b ined 

w ith coo ling in the center tank.

On this m ission, the center tank is e m p ty 

and therefore stays hot due to heat fro m the 

a ir conditioning pack. During descent the 

fla m m a b ility lim it decreases so the tank is 

not fla m m a b le but beco mes fla m m a b le 

during descent, 

The tank is inert after about 1/2 hour and 

stays inert until descent.

The resu lt is m in im a l exposure to a 

fla m m a b le, non-inerted fuel tank.

E x tre m e Case: Probab ility of a 

tank this hot and a flash point 

this lo w is 0.005 % or less
28 June, 1998

TG3 23

E ffect of Pre-Inerting Center Tank

Large Aircraft, Short Mission

0.0

25.0

50.0

75.0

100.0

125.0

150.0

0.000 1.000 2.000 3.000 4.000 5.000 6.000 7.000

T i me (hours)

Temperature (deg F)

0

2 5

5 0

7 5

100

125

150

Oxygen Concentration (%), Altitude (kft)

F lash Point (50 % )

Fue l Tank Temperature (50%)

A ltitude

ullage Oxygen Concenctration

Inert Lim it

Exposed (0=Not Exposed, >0=Exposed)

Average Case: Fuel 

t e mperature and flash point 

probabilities are 50% .

Figure 9 Ullage washing on the ground limits exposure to a flammable, non-inert fuel tank essentially to zero probability. This chart

represents an average day combined with an average flash point fuel. The body (center) tank is almost filled for this mission.
28 June, 1998

TG3 24

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28 June, 1998

TG3 25

4.7. Inert Gas Supply

Several methods of supplying inerting gas were presented to the task group. Most of the

methods used nitrogen, but carbon dioxide and exhaust gas were also presented.

4.7.1. Nitrogen

There are three types of nitrogen supplies: liquid nitrogen in Dewar bottles, gaseous

nitrogen in high-pressure storage bottles, and gaseous nitrogen extracted from engine

bleed air as mentioned in Section 3.1. Some of this technology exists while some of it is

still in development.

Liquid nitrogen and gaseous nitrogen in storage bottles both require servicing at the

airport to refill them. The on-board inert gas generating system (OBIGGS) does not

require refilling but does require periodic maintenance and filter changes.

The two types of OBIGGS available presently are molecular sieve and permeable

membrane. Molecular sieve systems have been in use since 1975 on various military

aircraft. Molecular sieves adsorb oxygen from the air and can operate with source air

pressures as low as 20 psig and temperatures between –20 oF and +120 oF. They are

sensitive to liquids however and may need to be replaced if wetted. The adsorbed oxygen

must also be flushed from the sieve at regular intervals. In operation, this means that two

molecular sieves must be available and a valve cycles the source air between them to

maintain a constant flow of inerting gas.

By contrast, permeable membrane systems are completely passive. They rely on the

polymer membranes to separate nitrogen from air. These systems have been in

commercial use since 1975 but have only recently been applied to aircraft. Permeable

membranes work best with source air pressures of 60 psig and temperatures near 140 oF.

A reduction of source air pressure to 30 psig would require approximately 3 times more

membrane material to maintain the same output flow. A reduction to 15 psig would

require 10 times more material. Thus, the system weight and its impact on the aircraft are

sensitive to the source pressure.

Permeable membranes are also sensitive to source air flow. More source air is required

to provide better purity (lower oxygen concentration). Three times more source air is

required to achieve an oxygen concentration of 3% than for an oxygen concentration of

9%. The impact on aircraft resources can be minimized if a higher oxygen concentration

can be permitted. Contaminates that could plug the membrane material would also

require more bleed air to get the same effectiveness as an unplugged membrane.

4.7.2. Carbon Dioxide

There are three types of carbon dioxide (CO2) supplies: solid CO2 kept in cold storage

(dry ice), gaseous CO2 in high-pressure storage bottles, and products of combustion. The
28 June, 1998

TG3 26

dry ice and gaseous CO2 in bottles require servicing at the airport. Servicing for the

combustion system is dependent on whether fuel or carbon is burned. Carbon

combustion would require frequent servicing. Fuel combustion would likely require only

periodic maintenance for filter changes, etc. These systems are conceptual at this time

although dry ice was tried briefly in the 1950s.

It takes less carbon dioxide than nitrogen to inert a fuel tank. However, carbon dioxide

dissolves into solution and evolves out of solution more readily than nitrogen.

Consequently, fuel boost pump cavitation may occur because of altitude changes,

pressure loss in fuel pipes or any other event that causes pressure changes. However,

carbon dioxide was not pursued further in this study because it is a greenhouse gas that

adversely affects the environment. Its use might be subject to future environmental

restrictions or banned completely. Therefore, a more detailed study would be required to

determine the feasibility of carbon dioxide as an inerting agent.

Due to the lack of hardware and test data required to complete a cost/benefit/feasibility

analysis, this solution was not evaluated for this report.

4.7.3. Exhaust Gas

The use of exhaust gas was suggested as a means to inert the fuel tanks without adding

bulky storage systems to the aircraft. The system would be self-contained and would

likely only require periodic maintenance for filter changes. This is a concept only. There

is presently no technology to evaluate at this time. Therefore, it was not considered

further for cost, benefit, or feasibility in this report. However, there are some concerns

with the concept.

Jet engines and auxiliary power units (APUs) do not burn fuel at a stoichiometric mixture

ratio. They burn the fuel leaner than stoichiometric so that the exhaust gas is higher in

oxygen than the typical combustion process. The oxygen level can range from 11% to

15% depending on the power setting for the engine and other factors. These levels are

too high to be considered inert.

The exhaust stream of commercial aircraft engines is primarily ambient air due to the

high fan-bypass ratio of these engines. This air contains 21% oxygen and is not inert.

The lower oxygen concentrations (11-15%) must be drawn from the turbine section

directly, or very close behind it, to avoid the fan bypass air. This section of the engine is

typically at 1000 oF or higher and special materials are required to withstand the heat.

Any penetration of the turbine case to install a bleed line would weaken the turbine case

and increase the chance of engine damage from temperature stresses and vibration. Recertification would be required to install a bleed line in the turbine case for existing

engines and the cost would likely be prohibitive. A failure of the bleed line would create

an unacceptable hazard to the aircraft.

Although the autoignition temperature of fuel is 450 oF, the exhaust gas must be cooled to

160 oF or less before it can be introduced into the fuel tank to protect components, fuel

tank sealants, protective coatings, and fuel bladders. A large precooler would be required
28 June, 1998

TG3 27

to reduce the gas temperature from >1000 oF to < 160 oF. Most transport aircraft have

their engines mounted on the wings near the fuel tank so the location of a precooler is

limited to the engine or engine pylon. On many aircraft, the addition of a larger, or an

additional, precooler is not feasible due to space limitations in the pylon area. Other

locations, such as the cargo compartment or the fuselage area could also be difficult due

to space limitations and the need to provide outside cooling air to the precooler. This

would require a duct and two air scoops on the side of the aircraft that add to the drag.

Another concern is a high concentration of water vapor in jet engine exhaust that would

have to be removed before reaching the fuel tank. This is not desirable as water causes

tank corrosion, promotes the growth of microbes in the fuel, and possibly would freeze at

high altitude and block fuel pump inlets. Aircraft manufacturers design to avoid water in

fuel tanks and the airlines perform frequent ground checks to make sure water is removed

from the tanks before flight. Anything that adds water would require more systems

and/or more frequent checking to avoid these problems.

There is also a fuel burn penalty for using exhaust or turbine gas. Turbine gases

contribute to the energy needed to drive the engine fan to produce thrust. Exhaust gases

expand and help to produce thrust. If some of the gas is diverted for other purposes then

there is less thrust. The throttle setting must be increased to make up for the loss of thrust

so more fuel is consumed. The estimated fuel penalty would be 5-10%.

Finally, there are contaminates in the exhaust gas that would have to be filtered prior to

being introduced into the fuel tank. This would add to the size, cost, weight and

maintenance of this method. There is a concern about the corrosive effects of the oxides

of nitrogen and sulfur in the exhaust gases on the fuel system and tank. Filters would

have to be maintained and a monitoring program would be required to avoid adverse

affects to the fuel tank.

4.7.4. Fuel Enrichment of the Ullage

This concept atomizes fuel in the ullage space of the tank providing an atmosphere that is

too rich for combustion. A pump would be energized when a tank sensor determined that

the ullage might be combustible. The tank could never be emptied because there

wouldn’t be any fuel to atomize into the ullage. The minimum fuel volume within a tank

could not drop below 10% of the tank volume. This is a concept only. There is presently

no technology to evaluate at this time. Therefore, it was not considered further for cost,

benefit, or feasibility in this report. However, there are some concerns with the concept.

The primary concern for this system is that it could increase the severity of a post-crash

fire if the tank was damaged. It’s also unclear if the sensor would deteriorate due to

aging, how it predicts flammability, and what effect fuel slosh would have on it.
28 June, 1998

TG3 28

5. Installation Requirements

Ground-based fuel tank inerting consists of fuel scrubbing and ullage washing. Aircraftbased inerting consists of these same methods plus supplying inert gas to the tanks as fuel

is depleted and/or during descent.

5.1. Installation of Ground-Based Inert Gas Supply

A ground-based inerting system requires a source of inerting gas at the airport. The most

likely sources are liquid nitrogen or gaseous nitrogen produced by an air separation plant

similar to, but larger than, the air separation equipment previously discussed. There are

several manufacturers of air separation plants that may be willing to install a plant for

free because their profit is obtained by selling the nitrogen to the airport’s customers

(airlines). The gaseous nitrogen could then be delivered to the aircraft by truck or by a

pipeline between the plant and the terminal buildings. Another possibility would be

portable air separation plants on trucks that could drive up to the aircraft prior to

refueling.

Liquid nitrogen would probably have to be trucked into the airport storage area. The

liquid nitrogen could then be delivered to aircraft by a separate truck or by a pipeline

between the storage facility and the terminal buildings.

Figure 11 shows a typical airport arrangement. The fuel farm is located far from the

terminal buildings. In this case, the distance from the fuel farm to the farthest terminal

building is approximately 2 miles. The most likely location for a nitrogen storage facility

is near the fuel farm. A pipeline from the nitrogen storage facility to the terminal

buildings is a major construction project at most airports and will likely disrupt

operations if the runways, taxiways or ramps have to be torn up to add the pipeline.

A better solution for the airport would be to scrub the fuel as it is delivered from the

refinery. The inerting gas plant could be located nearby to provide nitrogen directly to

the scrubbers with less disruption to the airport operations. However, this would still be a

major change to the airport’s fuel storage facility and could disrupt fuel delivery to the

airlines during installation. In addition, fuel scrubbers decrease the flow rate into the fuel

tanks, as previously discussed. At a time when refineries can barely keep up with current

demand, due to the limitations of delivery pipelines between the refineries and the

airports, this could have severe consequences for the airlines.

Another option is to deliver the nitrogen to the terminal with trucks. An additional truck

near an aircraft at the terminal increases the risk of accidents with potential damage to the

aircraft. If the trucks are carrying liquid nitrogen then there is an additional risk of

spilling it on aircraft or people.
28 June, 1998

TG3 29

Figure 10 - Typical Airport Layout
28 June, 1998

TG3 30

The last option considered is to place small nitrogen generation units at each terminal.

The effect on airport operations would probably be less than that caused by running a

pipeline from a central nitrogen unit. Unit installation could be phased to minimize the

impact on terminal gate operations. However, the economies of scale would probably not

be realized and the overall cost might be equal to or greater than a central unit.

No attempt was made to estimate the cost impact of adding a nitrogen storage or

generating facility to an airport’s infrastructure. This would have required reviewing the

layout of several hundred airports to determine the most likely location for the facility,

the cost of construction in the local area of each airport, local building codes, etc. An

attempt was made to estimate the cost of trucks carrying nitrogen from the storage facility

to the terminal buildings. A basic assumption was that there would be one nitrogen truck

for every fuel truck at the airport.

5.1.1. Ground-based scrubbing

Ground based scrubbing occurs during aircraft refueling or during the filling of the

airport’s fuel storage tanks. This can be accomplished in one of three ways: scrubbing

the fuel as it comes from the refinery into the airport storage tanks or from the airport

storage tanks to the airport fuel pit/trucks; scrubbing the fuel during refueling of the

aircraft using a ground-based scrubber; and scrubbing the fuel during refueling using an

aircraft-based scrubber. The first method, scrubbing the fuel as in enters the airport

storage tanks or fuel pit/truck, does not require any aircraft equipment but requires

modifications to the airport infrastructure or fuel trucks. The second method also does

not require aircraft modification but requires that a device be coupled to the fuel pit/truck

and that a source of inerting gas be available. The third method requires that fuel

scrubbers be added to the aircraft and a supply of inerting gas be available during

refueling.

5.1.2. Ullage Washing

Washing the tank ullage with nitrogen would require aircraft modifications to include a

servicing/supply port, check valve, isolation valves and a distribution system. The

servicing/supply port provides a means for introducing nitrogen into the aircraft tank(s).

The distribution system provides nitrogen to vented tanks or incorporates isolation valves

to selected tanks. Vent box mounted check or climb/dive valves prevent ambient air

from diluting the nitrogen in the fuel tanks. The check valve prevents fuel from exiting

the nitrogen servicing port.

Although the installation of ullage washing components would be similar for all aircraft,

distribution systems will vary according to the fuel tank size and location on the aircraft.

Distribution systems on aircraft with non-traditional tanks, e.g. tail tanks, would require

more elaborate distribution systems. Ullage washing does not require any fuel delivery

modifications, but would require minor airframe modifications.

5.2. Installation of Aircraft-Based Fuel Tank Inerting

5.2.1. Overview
28 June, 1998

TG3 31

Aircraft inerting systems will require extensive aircraft modifications. Aircraft inerting

systems require the same equipment as the hybrid system plus a means of inert agent

development, inert agent storage, and possibly indication systems and oxygen sensors.

With the exception of inert agent generation, all aircraft inerting systems are principally

the same. The currently viable technologies are nitrogen storage and air separation.

Future possibilities may include exhaust gas and CO2.

5.2.2. Air Separation

Permeable membranes and molecular sieves both require a conditioned air source to

develop the nitrogen enriched air. Currently, the only air source available in flight is

engine bleed air.

On medium and large aircraft, bleed air could be obtained from either existing pneumatic

systems or the ECS systems. Many smaller turboprop aircraft simply do not have

sufficient bleed air available to spare; therefore, small transport aircraft would require an

additional source separate from the engine to supply bleed air.

Present day aircraft are optimized for certain flight regimes and their systems are highly

integrated. Engine bleed air is used by the environmental control system to pressurize the

cabin and by the anti-ice system to minimize wing and tail icing. Under some flight

conditions, such as takeoff or descent, all of the engine bleed air is used for existing

aircraft equipment. There isn’t any more available to supply OBIGGS systems. This was

found to be the case for four of the six generic airplanes studied. (Data was not available

for the other two aircraft types.) The suppliers assumed an ullage washing system and a

gas purity of 9% for their calculations but the lack of bleed air prevented the OBIGGS

systems from supplying inert air to the fuel tanks throughout the flight profiles.

5.2.3. Exhaust Gas

While the Task Group does not believe that this technology is currently viable, it may be

of value to aircraft designers in the future.

The collection of engine exhaust gas would require the installation of a bleed air port

within the engine’s turbine stage(s). Since nearly all engines use fan air to assist in

cooling the engine’s turbine, the location of the bleed air port would have to be properly

located to avoid the fan air. Tapping into an existing engine turbine stage would require

extensive and costly engine re-work and re-certification.

Adding to the complexity of installing an exhaust bleed-air port, engine exhaust systems

will require conditioning, filtering, overheat protection and a distributing system. For

estimating purposes, existing ECS systems could provide a minimum baseline for

determining the size and cooling requirements of an engine exhaust system.

Engine exhaust gas contaminates include high levels of sulfur, nitrogen, oxygen, water,

carbon dioxide, hydrocarbons and other engine ingested chemical compounds. These
28 June, 1998

TG3 32

contaminates must be filtered to avoid introducing corrosives into the fuel tanks and the

resultant structural integrity inspections that would be required.

5.2.4. Combustion (Carbon Dioxide) Systems

While the Task Group does not believe that this technology is currently viable it may be

of value to aircraft designers in the future.

Combustion systems are currently in the concept or prototype stage of development. The

following description is based on the information provided to the Task Group by a

supplier of a prototype system.

Combustion inerting systems require that a combustion process occur to develop carbon

dioxide (CO2) which is used as the inerting agent. To support the combustion process, a

combustion chamber is required which operates at extremely high temperatures and

appears to be large in size and shape. The hot CO2 would be cooled to the required

temperature using air-to-air heat exchangers and a source of cool air. These systems

must be treated as a fire hazard, which requires they be located in existing fire zones or

that a fire zone be created specially for them. A combustion system could be frugal with

aircraft resources requiring little power or bleed air for operation.

5.2.5. Cryogenic Systems

Cryogenic inerting systems require a system reservoir to store liquid agent. Sizing of

reservoirs is dependent on aircraft application and is sensitive to changes in external

pressures and temperatures.

Due to pressures and temperatures within the vessel, containment vessels tend to be very

large and bulky. Although larger aircraft could accommodate these vessels, smaller

aircraft might not so easily accommodate them. Also, to accommodate these vessels,

aircraft will require extensive airframe structural modifications and/or analysis to insure

the airframe’s integrity.

5.3. Installation Requirements for All Inerting Systems

5.3.1. Ground-based Systems

Installation of ground based inerting systems at a minimum will require approximately 51

man-hours over an elapsed time of 70-75 hours. Table 1 summarizes total expected

installation effort to inert the center wing tank.
28 June, 1998

TG3 33

Table 1 – Installation Time for Ground-Based Center Tank Inerting System

Small Aircraft Medium Aircraft Large Aircraft

BASIC SYSTEM REQUIREMENTS Hours Men Hours Men Hours Men

Drain Tanks 1 2 1.5 2 2 2

Open Tanks 1 2 1 2 1 3

Purge Fuel Tanks 24 1 24 1 24 1

Install Quick Disconnect 4 2 1 2 1 2

Install Check Valve 2 1 1 1 1 1

Install Regulator 2 1 2 1 2 1

Install Indication System 7.5 2 7.5 2 7.5 2

Install Climb/Dive Valve 6 2 6 2 6 2

Test System 2 2 2 2 2 2

Close/Seal tanks 1 2 1 2 1 3

System Leak Check 2 2 2 2 2 2

TOTAL INSTALLATION ELAPSED TIME 50.5 51 51.5

TOTAL INSTALLATION MANHOURS 71 72 75

5.3.2. Aircraft-based Systems

All aircraft inerting systems may require an indication system in the cockpit and at the

servicing location. Cockpit indication provides for crew monitoring while servicing

location indication provides for maintenance monitoring. Indication systems will vary in

complexity based on the type of inerting agents used and the arrangement of the fuel

tanks to be inerted. Indicating systems would warn crews and/or maintenance personnel

of the loss of system operation and any degradation of function. Indicator sizing

requirements are comparable on all fleet types but would be more restrictive on smaller

transport aircraft due to limited space within cockpits.

Installation of aircraft inerting systems at a minimum will require approximately 60 manhours over an elapsed time of 150 hours. Smaller aircraft would require smaller

distribution systems, but may require additional installation time for components since

accessibility and spacing are at a premium. Engine bleed air and/or engine exhaust

systems would add 15 man-hours per engine exclusive of any engine re-work, if

necessary. Reservoirs and indication systems will add 30 and 15 man-hours respectively.

Tables 2, 3 & 4 provide estimates of installation effort.

Table 2 – Installation Time for Aircraft-Based OBIGGS System (All Tanks)

Small Aircraft Medium Aircraft Large Aircraft

AIR SEPARATION TECHNOLOGY Hours Men Hours Men Hours Men

Basic Effort (Above) 71 ----- 72 ----- 75 -----

Module Installation 15 2 15 2 15 2

Engine Bleed/Exhaust Collection 7.5 2 7.5 2 3.75 4

Bleed/Exhaust Conditioning and

Distribution System

4 2 6 4 12 6

Filtration System 2 2 2 2 2 2

TOTAL ELAPSED TIME 60.5 61 61.5

TOTAL MAN HOURS 127 144 196
28 June, 1998

TG3 34

Table 3 – Installation Time for Aircraft-Based Combustion System

Small Aircraft Medium Aircraft Large Aircraft

COMBUSTION TECHNOLOGY Hours Men Hours Men Hours Men

Basic Effort (Above) 71 ----- 72 ----- 75 -----

Combustion Vessel 15 2 15 2 15 2

Distribution System 3 2 5 2 8 2

TOTAL ELAPSED TIME 60.5 61 61.5

TOTAL MAN HOURS 107 112 121

Table 4 – Installation Time for Aircraft-Based Cryogenic (Liquid Nitrogen) System

Small Aircraft Medium Aircraft Large Aircraft

CRYOGENIC TECHNOLOGY Hours Men Hours Men Hours Men

Basic Effort (Above) 71 ----- 72 ----- 75 -----

Cryogenic Vessel 15 2 15 2 15 2

Distribution System 3 2 5 2 8 2

TOTAL ELAPSED TIME 60.5 61 61.5

TOTAL MAN HOURS 107 112 121
28 June, 1998

TG3 35

6. Technical Data

The following data provides estimates of the impact of the various systems on the generic

aircraft that formed the basis of this study. Several suppliers spent long hours analyzing

the generic aircraft data and sized their systems accordingly. The suppliers based their

estimates on an analysis of the various generic aircraft, specifically their fuel volume,

mission length, starting fuel volume, engine bleed performance, climb and descent rates,

and the setting of the vent check valves that keep ambient air out of the fuel tanks.

6.1. Weight

The following weights, in Table 5, are a composite of the weights estimated by various

suppliers of air separation modules. The suppliers assumed that at least 30 psig to 60

psig of engine bleed air would be available at the necessary flows and that the bleed air

would be cooled to an acceptable temperature for the module. Ullage washing was

assumed, which requires less purity of the nitrogen and minimizes the bleed air

requirement. This system was intended to inert all fuel tanks on the aircraft.

Because of the lack of available bleed air on present day aircraft and the resulting lack of

inerting during some phases of the flight profile, OBIGGS systems are not considered a

viable option for incorporation into existing aircraft or for retrofit. Therefore, there is no

air separator weight estimate for present day aircraft or for those requiring retrofit.

The additional system weight consists of precoolers to cool the engine bleed air for the

air separator modules, fans to blow cool air over the precoolers during ground operations,

water/dust separators to avoid contaminating the air separation modules, valves to control

flow to the tanks and to shut off some of the air separator modules during cruise (when

only “make up” gas is required to replace depleted fuel), a distribution system, pressure

sensors, pressure regulators, oxygen sensors, and vent check valves.

Table 5

Future Aircraft Air Separator Technology Weight

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Module

Weight

(lbs.)

805 408 158 134 110 173

Additional

System

Weight

(lbs.)

1547 941 558 522 486 581

Total

Weight

(lbs.)

2352 1349 716 656 596 754
28 June, 1998

TG3 36

For present day aircraft and those requiring retrofit, a system that does not require bleed

air is a better match for the aircraft. However, they carry the penalty of higher weight

than the air separation technology. The following estimate, in Table 6, is based on a

liquid nitrogen storage system sized to inert all fuel tanks on the aircraft.

The additional system weight consists of a distribution system, fuel scrubbers, pressure

sensors, pressure regulators, oxygen sensors, electrical wiring, mounting hardware, finish

installation cover panels, and vent check valves. Since this installation had not been

previously analyzed, the additional system weight for the air separator technology was

semi-arbitrarily divided by two for this estimate. For this estimate, fuel scrubbing and a

“make-up” system were assumed since this requires less nitrogen than ullage washing.

(A “make-up” system replaces the consumed fuel with inert gas instead of letting ambient

air replace the consumed fuel.) This assumption is valid since liquid nitrogen is pure i.e.

it contains no oxygen.

Table 6

Present Day Aircraft Liquid Nitrogen Technology Weight

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

LN2 Weight

+ Storage

Vessel &

Controls

(lbs.)

1611 765 230 179 128 262

Additional

System

Weight (lbs.)

774 642 558 551 543 564

Total Weight

(lbs.)

2385 1407 788 730 671 826

6.2. Size (cargo/passengers/fuel displaced)

The suppliers of air separation modules have only grossly estimated the approximate size

of their module package. The largest would occupy the equivalent of a cube that is 5 feet

on each side while the smallest would be approximately 14 inches on each side. Due to

the severe time constraint imposed by the FAA for this study, the Task Group has been

unable to determine the size of the additional equipment needed to mount the air

separator modules and cool the engine bleed air to acceptable levels. It is probable that

the package would be double the size of the module package and displace some cargo, as

the cargo compartment is the most likely location for mounting this equipment.

Therefore, no cost will be associated with this item and the Task Group will assume that

it is somewhat compensated by the weight penalty listed in section 6.1 and it’s associated

costs listed in Section 9.
28 June, 1998

TG3 37

6.3. Cost

The following module costs, in Table 7, are a composite of the costs estimated by various

suppliers of air separation modules. The costs quoted are for a shipset of modules where

a shipset has the capability to inert all fuel tanks on the aircraft. Design and installation

costs will be discussed in Section 9.

Table 7

Future Aircraft Air Separator Technology Cost

Shipset Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Modules $606,000 $304,000 $113,000 $95,000 $77,000 $125,000
28 June, 1998

TG3 38

7. FAA Certification Requirements

7.1. Similarity/Previous Test or Flight Experience

There is no previous test or flight experience in commercial aircraft. In addition, it is not

yet clear what regulations might be enacted by the FAA for the certification of fuel tank

flammability reduction systems. Thus, the certification requirements and costs cannot be

estimated at this time.

7.2. Additional Analysis and Testing

Analysis and testing is dependent of the regulation. Since it is not yet clear what

requirements might be enacted by the FAA, the Task Group cannot estimate the

certification requirements or costs to comply with the new regulation. However, there

are existing requirements for the certification of aircraft systems that would be expected

to apply to inerting. The costs to comply with the existing requirements are shown as

part of the design cost in Section 9.

7.3. Other Effects on Aircraft

All of the systems add substantial weight to the aircraft. Some existing aircraft could be

re-certified for the additional weight allowing the airlines to carry the same payload as

they currently do. However, there will be some impact on operations resulting from the

increased weight. Runway lengths for takeoff and landing will increase slightly. Fuel

costs will increase also and these are estimated in Section 9.

All of the proposed systems utilize a vent check valve to keep the inert gas in the tank

and to delay the introduction of ambient air. By holding inert gas in the tank during

climb and cruise, the vent check valves cause the wing to become slightly pressurized.

By keeping ambient air out of the tank during descents, the vent check valves allow the

tank to be slightly compressed by outside air. The fuel tank structure may have to be recertified to show that it still complies with all strength requirements imposed by the FAA

due to the change in loads.

Air separation technologies may be viable for some aircraft that can supply the required

engine bleed air. This may require re-certification of the engine by the engine

manufacturer and re-certification of the aircraft by the aircraft manufacturer to show that

the additional bleed air requirement does not adversely impact engine operation and

aircraft performance. In addition, it is possible that during certain phases of the flight the

loss of an engine and its bleed air may require operational changes. For example, the loss

of one engine’s bleed air on a twin may require choosing between pressurizing the cabin

or inerting the fuel tanks.
28 June, 1998

TG3 39

8. Safety

8.1. Effectiveness in Preventing Overpressure Hazard

Military, live-fire testing has demonstrated that nitrogen inerting prevented catastrophic

tank over pressures with an ullage oxygen concentration from 12% [1] and 10% [2] at sea

level for up to 23mm high energy incendiary (HEI) rounds. The military has adopted 9%

oxygen concentration as the inert limit. Laboratory testing showed that inert limits for

combustion increased with altitude from less than 10% to over 13% oxygen concentration

from sea level to 60 kft [3]. Since the 9% oxygen concentration limit prevents tank overpressures for energetic ignitions sources up to 23mm HEI rounds, this would also protect

against any internal threats from within intact commercial aircraft fuel systems.

However, in events where the fuel system has ruptured from other causes allowing air to

enter the fuel system or fuel to leak, nitrogen inerting may not prevent fuel fires or

explosions inside or outside the fuel system.

8.2. Evaluation against Historical Commercial Aircraft Overpressure Events

The list of commercial aircraft over-pressure events is presented in Table 1. An

evaluation of the effectiveness of a full time inerting system is also shown in Table 1,

assuming the inerting system was functional and the entire fuel/vent system was inerted

at the time of the incident. Inerting may not have prevented catastrophic results in all of

the events where the fuel tanks were open or had been open for maintenance or ruptured

from other causes. These are the engine separation events (3,4, and 5), the 727 sabotage

event (6), and ground maintenance events where the tanks were open or had been opened

(13 and 14). The evidence in the727 bomb-sabotage event (6) suggested that the force

caused by the bomb blast compromised the structural integrity in this area, causing a fuel

tank rupture, fire, and in-flight structural breakup of the right wing. Whether, the initial

bomb blast would have caused a hull loss without the subsequent fire is not known. Also,

it is not known that if had the fuel tank been inerted if the subsequent fire would have

occurred. Therefore, we can only conjecture whether inerting would have prevented a

hull loss in this sabotage event.

Inerting could have prevented the catastrophic results in all of the remaining events, the

lightning strikes (1 and 2), refueling events (9-12), the TWA and PAL CWT events (7

and 8), and the DC9 ground maintenance event (15).
TG3 40

Table 8

Evaluation of Effectiveness of Inerting For Historic Fuel Tank Explosion Events

Operational Phase Ignition Source

No. Year – airplane Inflight Ground Ops Ground

Maint.

Refueling Lightning Overwing

Fire -

Inflight

Static

Discharge

Sabotage Unkno

wn

Could Inerting1

have prevented

catastrophic

outcome?

1 1963 – 707 X x Yes

2 1976 – 747 X x Yes

3 1965 Eng Sep 707 X x No

4 1970 Eng Sep DC8 X x No

5 1992 Eng Sep 707 X x No

6 1989 - 727 Sabotage X x Unknown

7 1996 - 747 TWA X x Yes

8 1990 – 737-300 PAL X x Yes

9 1970 – 727 x x Yes

10 1970 – 727 x x Yes

11 1973 – DC8 x x Yes

12 1989 – Beech 400 x x

2 Yes

13 1967 – 727 x x No

14 1974 – DC8 x x No

15 1982 – DC9 x x

3 Yes

1

 Assuming fuel/vent system was inert at the time of the incident

2

 Static charge generated by non-conductive foam in another tank

3

 Suspect Dry Running Boost Pump
28 June, 1998

TG3 41

8.3. Negative Impacts

The impacts to the aircraft have been previously covered in Sections 4 and 5.

8.4. Increased Landings due to Range Reduction (due to added system weight)

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report.

8.5. Increased Landings due to Extra Fuel Consumed

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report.

8.6. Personnel Hazards

All inerting systems are designed to minimize the accumulation of oxygen in a confined

space. Nearly all inerting systems produce environments hostile to humans. In all cases,

a person will lose consciousness if exposed to an inert atmosphere. Death is possible if

the person cannot be removed from the inerted fuel tank within a few minutes.

Liquid nitrogen systems require the cryogenic transport and/or storage of nitrogen in

liquid form, which boils at -195 °C or -315 °F. Transport, storage and handling of

liquid nitrogen requires precautions to prevent severe skin burns upon contact.

Gaseous nitrogen systems lessen the burn risk associated with liquid nitrogen. However,

the pressurized containers present a hazard. A broken bottle or distribution line can flood

the compartment with nitrogen causing asphyxiation. The high pressure gas escaping the

bottle or line could injure someone nearby. And if the storage bottle mounting hardware

was loosened, to change the bottle for example, the bottle could move rapidly and injure

someone.

Like liquid nitrogen, carbon dioxide generators using dry ice pose the same threat of

severe skin burns and asphyxiation.

Combustion systems that produce carbon dioxide and exhaust gas inerting systems

operate at high temperatures. There is a potential for severe burns while servicing the

equipment.

All types of inerting systems will require almost daily interaction with maintenance and

other ground personnel of all cultures and education levels. Inerting system dangers will

grow proportionally with the desire to launch an aircraft, and mistakes will be made.

8.7. Aircraft Hazards or Effects

Fuel tank inerting adds additional threats to aircraft from additional system complexity,

pressure vessel ruptures and failure modes that may impact other systems.
28 June, 1998

TG3 42

Inerting systems using heat also pose threats. Burn chambers/engine exhaust systems

expose aircraft and occupants to the threat of extreme heat if unconfined. Besides the

obvious threat of fire, structural airframe damage is also possible. Airframe structure

heated beyond design limitations loses strength, which is not apparent to visual

inspections. With temperatures nearing 900°F for chambers and 1000°C for engine

exhaust, system failures could easily start a chain reaction resulting in hull loss with little

warning.

Aircraft weight and balance must also be considered for all aircraft inerting systems and

will vary with aircraft size and system size.

8.8. Other Equipment Hazards or Effects

Equipment required to support inerting systems also pose threats. Ground support

equipment will require maintenance and testing to verify proper operation. The same

threats that could occur on the aircraft are possible with ground support equipment

Existing airport gate and ramp space is already congested with numerous types of support

equipment. Each piece of new equipment introduced in the airport ramp areas increases

the likelihood of accidents. Accidents involving cryogenic vessels will dramatically

increase the severity of injury to ground personnel and aircraft and/or equipment.

Waste products associated with the combustion type inerting systems require the disposal

of burned carbon. Due to the high temperatures, there is a threat to the aircraft, personnel

and storage facilities during removal of hot waste product. Exposing the airport ramp

environment to the hot waste product could be comparable to an open flame in the area.

Generally, open flames are kept at least 50 feet from the aircraft. A combustion system

will require careful design to eliminate these hazards.

The production of CO2 is also an environmental concern as a “green-house” gas. The

Environmental Protective Agency (EPA) has successfully lobbied for the passage of

numerous clean air acts. The EPA’s vigilance in preventing “green-house” gases may

prevent or severely restrict the use of this technology.
28 June, 1998

TG3 43

9. Cost Impact

9.1. Retrofit

9.1.1. Air Separator Technology

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report.

9.1.2. Liquid Nitrogen Technology

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report.

9.1.3. Simple Hybrid System

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report.

9.2. Current Aircraft

9.2.1. Air Separator Technology

Air separator technology requires more bleed air than is available from present day

aircraft. Therefore, this technology is not considered viable and no costs are provided for

current aircraft. However, the cost of this technology for future aircraft has been

estimated in section 9.3.

9.2.2. Liquid Nitrogen Technology – All Tanks

The following liquid nitrogen storage bottle costs were provided by the suppliers. The

other costs are scaled from estimates made by Boeing for the OBIGGS system in the

industry response (July 1997) to the FAA Request for Comment. This system includes

check valves, distribution pipes, pressure regulators, control orifices, pressure sensors,

and climb/dive check valves.

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report, so they are left blank. The system was assumed to be installed only

on aircraft with heated body tanks and provides inerting for all tanks. The Task Group

was not able to determine if the Regional Turbofan and Turboprop had heated body tanks

for this analysis. Therefore, the cost estimate for these aircraft is unknown.
28 June, 1998

TG3 44

Table 9

Present Day Aircraft with Heated Body Tanks, Liquid Nitrogen Technology, Nonrecurring Costs

Fleet Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

LN2 Bottle $31,306 $16,600 $7,269 $7,111 $5,287 $

Design $34M $32.7M $31.9M $31.8M $31.7M $31.9M

Installation $3.9B $3.3B $18.9B $2M $1.5M $1.2M

Operational

Maintenance

Infrastructure

Range Lost

Total Cost $3.94B $3.36B $18.9B Unknown Unknown 0

# of Aircraft 1280 1092 6192 Unknown Unknown 0

Cost per

Aircraft

$3.0M $3.1M $3.1M Unknown Unknown 0

There is also a penalty to the aircraft due to the added weight of the system. In most

cases, the added weight merely results in extra fuel consumed to travel the same distance.

However, if the aircraft is at its maximum weight limit then some passengers cannot be

carried in order to put in the extra fuel. This results in an additional penalty for lost

revenue and appears in the row labeled “Long Mission” where the aircraft is the most

full.

Table 10

Present Day Aircraft with Heated Body Tanks, Liquid Nitrogen Technology,

Annual Recurring Costs

Due to Added System Weight

Annual

Fleet Cost

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

$423.6M $138.0M $244.3M Unknown Unknown $1.2M

In addition, liquid nitrogen would have to be transported to the aircraft at each refueling.

This incurs costs at the airport to maintain a supply of liquid nitrogen, the means to

transport it to the aircraft, and the training of personnel to handle it. For this estimate,

trucks of liquid nitrogen were assumed as the means of transport for the reasons listed in

Section 5.1. The Task Group was not able to define all of the cost impacts due to the

limited time frame for the report, so they are left blank.
28 June, 1998

TG3 45

Table 11

Airport Costs for Liquid Nitrogen Technology

Non-recurring

Nitrogen Trucks $3.3M Assumes 20 per airport

O2 Detectors $16,500 Assumes 22 per airport

Annual Recurring

Inerting Truck Fuel $11,000 Assume 5,000 miles at 10 mpg and $1.10 per

gallon

Inerting Truck Maint ??? No data at this time

Inerting Truck

Operator Training

??? No data at this time

Inerting Truck

Inspection

$10,000 20 trucks at $500 per inspection

O2 Detector

Calibration

$2,640 Assumes 22 sensors per airport and recalibration

twice per year at mechanic’s rate of $60/hour

O2 Detector Training ??? No data at this time

9.2.3. Simple Hybrid System – Body (Center Tank) Only

The following costs are the estimate for a very simple system to inert the body tank only.

The assumed system is a hybrid system with a distribution system in the aircraft and the

inert gas supply on the ground. The distribution system consists of a quick disconnect

port for hookup to the inert gas supply, a regulator to avoid damage to the tank structure,

a check valve to keep fuel from flowing out of the tank to the nitrogen supply,

distribution pipes in the tank, and 2 vent check valves to hold the inert gas in the tank.

Equipment must be installed on the aircraft and at the airport. The airport equipment

consists of trucks carrying nitrogen in liquid or gaseous form and an oxygen detector.

Although nitrogen could be provided to each aircraft by underground pipes it’s virtually

impossible to estimate the cost impact of installing the piping at every airport. However,

it is possible to estimate the number of trucks that would be required; this task group has

assumed there would be one nitrogen truck for each refueling truck at a typical airport.

This follows since the inerting would occur during or immediately after the aircraft was

refueled. For a “typical” airport, 20 fuel trucks were assumed which is probably much

lower than the actual value. Large airports such as LAX, JFK and ORD would have

many more while smaller airports may have fewer.

The oxygen detector is needed to ensure that the fuel tanks’ oxygen content is safe. This

would be determined by having the inerting truck operator measure the oxygen level

coming out of the vent system while adding nitrogen to the tank. The operator would

have to be properly trained to use the detector and the detector would require

recalibration periodically.
28 June, 1998

TG3 46

The Task Group was not able to define all of the cost impacts due to the limited time

frame for the report, so they are left blank. The system was assumed to be installed only

on aircraft with heated body tanks. The Task Group was not able to determine if the

Regional Turbofan and Turboprop had heated body tanks for this analysis. Therefore, the

cost estimate for these aircraft is unknown. Also, the Task Group was not able to define

the system weight due to limited time so the recurring cost estimate accounts only for the

nitrogen used for inerting.

Table 12

Production Aircraft with Heated Body Tanks, Hybrid Inerting System, NonRecurring Cost

Fleet Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Design $2.3M $2.2M $4.3M Unknown Unknown $0

Installation $99.9M $85.3M $483.5M Unknown Unknown $0

Operational Unknown Unknown $0

Maintenance Unknown Unknown $0

Infrastructure Unknown Unknown $0

Range Lost Unknown Unknown $0

Total Cost $102M $87M $488M Unknown Unknown $0

# of Aircraft 1280 1092 6192 Unknown Unknown 0

Cost per

Aircraft

$150,000 $144,000 $145,000 Unknown Unknown $0

Table 13

Production Aircraft with Heated Body Tanks, Hybrid Inerting System, Annual

Recurring Cost

No Weight Penalty Assumed

Fleet Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Liquid

Nitrogen

$92,067 $49,216 $866,770 Unknown Unknown $0

Cost per

Aircraft

$71 $45 $140 Unknown Unknown $0

OR

Gaseous

Nitrogen

$36.2M $19.3M $35.1M Unknown Unknown $0

Cost per

Aircraft

$28,266 $17,711 $5,676 Unknown Unknown $0
28 June, 1998

TG3 47

Table 14

Airport Costs for Body Tank Hybrid Inerting System

Non-recurring

Nitrogen Trucks $3.3M Assumes 20 per airport

O2 Detectors $16,500 Assumes 22 per airport

Annual Recurring

Inerting Truck Fuel $11,000 Assume 5,000 miles at 10 mpg and $1.10 per

gallon

Inerting Truck Maint ??? No data at this time

Inerting Truck Operator

Training

??? No data at this time

Inerting Truck

Inspection

$10,000 20 trucks at $500 per inspection

O2 Detector Calibration $2,640 Assumes 22 sensors per airport and recalibration

twice per year at mechanic’s rate of $60/hour

O2 Detector Training ??? No data at this time

9.3. New Aircraft

9.3.1. Air Separation Technology – All Tanks

The following module costs are a composite of the costs estimated by various suppliers of

air separation modules, assuming that all fuel tanks are inerted. The other costs are

scaled from estimates made by Boeing for the industry response (July 1997) to the FAA

Request for Comment. This system includes the air separator modules, precoolers,

water/dust separator, shutoff valves, flow control valves, check valves, distribution pipes,

pressure regulators, control orifices, pressure sensors, and climb/dive check valves.

Table 15

Future Aircraft Air Separator Technology Non-recurring Costs

 Fleet Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Modules $606,000 $304,000 $113,000 $95,000 $77,000 $125,000

Design $34M $32.7M $31.9M $31.8M $31.7M $31.9M

Installation $3.9B $3.3B $18.9B $2M $1.5M $1.2M

Operational

Maintenance

Infrastructure

Range Lost

Total Cost $3.94B $3.36B $18.9B Unknown Unknown 0

# of Aircraft 1280 1092 6192 Unknown Unknown 0

Cost per

Aircraft

$8.3M $4.7M $3.4M Unknown Unknown 0
28 June, 1998

TG3 48

There is also a penalty to the aircraft due to the added weight of the system. In most

cases, the added weight merely results in extra fuel consumed to travel the same distance.

However, if the aircraft is at its maximum weight limit then some passengers cannot be

carried in order to put in the extra fuel. This results in an additional penalty for lost

revenue and appears in the row labeled “Long Mission” where the aircraft is the most full

of fuel.

Table 16

Future Aircraft Air Separator Technology Recurring Costs

Annual

Fleet Cost

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

$652.4M $190.7M $262.7M Unknown Unknown Unknown

9.3.2. Air Separation Technology – Center Tank Only

The following module costs are a composite of the costs estimated by various suppliers of

air separation modules. The other costs are scaled from estimates made by Boeing for the

industry response (July 1997) to the FAA Request for Comment. This system includes

the air separator modules, precoolers, water/dust separator, shutoff valves, flow control

valves, check valves, distribution pipes, pressure regulators, control orifices, pressure

sensors, and climb/dive check valves.

Table 17

Future Aircraft Air Separator Technology Non-recurring Costs

 Fleet Cost

(US Dollars)

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

Modules $606,000 $304,000 $113,000 $95,000 $77,000 $125,000

Design $34M $32.7M $31.9M $31.8M $31.7M $31.9M

Installation $3.9B $3.3B $18.9B $2M $1.5M $1.2M

Operational

Maintenance

Infrastructure

Range Lost

Total Cost $3.94B $3.36B $18.9B Unknown Unknown 0

# of Aircraft 1280 1092 6192 Unknown Unknown 0

Cost per

Aircraft

$8.3M $4.7M $3.4M Unknown Unknown 0

There is also a penalty to the aircraft due to the added weight of the system. In most

cases, the added weight merely results in extra fuel consumed to travel the same distance.

However, if the aircraft is at its maximum weight limit then some passengers cannot be

carried in order to put in the extra fuel. This results in an additional penalty for lost
28 June, 1998

TG3 49

revenue and appears in the row labeled “Long Mission” where the aircraft is the most

full.

Table 18

Future Aircraft Air Separator Technology Recurring Costs

Due to Added System Weight

Annual

Fleet Cost

Large

Transport

Medium

Transport

Small

Transport

Regional

Turbofan

Regional

Turboprop

Business

Jet

$333.6M $108.7M $191.7M Unknown Unknown Unknown
28 June, 1998

TG3 50

10. Conclusions

At this time, nitrogen appears to be the best inerting agent and there are several means of

providing it to the aircraft. Ground-based ullage washing in combination with the drop in

temperature within the tank reduces exposure to a flammable, non-inerted tank to

approximately 1%. This is the most cost effective solution studied, with the cost over a

10-year period estimated at approximately $3-4 billion.

Present day aircraft do not have enough bleed air, in most cases, to supply an OBIGGS

type system. However, OBIGGS systems can be designed into future aircraft without

adverse effects for the engine.

If a full time inerting system is required for present day aircraft or retrofit aircraft then

liquid or gaseous nitrogen storage could be placed aboard the aircraft. These systems

tend to be a little heavier than OBIGGS and require additional airport infrastructure to

support them. The overall cost for a 10-year period is similar to OBIGGS.

The following table provides a summary of the cost and benefit of each system.

Technology Effectiveness Cost over 10 Years (US Dollars)

On-board Liquid Nitrogen for All

Tanks

100% $35.7B

On-board Gaseous Nitrogen for All

Tanks

100% $33.9B

Air Separator Modules for All

Tanks

100% $37.3B

Air Separator Modules for the

Center Tank

100% $32.6B

Ground-based Ullage Washing with

natural Fuel Cooling for Center

Tank

99% $4B with gaseous nitrogen

$3B with liquid nitrogen
Foam

Task Group 4

Aviation Rulemaking

Advisory Committee

ARAC

JAA FAA

THE PUBLIC
17 July 1998

TG 4: FOAM 1 07/16/9812:19 PM

Abstract

This report is the findings of the Fuel Tank Foam and Expanded Metal

Products Task Group, which was formed as a portion of the Fuel Tank

Harmonization Working Group activity established in January 1998. The FAA

initiated this activity by the issuance of a Harmonization Terms of Reference

entitled “Prevention of Fuel Tank Explosions” on 16 Dec 1997. The Working

Group’s stated task was to study means to eliminate or reduce fuel tank

flammability and to propose regulatory changes to the FAA Aircraft

Rulemaking Advisory Committee.

The Fuel Tank Foam and Expanded Metal Products Task Group’s assignment

was to provide a feasibility analysis of fuel tank foam and expanded metal

products installation systems. The analysis was to focus on the use of foam

and expanded metal products in prevention of fuel tank explosion for transport

airplane operations. A cost/benefit analysis for fuel tank foam installation

systems was to be included for the fleet of aircraft requiring retrofit, for current

production aircraft, and for new type design aircraft.

The findings for this Task Group indicates that foam or expanded metal

products can be used effectively in the prevention of structural failure of fuel

tanks as a result of an explosion. However, when installed foam or expanded

metal products will reduce aircraft payload and available fuel volume. These

reductions are the two most important factors that would result in severe

economic impact for airlines
21 July 1988

TG 4: FOAM 2 07/16/9812:19 PM

Summary

This report provides information on two types of materials available for

installation inside aircraft fuel tanks which will reduce the risks of hull losses

of aircraft in case of explosions:

1. Reticulated polyether foam

2. Expanded metal products.

Both have more than one application, and both will require FAA certification.

Some will require extensive qualification tests to aircraft standards. When

installed inside fuel tank both materials create its own disadvantages such as

weight increase, fuel volume loss, increase pack bay temperature causing

degradation of aircraft structural integrity, FOD and maintenance difficulties.

The installation of either system has no real effect on normal fuel system

operation and the each system is virtually maintenance free. However, the

presence of the materials in the fuel tank greatly impacts the

removal/replacement of in-tank components. Time to remove, store, and

reinstall the materials must be added to the normal time necessary for fuel

system components maintenance. This effect on operational aircraft has been

accounted for in the cost estimate.

Foam also requires special handling and wrapping if it is to be out of the tank

for an appreciable length of time. Further, foam which is no longer usable, is

difficult to dispose of without environmental damage.

Costs associated with using one alternative of each product have been

estimated for generic center tanks, which have adjacent heat sources. These

estimates account for total cost, i.e., designs, installations, and operations. The

estimates are based on data collected from vendors, from the United States

Department of Defense, from aircraft manufacturers, and from airlines.
July 17 1998

TG 4: FOAM 3 07/16/9812:19 PM

These cost estimates, for center wing tank with adjacent heat source, are

summarized in the following two tables:

In service aircraft

Aircraft Size Foam

Nonrecurring

Foam

Annual

Exp Metal

Nonrecurring

Exp Metal

Annual

Large $390,740 $1,584,121 $848,273 $1,329,017

Medium $187,427 $653,497 $366,057 $538,951

Small $64,161 $120,448 $112,605 $88,992

Production Aircraft

Aircraft Size Foam

Nonrecurring

Foam

Annual

Exp Metal

Nonrecurring

Exp Metal

Annual

Large $353,884 $1,584,121 $811,416 $1,329,017

Medium $166,334 $653,497 $344,964 $538,951

Small $54,636 $120,448 $103,081 $88,992

It is estimated that it would cost the industry , in a 10 year period, over 22

billion dollar to use Expanded Metal Products and over 25 billion dollar to

use Foam on inservice aircraft.
21 July 1988

TG 4: FOAM 4 07/16/9812:19 PM

Acknowledgments

The members of the Airworthiness Rulemaking Advisory Committee, Fuel

Tank Harmonization Working Group, Task Group 4 wishes to thank the

following people for their cooperation, advice, and information:

• Patrick Wagoner, Lockheed Martin, Fairborn Ohio

• Beatrice Rodriguez, Wright Patterson AFB

• Ralph Lauzze, Wright Patterson AFB

• Allen Fletcher, Wright Patterson AFB

• Dexter Kalt, Wright Patterson AFB

• Col. Ken Peters, Robins AFB

• Pearl Alexander Robins AFB,

• Donald Miller, Warner Robins AFB

• Harry Mattox, Lockheed Martin Support Services Co., Jacksonville, Fl.

• Roger Boone, NAS Jacksonville, and various members of NAS

Jacksonville's maintenance squadrons.
July 17 1998

TG 4: FOAM 5 07/16/9812:19 PM

The members of Task Group 4 also wish to thank the following vendors for

providing data on reticulated foam and expanded metal products:

Foam Products:

Crest Foam

100 Carol Place 

Moonachie, NJ 07074

Engineered Fabrics Corporation

669 Goodyear St.

Rockmart, GA 30153

Foamex

1500 East Second Street

Eddystone, PA 19022

Middle Georgia Easter Seal Society, Inc.

Kellam Road, P.O. Box 847

Dublin, GA. 31040
21 July 1988

TG 4: FOAM 6 07/16/9812:19 PM

Expanded Metal Products:

AT&E Engineering

425 East Main St. P.O. Box 8

East Moriches, NY 11940

Deto-Stop, Inc.

1665 Townhurst, Suite 100

Houston, TX 77043

Explosafe North America

16 ESNA Park Dr. Suite 101

Markham. Ontario Canada, L3R5X1

Firexx Corporation

Suite 1000, 1611 North Kent St.

Arlington, VA 22209

International Door

8001 Ronda Dr.

Canton, MI 48187

SafetyTech

Suite 300

1749 Golf Road

Mount Prospect, IL 60056
July 17 1998

TG 4: FOAM 7 07/16/9812:19 PM

References

1. Terms Of Reference, ARAC, FTHWG, January 1998

2. Advisory Group for Aerospace Research & Development, Report No. 771,

Fuel Tank Technology

3. MIL-F-87260 (7 February 1992) Foam Material, Explosion Suppression,

Inherently Electrically Conductive, For Aircraft Fuel Tank and Dry Bay Areas.

4. MIL-B-83054B, 17 May 1978, Baffle and Inerting Material, Aircraft Fuel

Tank

5. MIL-B-87162 Baffle Materials, Explosion Suppression, Expanded

Aluminum Mesh, for Aircraft Fuel Tank.

6. Society of Automotive Engineers Aerospace Information Report, AIR4170,

12 February, 1991, Reticulated Polyurethane Foam Explosion Suppression

Material for Fuel Systems and Dry Bays.

7. AFWAL-TL-80-2043 Evaluation of Explosafe Explosion Suppression

System for Aircraft Fuel Tank Protection.
21 July 1988

TG 4: FOAM 8 07/16/9812:19 PM

Table of Contents

Abstract 1

Summary 2

Acknowledgments 4

References 7

Table Of Contents 8

1.0 Background of Explosion Suppression Materials 11

1.1. Foam Products 11

1.2 Expanded Metal Products 14

1.3 Some Weight Increase and Fuel Volume Loss Comparison 14

2.0 Design Alternatives 17

2.1 Introduction 17

2.2 Fully Packed Coarse Pore Reticulated Foam 21

2.3 Grossly Voided Fine Pore Reticulated Foam 23

2.4 Expanded Aluminum Mesh, Block Form 24

2.5 Expanded Aluminum Mesh, Ellipsoid Form 26

2.6 Selective Tank Explosion Suppression Material Installation 27

2.7 Selective Installation of Foam or Aluminum Foil Around

Ignition Sources 28

3.0 FAA Certification Requirements 31

3.1 General 31

3.2 Similarity and Previous Test or Flight Experience 31

3.3 Additional Analysis and Testing 31
July 17 1998

TG 4: FOAM 9 07/16/9812:19 PM

4.0 Safety 33

4.1 Effectiveness in Preventing Overpressure Hazard 33

4.2 Effects of Range Reduction and Additional Flights 33

4.3 Effects of Weight Increase 34

4.4 Personnel Hazards 35

5.0 Aircraft Hazards or Effects 36

5.1 General 36

5.2 Electrostatic Charge Hazards 36

5.3 Air-condition Pack Bay Temperature & Structure Degradation 36

5.4 Fuel Contamination and Foam Deterioration 37

5.5 Effects on Other Fuel System Components 40

5.6 Corrosion, Water Retention, and Biological Contamination 41

5.7 Other Equipment Hazards or Effects 42

7.0 Overall Safety Assessment 44

8.0 Cost Analysis 46

8.1 Assumptions 52
21 July 1988

TG 4: FOAM 10 07/16/9812:19 PM

1.0 Background of Explosion Suppressive Materials

The explosion suppressive materials acts as suppressants when installed in fuel

tanks because they:

1. Act as heat sinks, thus reducing the temperatures at spark points,

2. Break up compression waves that precede flame fronts in an explosion,

and

3. Enrich the mixture of vapors in the ullage of fuel tanks, especially in tanks

with JP-4 or similar fuels are used.

In this report the two types of Explosion Suppressive Materials under

examined are Foam and Expanded Metal Products.

Both types of materials provide passive systems. No moving parts are

required, and no cockpit instrumentation equipment is required. When the

systems are properly designed and installed, ullage protection is ensured during

all ground and flight conditions.

However, there are disadvantages to utilizing these materials:

• Both reduce gross take off weight and/or range of aircraft due to the system

weight increase and reduction in usable fuel quantities.

• Both increase aircraft maintenance down time and labor cost due to the

additional time required to drain the tanks, and to remove and replace the

products for in tank maintenance.

• Foam when installed inside the center wing tank may act as an insulator,

which could hinder the thermal dissipation of heat energy produced by the air-
July 17 1998

TG 4: FOAM 11 07/16/9812:19 PM

condition packs mounted underneath the tank. This could elevate the aircondition packs bay and degrade the surrounding structure integrity.

• Storage of removed materials will require special facilities.

• Foam does have a limited life (approximately 15 to 20 years). Therefore,

disposal of fuel soaked foam will be an environmental issue.

1.1 Foam Products

Military aircraft are highly vulnerable to fires and explosions resulting from

combat threats such as gunfire, especially high explosive incendiary (HEI)

rounds. During the late 1960s, the United States Air Force began using

reticulated polyester polyurethane foam to suppress fires and explosions inside

fuel tanks. Figure 1 and Figure 2 are photographs of a typical C-130 tank with

foam installed. Since that time, several materials have been tried, the latest

being per MIL-F-87260, Reference 4. A typical C-130 requires 1540 pieces of

foam. A P-3 requires 1388 pieces. Figure 3 is a photograph of the foam for a

P-3 fuel tank.
21 July 1988

TG 4: FOAM 12 07/16/9812:19 PM

Figure 1 - C-130 Fuel Tank with Foam Installed

Figure 2 - C-130 Fuel Tank with Foam Installation Ongoing

View Looking Inbd
July 17 1998

TG 4: FOAM 13 07/16/9812:19 PM

Soon after the development and incorporation of fuel tank foams, the Air Force

discovered that the materials used for the foam were susceptible to hydrolytic

degradation. Better materials were developed; producing what is commonly

called blue foam.

The blue foam improved hydrolytic stability, but the blue foam had electrical

resistance properties much higher than the original foam materials, causing a

capacitance effect resulting in static charge potentials greater than 10,000

volts. Soon after incorporation of the blue foam kits, the USAF experienced

fuel tank fires in the A-10 and the C-130 aircraft. Thousands of fuel tank fire

remnants were discovered in the C-130 fleet, but no loss of an aircraft was ever

attributed to fuel tank fires. This static electrical discharge problem led to the

development of the conductive foams, which are now being produced and

installed in quite a number of USAF and USN aircraft.

Figure 3 - A P-3 Foam Kit Being Prepared for Shipment
21 July 1988

TG 4: FOAM 14 07/16/9812:19 PM

1.2 Expanded Metal Products

The expanded metal products have been used in fuel tanks and storage

containers, and many tests have been conducted to prove that the products,

mostly aluminum alloys, will protect fuel tanks from explosions as a result of

internal ignition. However, as of the time this document was written, the

United States Department of Defense has not approved any of the expanded

metal products for use on any particular aircraft weapon system. MIL-B87162, Ref. 5, was approved for expanded metal blocks, but the product has

been incorporated on a limited basis. Likewise, the FAA has not yet issued a

type certificate for any aircraft that uses the expanded metal products for

explosion protection. However, this does not mean they are not effective or

will never be used. For example, several of the expanded metal products can

be purchased in the form of ellipsoidal or cylindrical shaped objects such as

those shown in Figure 4. Aircraft fuel tanks will require design changes to

incorporate constraining baffles or cages to ensure the particles remain in

position, especially in an aircraft without access to the tank interiors from the

top of the wings. This and other concerns require more design and

development. Figure 5 is a photograph of the expanded aluminum blocks that

conform to MIL-B-87162.

1.3 Some Weight Increase and Fuel Volume Loss Comparison

Beside additional maintenance burdens and environment issue the most severe

penalties as a result of foam installation, are the fuel volume loss and the

weight increase. These two factors directly effect the bottom line of airlines

operation. The following tables summarize the weight and fuel volume

penalty for the 3 classes of aircraft between the two types of material.
July 17 1998

TG 4: FOAM 15 07/16/9812:19 PM

Foam

Volume Loss (Gallon) Weight Increase (Lb)

Large 1250 8532

Medium 500 3413

Small 150 1024

Expanded Metal Products

Volume Loss (Gallon) Weight Increase (Lb)

Large 600 9362

Medium 240 3745

Small 72 1123
21 July 1988

TG 4: FOAM 16 07/16/9812:19 PM

Figure 4 - Ellipsoidal and Cylindrical Shaped Expanded Metal Products

Figure 5 - Expanded Metal Blocks
July 17 1998

TG 4: FOAM 17 07/16/9812:19 PM

2.0 Design Alternatives

2.1 Introduction

There are several design alternatives for design and installation of explosion

suppression material, both with respect to type of material and installation

design. This section will outline the various alternatives, explain the benefits,

drawbacks, service experience and anticipated certification requirements of

each, and select a baseline alternative based on best proven suitability for

transport aircraft. Other alternatives may be suitable for specific applications,

as determined by the aircraft manufacturer or modifier and certifying authority;

however, additional testing may be required to establish suitability. The

alternatives to be considered are:

• Fully packed coarse pore reticulated foam

• Grossly voided fine pore reticulated foam

• Expanded Aluminum Mesh, Block Form

• Expanded Aluminum Mesh, Ellipsoid Form

• Selective Tank Installation

• Selective Installation Around Ignition Sources

Figure 6 presents a graph of explosion overpressure versus void volume for

various alternative materials. Table 1 presents a comparison of other

properties of various alternative materials, and Table 2 summarizes major

advantages and disadvantages of alternative materials and designs. These will

be referred to within the sections discussing each alternative.
21 July 1988

TG 4: FOAM 18 07/16/9812:19 PM

Figure 6

Explosion Overpressure versus Void Volume and Operating Pressure

0

5

10

15

20

25

30

35

40

45

50

0 10 20 30 40 50 60 70

Void Volume-- %

Explosion Overpressure-- PSID

Coarse Pore Foam, O.P.=.5 Coarse Pore Foam, O.P.=3.0 Fine Pore Foam, O.P=.5

Fine Pore Foam, O.P.=3.0 Mesh, T2, Cl B, O.P.=3.0 Mesh, T3 Cl A, O.P.=3.0

Mesh, T3 Cl B, O.P.=3.0
 21 July 1998

TG 4 : FOAM 19

Comparison Item Coarse Pore

Foam

Fine Pore Foam Aluminum Mesh, Block Type Aluminum Mesh,

Ellipsoid Type

Specification MIL-F-87260 MIL-F-87260 MIL-B-87162 None

Normal

Installation

Fully Packed Grossly Voided Fully Packed Fully Packed

Class, Grade, Type Class 1 or 2, Grade

IC

Class 1 or 2, Grade

IIC

Type I Type II, Class A Type II, Class B Type III, Class A Type III, Class B N/A

Material Polyether Polyether 3000 Series Aluminum Foil Aluminum Foil

Max. Density,

lb/ft3

1.50 1.50 1.7 2.0 2.3 2.7 3.2 3.0 (est)

Max. Fuel

Displacement-%

2.50 2.50 1.2 1.2 1.4 1.6 1.9 1.0—2.0 (est)

Max. Fuel

Retention-%

2.50 5.00 1.0 .8 1.0 .8 .9 1.0 (est)

Conductive Yes Yes Yes Yes Yes Yes Yes Yes

Nominal Pore/Cell

Count-No./In.

15 29 3.5 3.1 3.5 3.0 3.4 3.0 (est)

Foil Thickness

Mils

N/A N/A 1.5 2.0 2.0 3.0 3.0 Unknown

Entrained Solid

Contamination

mg/ ft3

11.0 Max 11.0 Max 14.0 Max 14.0 Max 14.0 Max 14.0 Max 14.0 Max Unknown

Estimated Cost,

Uninstalled, $/cu.

Ft.

12.00-24.00 12.00-24.00 33.00-66.00 33.00-66.00 33.00-66.00 33.00-66.00 33.00-66.00 28.0-75.00

Table 1

Explosion Suppression Material Properties

Note

Variation in uninstalled cost is due to vendor estimate variation and uncertainties as to production quantity and number and configuration of individual blocks.
 21 July 1998

TG 4 : FOAM 20

Type Of Installation Advantages Disadvantages

Coarse Pore Foam, Fully Packed Well proven including transport type aircraft

Low overpressure

Complete protection

Weight and fuel volume penalties

Contamination potential

Deterioration potential

Maintenance time penalty

Fine Pore Foam, Grossly Voided Lower weight and fuel volume penalties

Complete protection

Higher overpressure

Requirement to prevent propagation between bays

Foam retention requirement

Contamination potential

Deterioration potential

Maintenance time penalty

Aluminum Mesh, Block Type, Fully Packed Lower fuel volume penalty

Less deterioration potential

Complete protection

Not proven in aircraft applications

Higher weight penalty

More difficult installation and removal

Contamination potential

Maintenance time penalty

Aluminum Mesh, Ellipsoid Type, Fully Packed Lower fuel volume penalty

Less deterioration potential

Complete protection

Not proven in aircraft applications

No aircraft application specification or testing

Higher weight penalty

More difficult installation and removal

Contamination potential

Maintenance time penalty

Selective Tank Installation Lower weight, fuel volume, cost, maintenance time penalties Same as selected material

Requirement to prevent propagation to unprotected tanks.

Selective Installation Around Potential Ignition Sources Much lower weight, fuel volume, cost, maintenance time

penalties

Same as selected material

Requirement to prevent propagation to unprotected portions of

tanks.

Difficult to apply to potential ignition sources in other than

discrete locations

TABLE 2

Design Alternatives Comparison
21 July 1998

TG 4: FOAM 21 07/12/987:09 PM

2.2 Fully Packed Coarse Pore Reticulated Foam

This alternative consists of installation of reticulated foam with a small amount

of voiding so that the foam occupies the majority of the affected tank volume.

Current and future design utilizes conductive polyether foam per MIL-F87260, Class 1, Grade IC or Class 2, Grade IC. These foam grades incorporate

improvements to prevent deterioration and electrostatic discharge problems

experienced with earlier types of foam, as previously discussed. The difference

between Classes is that Class 1 maintains electrical conductivity down to 10° F

and Class 2 maintains electrical conductivity down to -20° F. There is

currently one qualified manufacturer of the preferred Class 2 foam, however,

another manufacturer, qualified for Class 1 foam, is currently undergoing

qualification.

The absence of electrical conductivity at these low temperatures is not

considered to constitute an ignition source for normally used kerosene type

fuels and extensive military experience has shown that ignition of wide cut

fuels is not a safety hazard since thousands of ignitions have occurred with no

aircraft losses, and no significant aircraft damage except in a few instances of

improperly or incompletely installed foam. In many instances, ignition was

not detected until the foam was removed and found singed during later

maintenance. It may be advisable to prohibit over-wing refueling at low

temperatures when using wide cut fuels; however, this situation very rarely

occurs and is not considered a significant penalty for transport category aircraft

operations.

This alternative has been widely used in all of military transport type aircraft

foam installations (C-130 and P-3), many other military aircraft installations,

and in certain business jet fuselage tank installations.

The foam is installed in the form of blocks cut into engineering defined shapes.

Voids of dimensions recommended in SAE AIR 4170 are located to provide

clearance around components such as pumps, valves, fuel quantity probes,
21 July 1998

TG 4: FOAM 22 07/12/987:09 PM

flapper valves, plumbing inlets and outlets, etc. Additional voiding up to the

limit suitable for the particular application is located in individual blocks and

typically consists of 4.0” diameter horizontal holes located so that holes in

adjacent blocks do not line up. It is typical for total void volume to not exceed

20%. As can be seen from Figure 6, a 20% void installation with a tank ullage

operating pressure of 0.5 psig, which is typical of transport category aircraft,

produces a combustion overpressure of 6.0 psig. This is likely to be within the

limit pressure capability of most transport aircraft fuel tanks. If necessary, the

combustion overpressure could be reduced to 2.5 psig by reducing the void

volume to 10%.

Foam blocks are designed to near nominal shape and size, with the specified

voids, and become self-supporting by 10-20% swelling when wet with fuel.

Retainers or guards are recommended practice only for components with

exposed floats, but may also be considered for other components with exposed

moving parts, such as flapper valves, and for fuel quantity probes. The number

of blocks required is a function of bay size, access opening size, and internal

plumbing and structure complexity. A typical practice is to not install foam in

sump or pump bay areas where the installation may be difficult and which are

always full of fuel down to the fuel level where fuel exhaustion is imminent.

Application of this practice to commercial transport aircraft would vary with

different fuel system designs. C-130 and P-3 aircraft have tanks, which appear

to be of greater complexity than comparable size narrow body airliners. It is

beyond the scope of this report to determine design factors for specific aircraft;

however, it is estimated that the number of blocks is unlikely to be less than

250 or more than 6,000 over the complete range of transport category aircraft.

Based on the extensive experience and data which show suitability for

transport category aircraft, the fully packed reticulated foam system is

considered to be the baseline system for purposes of this report, with cost data

presented in Section 8.
21 July 1998

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2.3 Grossly Voided Fine Pore Reticulated Foam

This alternative consists of designs that have a much higher proportion of the

fuel tank volume, which is devoid of foam than the baseline fully packed

alternative. The intent of this design is to minimize the weight and fuel volume

penalties. Current and future design utilizes conductive polyether foam per

MIL-F-87260, Class 1 Grade IIC or Class 2, Grade IIC. A typical design

would involve tanks divided into bays by spars, bulkheads, and ribs, where the

foam is installed at the bay boundaries to prevent explosion propagation from

one bay to another. It is necessary to incorporate means to retain the foam in

place. Adhesives have been successfully used. Void volumes have been as high

as 70%.

Table 1 shows that the density and fuel displacement of fine pore foam is the

same as coarse pore foam, while fuel retention is twice as much. It is,

therefore, necessary for the void volume to be at least approximately 40% for

this alternative to be of benefit. Figure 6 shows a combustion overpressure of

10.7 psig for a void volume of 40% with a tank operating pressure of 0.5 psig.

The combustion overpressure rises to 28.2 psig at a 60% void volume where

significant benefits are available. The exact amount of overpressure and its

extent depends on the expansion characteristics of combustion products and is

an application specific function of number of bays, bay size and arrangement,

and intercommunication among bays. For this reason, military applications of

grossly voided designs have been limited to tanks capable of significant

overpressure, such as fighter aircraft wing tanks. The F-15 wing tanks are one

example. This design cannot be considered generally suitable for transport

category aircraft for this reason, although it may be suitable for some tanks or

portions of tanks on some aircraft, if substantiated by tests.

Certification considerations for this alternative are similar to those for fully

packed design, discussed in Section 3, with the additional requirements that

explosion suppression testing is considered mandatory to determine the amount
21 July 1998

TG 4: FOAM 24 07/12/987:09 PM

of overpressure, the ability of the design to prevent propagation between bays,

and the ability of the tank structure to withstand the resulting localized

overpressure.

A grossly voided reticulated foam design has not been selected as the baseline

for transport category aircraft application due to the above considerations, and,

therefore, no cost data is presented in Section 8.

2.4 Expanded Aluminum Mesh, Block Form

This alternative consists of a nominally fully packed installation of shaped

blocks of expanded aluminum foil mesh. Material is defined by MIL-B-87162,

and as shown in Table 1, several different combinations of foil thickness and

density are defined. Currently available material has not been qualified to this

specification. This generic type of material has been subjected to explosion

suppression and material qualification testing, and installation evaluation in

several small tanks, as documented in Report AFWAL-TR-80-2043, however

there are no known military aircraft applications, including test applications.

There may have been a small number of civil and military aircraft applications,

either on small experimental aircraft or production aircraft, not in the transport

category, approved on an individual aircraft, non-hazard basis.

As shown on Figure 6, overpressure potential is higher than foam under

equivalent test conditions. For this reason, explosion suppression testing may

be required for at least the first aircraft application.

As shown in Table 1, the aluminum mesh material has a higher weight but

lower fuel displacement and retention than foam, with the amount varying

depending on the specific type.

Due to the lack of flexibility and compressibility compared to foam, this

installation is likely to require a larger number of individual blocks and to be
21 July 1998

TG 4: FOAM 25 07/12/987:09 PM

more difficult to handle. Methods to prevent the blocks from shifting and to

provide required clearance for components would require development. It is

likely that more guards or retainers would be required than for foam.

One item of concern is that effect of long term installation on the integrity of

both the mesh material and the protective coatings on the internal tank

structure. The mesh material integrity question relates to vibration, sloshing

and other mechanical action, since it is less susceptible to material

deterioration than foam. MIL-B-87162 addresses this question by requiring

slosh tests on both a metal tanks, with the mesh material in contact with

representative coating and sealant patches, and on a bladder tank. Report

AFWAL-TR-80-2043 addresses these issues in an apparent satisfactory

manner except for unresolved questions regarding the tendency of the material

to settle and create additional unintended void volume.

Certification for transport category aircraft application would involve

considerations similar to those discussed in Section 3 plus expansion to

adequately quantify the explosion protection characteristics in relation to the

aircraft fuel tank structural capability, and to demonstrate that installation

compatibility and continued airworthiness requirements can be satisfied in a

consistent manner.

Expanded aluminum mesh in block form in a fully packed installation is

considered to be a potentially feasible alternative for transport category aircraft

application. Although additional development is required, it is considered

sufficiently feasible that cost data is presented in Section 8 for the selective

tank installation option (heated center wing tanks) discussed further in Section

2.6.
21 July 1998

TG 4: FOAM 26 07/12/987:09 PM

2.5 Expanded Aluminum Mesh, Ellipsoid Form

This alternative consists of expanded aluminum mesh material similar to that

discussed above, except that the material is formed into small ellipsoid or

cylindrical shapes, with a maximum dimension of approximately 1-2”.

Military aircraft experience is limited to a recent application in an U.S.

manufactured helicopter in European service. Little detailed information is

available.

Testing has been done to demonstrate explosion suppression capability in

applications such as ground vehicle fuel tanks, however the test conditions are

not similar enough to provide direct comparison with aircraft application

requirements. Weight, fuel displacement, and fuel retention characteristics are

estimated to be similar to block form expanded aluminum mesh discussed in

Section 2.4.

Installation in tanks with access openings on the top could be done by gravity

methods, however, for the more common case of tanks with access openings

on the bottom, a method such as blowing in the ellipsoids with forced air

would require development. Installation concerns would include requirements

for assuring complete filling, especially near the top of the tank, and

installation of access covers without escape of the material. Removal of the

material for maintenance or inspection would be anticipated to be a problem

with either top or bottom openings. Extensive guards to provide component

clearance and prevent material entrance into plumbing passages are anticipated

to be necessary. Concerns regarding settling of the material are similar to

those for block type aluminum mesh material.

Certification for transport category aircraft application would involve

considerations similar to those discussed in Section 3 plus expansion to

adequately quantify the explosion protection characteristics in relation to the

aircraft fuel tank structural capability, and to demonstrate that installation
21 July 1998

TG 4: FOAM 27 07/12/987:09 PM

compatibility and continued airworthiness requirements can be satisfied in a

consistent manner.

It is unclear whether expanded aluminum mesh in ellipsoid form in a fully

packed installation can be considered to be a potentially feasible alternative for

transport category aircraft application without further testing and development.

It is not selected as the baseline system due to the disadvantages discussed and

the lack of aircraft service experience. Cost data is, therefore not presented in

Section 8. It is noted, however, that costs would be very similar to the data

presented for block type expanded aluminum mesh, subject to satisfactory

installation development.

2.6 Selective Tank Explosion Suppression Material Installation

This alternative involves installation of one the alternatives discussed above in

only selected tanks instead of all tanks of a particular aircraft model. The

considerations, advantages, disadvantages, and certification considerations for

the particular type of system would apply in a smaller scale in proportion to the

tank volume protected.

One exception that is important for selective tank installation is the possibility

of self generated ignition, which could propagate to an unprotected tank. This

would apply if the protected tank was interconnected to unprotected tanks in a

manner which could propagate an explosion. The most obvious example is

tanks interconnected to a common vent surge box, however interconnection

through transfer, refuel/defuel, or other systems may require consideration.

The only identified explosion caused by reticulated foam is static electrical

charge accumulation and ignition of wide cut fuel at low temperatures where

the foam becomes much less conductive. Prohibition of operation with wide

cut fuels is considered an acceptable means to address this concern. Another
21 July 1998

TG 4: FOAM 28 07/12/987:09 PM

means would be to eliminate any interconnection by which an explosion could

propagate. It is uncertain whether other means traditionally used to minimize

static charge ignition probability could be substantiated to the necessary high

confidence level and extreme improbability of occurrence.

Static electricity charge accumulation is not a consideration with expanded

aluminum mesh, however, other ignition modes, such as sparking when the

mesh is conducting lightning strike current, would require consideration. This

would be a particular concern with composite tanks, which are not widely used

in transport category aircraft.

Certification considerations for selective tank explosion suppression material

installation in transport category aircraft would involve the considerations

applicable to the method chosen, determination of which tanks require

explosion suppression, and prevention of explosion propagation to unprotected

tanks.

This alternative is considered to be a feasible alternative for transport category

aircraft, subject to the considerations discussed, and subject to the requirement

to minimize explosion hazards to a required level, as opposed to eliminating

them.

2.7 Selective Installation of Foam or Aluminum Foil Around

Ignition Sources

This alternative involves installation of explosion suppression material around

theoretical potential ignition sources in a manner, which will prevent an

ignition at that source from propagating. This involves consideration of the

flame arresting characteristics of the material. It should be noted that MIL-F87260 requires flame arrestor testing of Class IIC fine pore foam at maximum

thicknesses of three to five inches, depending on void volume and operating
21 July 1998

TG 4: FOAM 29 07/12/987:09 PM

pressure, and that such a requirement is not established for other materials.

This is not a critical concern since the flame arresting capability would also be

installation dependent and would require testing for any material.

This alternative is most applicable to discrete theoretical potential ignition

sources, such as fuel quantity probes, electrical motors and other electrical

components within the tanks. Application to more widely spread theoretical

potential ignition sources such as wires, potential points of static charge

accumulation, or ignition sources external to the tanks, is more difficult, and

sources such as these may be more appropriately addressed by other ignition

prevention means which are outside the defined scope of this report.

Explosion suppression material installation may take two possible forms,

depending on the size and configuration of the fuel systems involved:

The first, which is most applicable to smaller systems or smaller tank bays,

would consist of installation in the entire bay where the potential ignition

source is located. It would be necessary to assure propagation to adjacent bays

is prevented especially where the potential ignition source is located adjacent

to a bay boundary with openings.

The second method consists of localized explosion suppression material

installation around the ignition source. It would be necessary to suitably retain

and restrain the material, and prevent explosion propagation through any joints

in the material and at interface boundaries between the material and tank

structure or other components.

Means to prevent self induced ignition and explosion propagation in the

unprotected portions of the tank, as previously discussed in Section 2.6, are

required. Considerations are much the same as discussed in Section 2.6. It is

noted that this alternative may have less susceptibility to static charge

accumulation in reticulated foam, or lightning strike current in expanded mesh,

due to limited amount and specific configuration of the material.
21 July 1998

TG 4: FOAM 30 07/12/987:09 PM

Certification considerations for selective explosion suppression material

installation around theoretically potential ignition sources in transport category

aircraft would involve the considerations applicable to the material chosen,

determination of which ignition sources require explosion suppression, and

demonstration of no explosion propagation, either self induced or from the

ignition source.

This alternative is considered to be a feasible alternative for transport category

aircraft, subject to the considerations discussed, and subject to the requirement

to minimize explosion hazards to a required level, as opposed to eliminating

them. It is not selected as the baseline alternative, since compliance with the

FTHWG Terms of Reference is not entirely clear.
21 July 1998

TG 4: FOAM 31 07/12/987:09 PM

3.0 FAA Certification Requirements

3.1 General

This section discusses FAA certification requirements, which are

recommended for the baseline fully packed reticulated foam installation

alternative. Other alternatives may include additional certification

requirements discussed in Sections 2.2 through 2.7, including demonstration of

explosion protection effectiveness, showing absence of self induced ignition

hazards, and aircraft

3.2 Similarity and Previous Test or Flight Experience

Explosion suppression testing is not considered to be necessary based on foam

qualification testing and extensive military experience. Analysis would

determine the void fraction and overpressure from available test data, which

would then be compared to allowable tank limit pressure based on existing

certification data. Other factors discussed below, such as effects on refueling

or fuel flow and pressure delivery, may be acceptable on the basis of similarity

for additional models with similar fuel systems and foam installations, after

testing on the first model has shown expected minimal effects.

3.3 Additional Analysis and Testing

The following additional analysis and testing is recommended as part of FAA

certification:
21 July 1998

TG 4: FOAM 32 07/12/987:09 PM

Flight testing followed by ground inspection is recommended to verify

adequacy of the design to properly retain the foam blocks, and to verify

adequacy of recommended flushing procedures and contamination inspections.

Usable fuel volume and calibration of fuel quantity indicating systems will be

affected by the foam installation and will need to be substantiated during

certification. A wet fuel quantity indicating system calibration is acceptable,

but not necessarily required, unless otherwise required for the specific type of

aircraft and system. Alternative methods would include determination of the

reduction in usable fuel either by ground test, or by using the conservative

specification or qualification test values, followed by modification of the fuel

quantity indication system to incorporate the required scaling factor, and

verification of this scaling factor by bench test.

Ground tests for satisfactory refueling, including tank pressure during

maximum rate refueling, and for fuel flow and pressure delivery to the engine,

and for other operations such as transfer, would be required unless similarity

data is available from previous certifications.

Operational documentation requirements for certification include

modifications to the Approved Flight Manual, Weight and Balance Manual,

Maintenance Manual, Illustrated Parts Manual and other similar documents.
21 July 1998

TG 4: FOAM 33 07/12/987:09 PM

4.0 Safety

4.1 Effectiveness in Preventing Overpressure Hazard

There is extensive military test and operational experience, including

thousands of electrostatic self induced ignitions, that indicates that a properly

installed fully packed reticulated foam installation is 100% effective in

preventing overpressure hazards resulting from any internal or external ignition

source. Complete prevention of all hazards when tank structural integrity is

breached by mechanism external to the tank cannot be assured due to fire

hazards and structural effects of the breach of tank integrity.

4.2 Effects of Range Reduction and Additional Flights

Range would be reduced by up to 5% on flights with full or near full tanks due

to the reduced fuel tank capacity. Range would be reduced by the same amount

on flights with less than full tanks in cases where weight limitations would not

allow sufficient additional fuel to be carried to compensate for foam and

retained unusable fuel weight. Range would be reduced by 0-5% on flights

where the aircraft is near, but not at the fuel capacity or weight limit. Range

reduction due to increased weight on other flights is not a factor, since

sufficient additional fuel could be carried to compensate for the increased fuel

burn.

If it is assumed that all flights carry no more than the fuel required by the

applicable operating regulations, there would be no safety impact due to range

reduction. Validation of this assumption is beyond the scope of this report. It

is noted, however, that there could be a reduction in the capability to carry

more fuel, at the discretion of the operator or flight crew, than the amount

required.
21 July 1998

TG 4: FOAM 34 07/12/987:09 PM

It is considered reasonable and conservative to estimate a 1% increase in

departures due to the fuel penalty when limited by tank capacity or weight.

Applying the 1987 to 1996 overall worldwide hull loss rate of 1.60 per million

departures documented in the same industry response, this results in a rate of

.016 losses per million departures due to additional departures. It is noted that

these statistics involve FAR 121 type operations, however, it is considered

reasonable to conclude that they are also representative of operations involving

transport category regional airlines and business aircraft.

4.3 Effects of Weight Increase

The weight increase for a flight with full tanks is insignificant due to the foam

weight being compensated for by reduced fuel capacity due to displaced fuel.

The weight increase for flights with less than full tanks is 5% of the total fuel

capacity weight, assuming sufficient fuel is carried for equal range. If the

flight is weight limited, there is a potential safety hazard associated with

human error resulting in exceeding weight limits. If the flight is not weight

limited, the increased weight will still reduce aircraft runway and climb

performance and therefore, represents some level of hazard in the event of

human error or combination of adverse conditions, such as wind shear, where a

small difference in performance could have a decisive impact on the outcome.

These effects are not considered quantifiable and would present very low

hazards considering normal certification and operational practices. The

historical record does not support an assessment of the hazards of such a small

performance decrement due to a weight difference equal to 5% of fuel capacity

or approximately 1.5-2.5% of maximum takeoff weight.
21 July 1998

TG 4: FOAM 35 07/12/987:09 PM

4.4 Personnel Hazards

The primary personnel hazard associated with a fully packed reticulated foam

installation are those associated with maintenance personnel contact with fuel

wetted foam and fire protection issues associated with fuel wetted foam during

maintenance activities, either during tank entry or when the foam is removed

for maintenance. It is noted that fuel wetting of the foam is reduced

significantly by extended drainage and tank ventilation time periods prior to

tank entry. It is considered that these hazards can be sufficiently mitigated by

expansion of existing maintenance precautions associated with these hazards,

and that human error or failure to follow procedures is possible but no more

hazardous than existing aircraft, especially when considering the potential

reduction in fuel tank explosion hazard vulnerability during maintenance. The

time and difficulty associated with tank ventilation with foam installed tends to

mandate the use of respirators by in-tank maintenance personnel. As discussed

in Section 2.2, there is a theoretical personnel hazard associated with over

wing refueling using wide-cut fuels at extremely low temperatures, which

could be prevented by prohibiting this operation.
21 July 1998

TG 4: FOAM 36 07/12/987:09 PM

5.0 Aircraft Hazards or Effects

5.1 General

This section will address potential theoretical hazards associated with

reticulated foam. Some of these are not actual hazards, but the discussion is

included due to questions typically raised. These discussions apply to the

baseline fully packed reticulated foam installation in all tanks. Other potential

hazards associated with other design alternatives are discussed in Section 2,

and generally would require resolution during FAA certification.

5.2 Electrostatic Charge Hazards

As discussed in detail in Section 2.2, MIL-B-87162 reticulated foam becomes

non-conductive and a potential ignition source for volatile wide cut fuels at

extremely low temperatures. Military experience with previous nonconductive foams has included thousands of such incidents with no aircraft

losses, and aircraft damage limited to several isolated cases of improper foam

installation. This experience, combined with very infrequent use of wide cut

fuels, is sufficient to assess that no hazard potential exists for fully packed

installations of all tanks. Other design alternatives would require additional

hazard assessment as part of certification, as discussed in Section 3.

5.3 Aircondition Pack Bay Temperature and Structure Degradation

All of the foam applications in this report evolve around center wing tanks

with adjacent heat source. The heat source in this discussion is the aircondition pack located underneath the center wing.3
21 July 1998

TG 4: FOAM 37 07/12/987:09 PM

In normal operation the center wing structure acts as a heat sink to dissipate the

heat rejected by the air-condition pack. This heat transfer causes the fuel

inside the fuel tank to heat up and increases the flammability of the fuel vapor.

Although foam installed inside the fuel tank would not act as an insulator to

prevent external heat transfer, and is not expected to significantly affect natural

convection internal heat transfer due to its open cell construction, a significant

reduction in heat transfer could cause some adverse effects such as:

• The pack bay temperature will raise and could trip the over heat detection

system. This will cause nuisance alerts and or dispatch delays.

• The elevated temperature in some aircraft pack bay could reach over 200°

F and this will degrade the strength of the surrounding structure, which is made

of mostly Aluminum.

To minimize this potential thermal problem the pack bay temperature must be

carefully analyzed, tested with the foam installed. And in some case some

source of pack bay ventilation will be required to reduce the pack bay

temperature to an acceptable level. The cost estimate in this report does not

include pack bay ventilation scheme.

5.4 Fuel Contamination and Foam Deterioration

Research into military and very limited civil, experience with reticulated foam

has established three potential mechanisms by which fuel contamination may

become a safety issue. These are:

• Fabrication or installation debris resulting from the initial installation or

replacement.

• Contamination introduced during in-tank maintenance or foam removal

and reinstallation.
21 July 1998

TG 4: FOAM 38 07/12/987:09 PM

• Contamination due to foam deterioration caused by age and environmental

exposure.

Military experience has shown no widespread problems with these types of

contamination. Several sources indicate an absence of problems since

polyether foam was introduced in the mid 1970’s, however, there is evidence,

not well quantified, of occasional occurrences of foam deterioration and a

limited number, on the order of one or two, of incidents of engine flameout

attributed to fuel contamination. Favorable experience has included foam

installed in aircraft without deterioration since the introduction of second

generation polyether foam in the mid 1970’s, satisfactory completion of

laboratory tests on foam which has been installed for extended periods, and

environmental tests required for qualification under extremes of temperature

and humidity. It is reported that contamination symptoms involving a small

proportion of foam combined with a large proportion of other materials are

typically, somewhat incorrectly, attributed to foam. Fuel contamination related

to foam could occur in several ways:

• Contamination can be caused by fabrication residue following initial

installation or replacement. Procedures to prevent or minimize this include

mechanical agitation of the foam blocks after they are cut to remove residue,

multiple fuel system flushing operations combined with fuel cleanliness

checks, and more frequent fuel filter inspections during the initial operation

period following installation. It is noted that there are variations in flushing

procedures among different military units and that those units experiencing the

most problems were using the least thorough procedures.

• Contamination can be caused by failure to protect the foam from external

contamination, either when it is not installed in the aircraft or during in-tank

maintenance. It is absolutely essential that the foam be protected from

contamination during storage and handling. There is evidence that clothing

other than 100% cotton clothing is preferable for in tank maintenance. Cotton
21 July 1998

TG 4: FOAM 39 07/12/987:09 PM

clothing rubbing against foam tends to generate contamination from both, but

primarily from the clothing. The flushing procedures discussed above are also

pertinent. It is typical practice that replacement of more than 25% of the foam

in the tank requires flushing.

• Contamination can be caused by foam deterioration. The ultimate life and

distribution of useful life of modern polyether foam is not known with

certainty. Unfavorable factors include high heat and humidity, including heat

associated with any heat exchangers in the fuel tank. Available information

indicates that continuous exposure to temperatures up to 150° F and

intermittent exposure to temperatures up to 240° F does not cause

deterioration. Available information indicates that these temperatures would

not be exceeded in center wing tanks with adjacent heat sources. It is noted that

information necessary to quantify long term cumulative heat exposure versus

deterioration effects is not available. Contamination is typically first detected

either by particles in fuel filters or during physical inspection inside the tanks.

As previously noted, military experience has not shown significant

deterioration problems, and there has not been established a required

replacement interval. Limited experience in business jets with foam in

fuselage tanks has shown that one model has a required replacement interval of

eight years and that a different model from a different manufacturer has no

replacement interval and no reported problems. The model with the required

replacement interval has shown no overt symptoms of contamination, such as

flameouts or particles in drained fuel or fuel filters or filter bypass indications.

The interval was established by fleet sampling for items such as foam

discoloration and loss of mechanical properties, both of which are normal

tendencies of fuel soaked foam, thus raising the possibility the required

replacement is unnecessarily conservative. It is pertinent to note that the

model involved represents a small fleet (32 aircraft) which may limit the

usefulness of this service experience.
21 July 1998

TG 4: FOAM 40 07/12/987:09 PM

Military aircraft experience most relevant to transport category aircraft is the

experience with C-130 and P-3 aircraft. Of these aircraft, the amount of

experience on the C-130 is far more extensive. AGARD Report No. 771 states

that C-130 experience includes 54 production installations from 1968 to 1970,

85 production installations since 1983, and about 500 retrofit installations.

Although exact details are not available, it is possible to estimate C-130 fleet

experience with foam installed to be on the order of 106 to 107 flight hours.

This experience has included no known accidents, including single or multiple

engine shutdowns, caused by foam related contamination. There is one known

P-3 single engine shutdown associated with early foam contamination and less

rigorous flushing procedures by the unit involved. This experience is

sufficient to conclude that foam related engine shutdowns occur at a much

lower rate than shutdowns due to other causes, and that foam related

contamination is not a common cause event for multiple engine shutdowns

when considering the mitigating factors discussed below.

It is concluded that the potential hazards associated with foam related

contamination and deterioration can be sufficiently mitigated by careful

adherence to cleanliness and flushing procedures, verification of cleanliness

and flushing procedure effectiveness during certification, and careful

inspection of foam condition at major periodic inspections. As additional civil

service history is obtained, it may be possible to justify less extensive

procedures. It is possible that it may be advisable, from an economic risk

standpoint, to replace the foam in a major portion of a fleet during scheduled

major maintenance near the ten year time frame, while a smaller portion would

continue operation to demonstrate continued durability.

5.5 Effects on Other Fuel System Components

Military experience has shown only one adverse effect other than the

occasional contamination problems discussed above, which mainly affect fuel
21 July 1998

TG 4: FOAM 41 07/12/987:09 PM

filters and engine fuel heat exchanges. This effect is erratic fuel quantity

indications when improperly installed foam causes the conductive foam to

contact fuel capacitance probes. This is mainly a problem with traditional low

level alternating current capacitance systems in which the outer probe element

forms part of the circuit, and which typically use exposed probe terminals.

Some newer systems, which do not have these features, are less likely to be

affected. It may be advisable for the design of potentially affected systems to

include retainers to insure positive clearance around fuel quantity probes. This

would not only mitigate any safety hazards associated with this condition, but

it would also eliminate the economic penalty associated with repairing the

condition.

5.6 Corrosion, Water Retention, and Biological Contamination

Concerns are sometimes expressed with regard to the corrosion potential

associated with foam. These concerns include the foam itself rubbing against

the tank structure and protective finish, water retained by the foam, and

biological growth in the water retained by the foam. Extensive military and

limited civil experience has not shown these to be problems, except for one

limited use non-qualified type of foam which was treated for conductivity

improvement following manufacture, and which did cause corrosion problems.

It is important to note that foam does not hold water or fuel like a sponge, and

that there is essentially no known difference in the ability of water in foam to

drain compared to water suspended in fuel. It is further noted that the primary

means to protect against corrosion does not change with the installation of

foam and includes such items as maintaining the integrity of corrosion

protective finishes and adherence to good housekeeping procedures. Based on

this experience, it is concluded that corrosion potential with foam installed

does not exceed that currently experienced and that the installation of foam

does not represent an additional safety hazard.
21 July 1998

TG 4: FOAM 42 07/12/987:09 PM

One further issue is whether foam will increase the amount of water

condensation in the tanks due to the greater surface area exposed to moist air in

the ullage. This phenomenon is most severe when an aircraft cold soaked at

altitude descends into warm moist air, which is drawn in to the tank and comes

into contact with cold interior surfaces. The presence of foam will not change

the amount of moisture subject to condensation or the much larger heat

capacity of structure and fuel compared to air in the ullage. It may, however,

change the rate of condensation, and, therefore, the amount condensed in the

time prior to refueling or natural warming of the structure and fuel. It is

readily observable that cold soaked structure not in direct contact with fuel

warms to ambient temperature much more rapidly than structure in contact

with fuel. This reduces condensation potential and would occur with foam in

the ullage space due to the limited thermal capacity and thermal conductivity

of foam. A severe, but not extreme, case of air at 100° F and 100% relative

humidity contacting tank interior surfaces at 0° F results in condensation of

approximately .05 pound of water per pound of dry air if 100% condensation

occurs. If the tank is 10% full of fuel, this results in a volumetric water

concentration of .055% water in the fuel, compared to the sump capacity of

.10% of entire tank volume required by FAR 25.971. This water concentration

is higher than the .02% free water specified for fuel icing by FAR 25.951 but

would be reduced to within this limit by refueling or removal of the water

through sump drains. It is, therefore, concluded that any additional water

condensation does not constitute a safety hazard, however, additional research

would be required if it were necessary to determine the rate and exact amount

of such condensation.

5.7 Other Equipment Hazards or Effects

This type of hazard is related to the fire hazards to ground equipment and

facilities associated with handling and storage of fuel wetted foam when it is
21 July 1998

TG 4: FOAM 43 07/12/987:09 PM

removed from the aircraft. It has been previously discussed, and is sufficiently

mitigated by use of designated storage equipment and facilities and use of

standard fire protection procedures.
21 July 1998

TG 4: FOAM 44 07/12/987:09 PM

7.0 Overall Safety Assessments

Based on the historical record, foam was assessed as effective in four

operational overpressure events and of unknown effectiveness in four

operational overpressure events also involving breach of tank integrity and

external fire. Negative effects over this time period would include potential for

five additional accidents due to increased flights based on the .016/million

departure rate and the 317 million departures for the airline transport fleet.

Factors, which could improve the overall foam safety effectiveness, include the

possibility that foam would be effective in some or all of the unknown events.

Factors which could degrade the overall foam safety effectiveness would

include the possibility of events caused by those negative factors previously

discussed, which were assessed as very low-non-quantifiable hazards that

could be sufficiently mitigated, or the possibility that reduced range would, in

fact, have negative safety effect.

The above overall safety assessment applies primarily to airline transport

aircraft, of approximately 100 seats or more in size, in primarily Part 121

operations. An overall assessment based on the historical record for regional

airline aircraft and business jets would be entirely negative due to the absence

of any historical overpressure events. It is acknowledged that these aircraft

have had less fleet operating time exposure, by perhaps an order of magnitude.

If it were assumed that an overpressure event were to occur in the near future,

the overall safety assessment for aircraft losses would be similar to that for

airline transport aircraft, although fatalities to the traveling public would be

lower for regional aircraft and much lower for business jet aircraft. It is also

possible, however, that the absence of overpressure events may be due to other

design and operational factors beyond the scope of this report. It is, therefore,

not possible to conclude that foam installation would produce positive effects

for regional transport and business jet aircraft. It is noted, however, that these
21 July 1998

TG 4: FOAM 45 07/12/987:09 PM

aircraft may have reduced susceptibility to any potential hazards associated

with reduced range, due to the greater tendency to fly multiple flight legs

without refueling, for operational and economic reasons, and the resulting

greater fuel reserves on many flight legs.
21 July 1998

TG 4: FOAM 46 07/12/987:09 PM

8.0 Cost Analysis

The two types of material, which evaluated for cost, in this report are: Foam

with 100% filled and Expanded Metal Products. Both are installed on aircraft

center wing tank with adjacent heat source. Two classes of aircraft are

considered in this cost for the 2 types of material. The first one is retrofit cost

for aircraft that are in service and the second is for new and or production

aircraft.

The cost is broken down into nonrecurring and recurring cost.

Nonrecurring Cost

The nonrecurring cost is made up of:

• Engineering

• Tooling and Planning

• Test and certification

• Operation and Customer Support

• Material (Foam requires replacement each 15 year period)

• Cost of disposal of material

• Infrastructure is the storage facility required to store foam or expanded

metal during maintenance.

Recurring Costs

• The recurring cost is made up of:

• Fuel burn cost to carry the added weight
21 July 1998

TG 4: FOAM 47 07/12/987:09 PM

• Additional maintenance cost

• Loss of revenue when aircraft operate at maximum weight limit and or fuel

capacity.

The next four tables provide a complete cost structure for the 2 types of

material used on the two classes of aircraft
21 July 1998

TG 4: FOAM 48 07/12/987:09 PM

Foam for Inservice Aircraft

One time cost Large Medium Small

Development $10,546 $5,536 $3,430

Installation $345,147 $154,559 $57,234

Infrastructure $35,047 $27,332 $3,497

Total Per Aircraft $390,740 $187,427 $64,191

Total Effected Aircraft $501,710,160 $205,607,419 $394,525,989

Total Industry Cost $1,101,843,568

Annual Recurring

Foam Replacement $23,239 $10,395 $3,843

Additional Fuel Burn $66,453 $22,216 $7,202

Loss of Revenue $1,455,773 $596,726 $99,739

Additional Maintenance $38,656 $24,160 $9,664

Total per Aircraft $1,584,121 $653,497 $120,448

Total effected Aircraft $2,034,011,364 $716,886,209 $740,634,752

Total Industry Cost $3,491,532,325
21 July 1998

TG 4: FOAM 49 07/12/987:09 PM

Foam for Production Aircraft

One time cost Large Medium Small

Development $8,210 $4,169 $2,536

Installation $310,627 $134,833 $48,603

Infrastructure $35,047 $27,332 $3,497

Total Per Aircraft $353,884 $166,334 $54,636

Annual Recurring

Foam Replacement $23,239 $10,395 $3,843

Additional Fuel Burn $66,453 $22,216 $7,202

Loss of Revenue $1,455,773 $596,726 $99,739

Additional Maintenance $38,656 $24,160 $9,664

Total per Aircraft $1,584,121 $653,497 $120,448
21 July 1998

TG 4: FOAM 50 07/12/987:09 PM

Expanded Metal Products for Inservice Aircraft

One time cost Large Medium Small

Development $11,581 $6,186 $3,869

Installation $801,645 $332,539 $105,239

Infrastructure $35,047 $27,332 $3,497

Total Per Aircraft $848,273 $366,057 $112,605

Total Effected Aircraft $1,089,182,532 $401,564,529 $692,408,145

Total Industry Cost $2,183,155,206

Annual Recurring

Additional Fuel Burn $72,917 $24,377 $7,899

Loss of Revenue $1,217,444 $490,414 $71,429

Additional Maintenance $38,656 $24,160 $9,664

Total per Aircraft $1,329,017 $538,951 $88,992

Total effected Aircraft $1,706,457,828 $591,229,247 $547,211,808

Total Industry Cost $2,844,898,883
21 July 1998

TG 4: FOAM 51 07/12/987:09 PM

Expanded Metal Products for Production Aircraft

One time cost Large Medium Small

Development $9,245 $4,819 $2,975

Installation $767,124 $312,813 $96,609

Infrastructure $35,047 $27,332 $3,497

Total Per Aircraft $811,416 $344,964 $103,081

Annual Recurring

Additional Fuel Burn $72,917 $24,377 $7,899

Loss of Revenue $1,217,444 $490,414 $71,429

Additional Maintenance $38,656 $24,160 $9,664

Total per Aircraft $1,329,017 $538,951 $88,992
21 July 1998

TG 4: FOAM 52 07/12/987:09 PM

8.1 Assumptions

• Foam requires replacement every 15 years.

• Cost to destroy foam is the same as cost to destroy jet fuel at 79 cents /lb.

• 2 days for down time is estimated for installation. Cost is estimated as the

cost of money for this period.

• 1 day added to production span time for installation of foam on production

aircraft - Cost is estimated as the cost of money for this period.

• Development cost per aircraft is the development cost per model multiplied

by the number of models, and divided by the number of aircraft with heated

center wing tanks.

• Aluminum mesh and foam costs provided by vendors (aluminum mesh

costs approximate 3 times more than foam)

• Fuel cost is 62 cents per gallon.

• Annual fuel burn cost is computed using the cost estimator spreadsheet

provided by Task Group 8.

• Loss of revenue is computed using the cost estimator spreadsheet provided

by Task Group 8.

• Interest rate is 7%

• Loss of revenue is calculated using long mission flights. The assumption is

50% of flights are weight limited and 50% are fuel limited.

• Cost information in this report is only for aircraft with center wing tank

with adjacent heat source.

• Storage facility cost is estimated at $150,000, $100,000 and $75,000 for

large, medium and small aircraft respectively.

• There are 100, 100 and 150 maintenance bases for large, medium and small

aircraft respectively.

• Three storage facilities are required at each base.

END
Fuel Vapor Reduction

Task Group 5

Aviation Rulemaking

Advisory Committee

ARAC

JAA FAA

THE PUBLIC
6 July 1998

Task Group 5 – Fuel Vapour Reduction ABSTRACT

1. ABSTRACT

The FAA/JAA initiated a Fuel Tank Harmonisation Working Group in January

1998 by the issuance of a Harmonisation Terms of Reference entitled

“Prevention of Fuel Tank Explosions” on December the 16th 1997.

The Working Groups stated task was to study means to mitigate or eliminate fuel

tank flammability and to propose regulatory changes to the FAA/JAA Aircraft

Rulemaking Advisory Committee (ARAC).

The Working Group established eight Task Groups to report on the following:

1. Service History and Safety Assessment

2. Explosion Suppression

3. Fuel Tank Inerting

4. Fuel Tank Foam

5. Evaluation and mitigation of Fuel Tank Exposure to Flammable

Fuel Vapours

6. Fuel Properties Aircraft Effects

7. Fuel Properties Infrastructure Effects

8. Evaluation Standards Advisory and Proposed Regulation Action

This document is the report of Task Group Five whose tasks were:

(i) To evaluate the present exposure of aeroplane fuel tanks to

flammable fuel vapour.

(ii) To assess means of mitigating the exposure of aeroplane fuel

tanks with adjacent heat sources to flammable fuel vapour.

(iii) To evaluate the exposure of aeroplane fuel tanks to flammable fuel

vapour by changing the fuel flashpoint modifications proposed by

Task Group Five, or other Task Groups.

Task Group Five had six principle members coming from across the aeronautical

transport industry.

ß Propulsion Systems Design Manager Aerospatiale

ß Senior Fuel Systems Engineer Airbus Industrie

ß Chemical Engineer, Fuel Systems Safety Boeing

ß Senior Engineer, Aircraft and Systems Safety British Airways

ß Propulsion/Thermodynamics Staff Scientist Gulfstream

ß Independent Transportation Safety Consultant TRC

Numerous personnel within the six principle members own organisations, other

Task Groups and members of the aeronautical transport industry worked for and

or contributed to this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 1 of 93

2. SUMMARY

This report attempts to quantify the exposure of fuel tanks to flammable vapour

and evaluate methods to mitigate the exposure considering the related impacts:

safety, certification, environmental, aeroplane design, operational and cost.

Analysis has also been performed to assess the effects of ground inerting and

changing the fuel flashpoint specification in mitigating the exposure to flammable

vapours (see reports of Task Groups 6/7 and 3 for the impacts of these

modifications). This analysis has been completed for generic aeroplanes and

therefore does not relate to any specific aeroplane design.

Thermal analysis has shown that all generic fuel tanks have some exposure to

flammable fuel vapour.

• Tanks without adjacent heat sources, independent of location, (wing or

fuselage), have equivalent exposure of approximately 5%.

• Tanks with adjacent heat sources have exposure of approximately 30%.

Other factors affecting exposure are:

• Ambient temperature (of which control is not possible)

• Fuel loading (which is discussed further, see option 3)

• Altitude (which is not discussed within this report)

Following from the above, thirteen methods of mitigating the effects of heat

sources adjacent to fuel tanks have been analysed. Only one eliminates

exposure to fuel vapours. This is achieved by disabling the fuel tank and thus

has severe operational consequences that can only be evaluated for individual

airlines operations, and thus no conclusion is provided within this report.

Five options considered reduce the exposure to flammable fuel vapour, and

have been evaluated for the Small, Medium and Large transport Aeroplanes:

1. Insulate the heat source adjacent to fuel tanks

2. Ventilate the space between fuel tanks and adjacent heat sources

3. Redistribute mission fuel into fuel tanks adjacent to heat sources

4. Locate significant heat sources away from fuel tanks.

5. Sweep the ullage of empty fuel tanks

Options 2 and 4 have been shown to reduce the exposure of fuel tanks with

adjacent heat sources to a level similar to fuel tanks without adjacent heat

sources. (Option 4 is only applicable to new aeroplane designs).

Option 5 requires significant further research before a conclusion on its

feasibility can be reached.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 2 of 93

Table 2.1 summarises the effects and impact of the five options.

In addition the effects of ground inerting and changing the fuel flashpoint were

assessed. Either method could reduce the exposure of fuel tanks with adjacent

heat sources to a level similar to fuel tanks without adjacent heat sources.

Table 2.2 summarises the effects on exposure of ground inerting, changing the

flash point specification, and some potential combinations of modifications (that

could be evaluated in the timeframe available).

Table 2.1 Summary of impacts and applicability of the five methods evaluated

Centre Wing Tanks With Adjacent Heat Sources

Exposure to Flammable Vapours 30%

Fuel Tanks Without Adjacent Heat Sources

Exposure to Flammable Vapours 5 %

OPTION

IMPACT

1.

Insulate

Heat

Sources

2.

Ventilate

(Directed)

3.

Redistribute

Fuel

4.

Locate

Heat

Sources

5.

Sweep

Ullage

Estimated Exposure to

Flammable Vapours

after Modification

20% 5% 20% 5%

Not

quantified

New safety Concerns minor None Medium none Medium

Certification Impact minor Minor Minor none MAJOR

Environmental Impact none None None none YES

Aeroplane Impact minor Medium Minor MAJOR Medium

Operational Impact minor Minor MAJOR minor MAJOR

One Time Small

Fleet Costs Medium

($ x 106) Large

160

50

100

500

60

300

4

2

3

160

50

100

2,000

650

1,200

Annual Fleet Small

Costs Medium

($ x 106) Large

10

2

2

170

20

70

7

3

14

?

?

?

370

80

180

10 Year Fleet Costs

($ x 106)

450 3,500 250 ? 10,000

Applicability MOST MOST MOST NEW

DESIGNS

MOST
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 3 of 93

Table 2.2 Summary of the effects of changing the fuel flashpoint, ground inerting

and combinations of different modifications.

Modification

Wing Tanks

Without heat

sources

Centre Tanks

without heat

sources

Centre Tanks

with heat

sources

Current Aeroplanes 5% 5% 30%

120°F Flashpoint Fuel

130°F Flashpoint Fuel

140°F Flashpoint Fuel

150°F Flashpoint Fuel

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

10 to 20%

5 to 10%

1 to 5%

1%

Ground Based Inerting

of Fuel Tanks

Not applicable < 1% 1%

Combinations of

Modifications

Direct Ventilate and

120°F

Not applicable Not applicable < 1%

Insulate and 120°F Not applicable Not applicable 5%

Insulate and 130°F Not applicable Not applicable 1%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 4 of 93

3. TABLE OF CONTENTS

1. ABSTRACT

2. SUMMARY

3. TABLE OF CONTENTS

4. INTRODUCTION

4.1. Objective

4.2. Scope

4.3. Assumptions, Definitions and Limitations

5. EVALUATION OF EXPOSURE TO FLAMMABLE VAPOURS

5.1 Thermal Modelling

5.2 Exposure Analysis

6. METHODS CONSIDERED

6.1. Reducing the Evolution of Fuel Vapours

6.1.1. Controlling Temperature

6.1.1.1. Insulate Fuel Tanks From Heat Sources

6.1.1.2. Insulate Heat Sources Adjacent to Fuel Tanks

6.1.1.3. Ventilate Heat Sources Adjacent to Fuel Tanks

6.1.1.4. Ventilate the Space Between Fuel Tanks and Adjacent

Heat Sources

6.1.1.5. Redistribute Mission Fuel Into Fuel Tanks Adjacent to

Heat Sources

6.1.1.6. Locate Significant Heat Sources Away From Fuel

Tanks

6.1.2. Cooling

6.1.2.1. Cool the Fuel During Refuelling

6.1.2.2. Cool the Fuel in the Fuel Tanks

6.1.2.3. Cool the Heat Sources Adjacent to Fuel Tanks

6.1.3. Controlling Pressure

6.1.3.1. Pressurise the Fuel Tanks

6.2. Eliminating the Ullage

6.2.1. Actively Minimise the Ullage space

6.2.2. Remove Residual Fuel from Unused Fuel Tanks

6.3. Sweeping the Ullage

6.3.1. Sweeping the Ullage of Empty Tanks

7. METHODS SELECTED FOR FURTHER EVALUATION

7.1. Insulate Heat Sources Adjacent to Fuel Tanks

 7.2. Ventilate the Space Between Fuel Tanks and Adjacent Heat Sources

7.3. Redistribute Mission Fuel Into Fuel Tanks Adjacent to Heat Sources

7.4. Remove Heat Sources Adjacent to Fuel Tanks

 7.5. Sweeping the Ullage of Empty Tanks
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 5 of 93

TABLE OF CONTENTS (Continued)

8. INSULATE HEAT SOURCES ADJACENT TO FUEL TANKS

8.1. Safety Impact

8.2. Certification Impact

8.3. Environmental Impact

8.4. Aeroplane Impact

8.5. Operational Impact

8.6. Cost Impact

9. VENTILATE THE SPACE BETWEEN FUEL TANKS AND ADJACENT

HEAT SOURCES

9.1. Safety Impact

9.2. Certification Impact

9.3. Environmental Impact

9.4. Aeroplane Impact

9.5. Operational Impact

9.6. Cost Impact

10.REDISTRIBUTE MISSION FUEL INTO FUEL TANKS ADJACENT TO

HEAT SOURCES

10.1. Safety Impact

10.2. Certification Impact

10.3. Environmental Impact

10.4. Aeroplane Impact

10.5. Operational Impact

10.6. Cost Impact

11.LOCATE SIGNIFICANT HEAT SOURCES AWAY FROM FUEL TANKS

11.1. Safety Impact

11.2. Certification Impact

11.3. Environmental Impact

11.4. Aeroplane Impact

11.5. Operational Impact

11.6. Cost Impact

12.SWEEP THE ULLAGE OF EMPTY FUEL TANKS

12.1. Safety Impact

12.2. Certification Impact

12.3. Environmental Impact

12.4. Aeroplane Impact

12.5. Operational Impact

12.6. Cost Impact
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 6 of 93

TABLE OF CONTENTS (Continued)

13.CONCLUSIONS

14.REFERENCES

15.APPENDIX

15.1 Thermal Model Descriptions

15.1.1 Centre Wing Tank (Large Aeroplane)

15.1.2 Main Wing Tank (Small and Large Aeroplane)

15.1.3 Centre Wing Tank (Small Aeroplane)

15.1.4 Main Wing Tank (Medium Aeroplane)

15.1.5 Centre Wing Tank (Medium Aeroplane)

15.1.6 Main Wing Tank (Business Jet and Regional Turbofan)

15.1.7 Centre Wing Tank (Additional Small Aeroplane)

15.1.8 Centre Wing Tank (Regional Turbofan)

15.2 Thermal Model Predicted Fuel Temperatures Results Charts

15.2.1 Large Aeroplane Wing Tank

15.2.2 Small Aeroplane Wing Tank

15.2.3 Business Jet Wing Tank

15.2.4 Regional Turbofan Wing Tank

15.2.5 Medium Aeroplane Wing Tank

15.2.6 Small Aeroplane Centre Wing Tank (without heat source)

15.2.7 Regional Turbofan Centre Wing Tank (without heat source)

15.2.8 Large Aeroplane Centre Wing Tank (with heat source)

15.2.9 Small Aeroplane Centre Wing Tank (with heat source)

15.2.10 Medium Aeroplane Centre Wing Tank (with heat source)

15.3 Exposure Analysis Results Charts

15.3.1 Large Aeroplane Wing Tank

15.3.2 Small Aeroplane Wing Tank

15.3.3 Business Jet Wing Tank

15.3.4 Regional Turbofan Wing Tank

15.3.5 Small Aeroplane Centre Wing Tank (without heat source)

15.3.6 Regional Turbofan Centre Wing Tank (without heat source)

15.3.7 Large Aeroplane Centre Wing Tank (with heat source)

15.3.8 Small Aeroplane Centre Wing Tank (with heat source)

15.3.9 Medium Aeroplane Centre Wing Tank (with heat source)

15.3.10 Large Aeroplane Centre Wing Tank With Insulation

15.3.11 Large Aeroplane Centre Wing Tank With Ventilation

15.3.12 Large Aeroplane Centre Wing Tank With Redistributed Fuel

15.3.13 Large Aeroplane Centre Wing Tank With 120°F Flashpoint

15.3.14 Large Aeroplane Centre Wing Tank With 130°F Flashpoint

15.3.15 Large Aeroplane Centre Wing Tank With 140°F Flashpoint

15.3.16 Large Aeroplane Centre Wing Tank With 150°F Flashpoint
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 7 of 93

TABLE OF CONTENTS (Continued)

15.3.17 Medium Aeroplane Centre Wing Tank With 120°F Flashpoint

15.3.18 Medium Aeroplane Centre Wing Tank With 130°F Flashpoint

15.3.19 Medium Aeroplane Centre Wing Tank With 140°F Flashpoint

15.3.20 Medium Aeroplane Centre Wing Tank With 150°F Flashpoint

15.3.21 Small Aeroplane Centre Wing Tank With 120°F Flashpoint

15.3.22 Small Aeroplane Centre Wing Tank With 130°F Flashpoint

15.3.23 Small Aeroplane Centre Wing Tank With 140°F Flashpoint

15.3.24 Small Aeroplane Centre Wing Tank With 150°F Flashpoint

15.3.25 Large Aeroplane Centre Wing Tank COMBINATION of

Insulate Heat Sources AND 120°F Flashpoint

15.3.26 Large Aeroplane Centre Wing Tank COMBINATION of

Insulate Heat Sources AND 130°F Flashpoint

15.3.27 Large Aeroplane Centre Wing Tank With Ground Inerting

15.4 Exposure Analysis Process

15.5 Ullage Sweeping Testing
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 8 of 93

4. INTRODUCTION

4.1. Objective

The objective of this report is to quantify the exposure of fuel tanks to flammable

vapour and to discuss different methods by which that exposure can be

minimised including the related; safety, certification, environmental, aeroplane,

operational and cost impacts.

4.2. Scope

The methods of reducing the exposure considered are:

(a) Minimise Effects of Onboard Heat Sources

(b) Cooling

(c) Pressurisation

(d) Eliminating the Ullage

(e) Sweeping Ullage

This report does not concern itself with:

(i) The safety, certification, environmental, aeroplane, operational and

cost impacts of the reduction of oxygen concentration, e.g. nitrogen

inerting, (see Task Group 3 report).

(ii) The safety, certification, environmental, aeroplane, operational and

cost impacts of the change to the specification of flash point for JET

A/A1, (see Task Group 6 report).

(iii)Ignition sources (see the terms of reference for this ARAC FTHWG).
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 9 of 93

4.3. Assumptions, Definitions and Limitations

For the purposes of this report in order to quantify the exposure of fuel tanks to

flammable vapour the following assumptions and limitations have been made:

(a) The lower flammability limit in terms of fuel vapour concentration in air is

defined as 0.6% by volume or 0.35% by mass (reference “Handbook of

Properties of Common Petroleum Fuels”).

(b) The lower flammability limit in terms of temperature, (as defined by the

fuel flash point as defined in the specification of JET A/A1 fuel, (reference

ASTM D56)), is used as the basis for quantifying the flammability of fuel

vapour and hence the flammability of fuel tanks.

(c) The fuel flash point, (as defined above), is assumed to decrease linearly

at the rate of 1°F for every 800ft increase in altitude, (1°C for every 439m

increase in altitude), (reference “Handbook of Aviation Fuel Properties”,

published by the Co-ordinating Research Council Inc.).

* (The definition and assumption stated above, (a), (b) and (c) cover static

conditions).

(d) Investigations into dynamic flammability of fuel have been performed with

no consistent or conclusive definition at the date of writing this report.

Therefore dynamic conditions have not been used to quantify the

exposure of fuel tanks to flammable fuel vapour.

(e) Probability profiles of ambient static air temperatures, based on historical

measurements, have been used, (reference Task Group 8).

(f) The ground refuel temperature is assumed to be the same as the ambient

air temperature.

(g) The distribution of JET A/A1 flash points has been compiled from

petroleum industry data, (reference Task Group 6/7).

(h) The world fleet of aeroplanes has been divided into size categories,

(reference Task Group 8).

(i) For each of these generic aeroplane categories, fuel tank volumes, fuel

usage and flight profiles have been defined for the thermal model

analysis.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 10 of 93

5. EVALUATION OF EXPOSURE TO FLAMMABLE VAPOURS

5.1 Thermal Modelling

To quantify the current fleet exposure of fuel tanks to flammable vapour a

process was developed to quantify the amount of time that the fuel temperature

is above the flash point of the fuel on a fleet wide basis.

To predict fuel temperatures, the worldwide fleet of transport aeroplanes was

divided into six generic size categories of aeroplanes (from Task Group 8). A

representative aeroplane from each of the six categories was then chosen for

development of a specific thermal model. The choice aeroplane to model was

dependent upon three factors:

1. Availability of an existing thermal model, (preference given to those

validated by flight test).

2. Number of aeroplanes that model represents in that size category.

3. Involvement in past events, (from Task Group 1).

For the Large and Small aeroplane, both the main wing tanks and the centre

wing tank were modelled. For the Medium aeroplane a model was developed for

the centre wing tank and results from an inactive model were available for the

main wing tanks. A second Small aeroplane was also modelled, which had a

centre wing tank without adjacent heat sources. A matrix of the aeroplane sizes

and fuel tank configurations modelled is shown Table 5.1.

Table 5.1 Aeroplane sizes and fuel tank configurations modelled

Large Main Wing Tank Centre Wing Tank

(with adjacent heat

source)

(no thermal model

results available)

Medium Main Wing Tank

(inactive model)

Centre Wing Tank

(with adjacent heat

source)

(no thermal model

results available)

Small Main Wing Tank Centre Wing Tank

(with adjacent heat

source)

Centre Wing Tank

(without adjacent

heat source)

Regional

Turbofan

Main Wing Tank (no thermal model

results available)

Centre Wing Tank

(without adjacent

heat source)

Regional

Turboprop

(no thermal model results available)

Business

Jet

Main Wing Tank (not applicable)
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 11 of 93

5.1 Thermal Modelling (cont.)

The thermal models were developed independently by six different aeroplane

manufacturers using seven different thermal codes, and therefore represent a

wide range of complexity, from simple differential equation solutions to onedimensional heat transfer balances, to complex finite element fluid/thermal

codes. Because of this wide diversity, the assumptions made in each model

were not always the same, but are documented in the descriptions of each

thermal model in the Appendix in section 15.1, (with the exception of the Medium

aeroplane main wing tank).

In order to produce consistent results, the inputs to and results from each model

were processed through Task Group 5 and Task Group 8.

Each model was run through three generic flight profiles representing short,

medium and long missions for that size aeroplane. Each flight profile included

altitude, Mach number, fuel remaining in each tank and body angle as a function

of time. Each model was then run for seven cases, for each mission length,

representing a wide range of ambient temperature conditions. The seven

ambient temperature profiles ranged from cold (1% cumulative probability) to

extremely hot (99.9% cumulative probability). Each model therefore ran a total of

21 cases for each aeroplane/tank configuration and the results, (predicted fuel

temperature profiles versus time), were then formatted in a consistent manor.

(For the Medium aeroplane main wing tank the model was no longer active and

so the 21 cases above could not be run. The data available covered four

representative missions with two fuel temperatures and two ambient air

temperatures. This data was used to do a simple comparison to verify that the

main wing tanks of the Medium aeroplane have a similar exposure to the Large

and Small aeroplanes. The exposure analysis, described below was not applied

to this model).
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 12 of 93

5.2Exposure Analysis

To quantify the current fleet exposure of the fuel tanks to flammable vapour, a

process was developed to quantify the amount of time that the fuel temperature

is above the flash point of the fuel on a fleet wide basis.

A statistical process was developed using three key variables; mission length,

fuel temperature, and flash point, all of which have a defined distribution.

Mission length - Task Group 8 used current fleet statistics to predict the

percentage of flights for the three mission lengths, for each size aeroplane. For

example; the large aeroplane fleet is estimated to have 63% short missions, 25%

medium missions, and 12% long missions, (see Chart 5.2.1).

Chart 5.2.1 Distribution of Mission Lengths (Large Aeroplane)

Fuel temperature - The air ambient temperature profiles used as thermal model

inputs were derived from ground and in-flight atmospheric data, based on the

probability of a flight encountering that ambient condition, (see Chart 5.2.2).

Chart 5.2.2 Fleetwide Distribution of Ambient Ground and Cruise Temperatures

0%

25%

50%

75%

100%

-80 -60 -40 -20 0 20 40 60 80 100 120

Ambient Temperature (F)

Cummulative Probability

Ground Temp (F)

Cruise Temp (F)

0

200

400

600

800

1,000

1,200

1,400

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000

MISSION LENGTH (N.Miles)

NUMBER OF FLIGHTS
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 13 of 93

It can be seen that the distribution of ground temperatures is broader than the

distribution of cruise temperatures. Seven points on the distributions, (as

shown), were chosen to represent a wide range of conditions. Profiles were

developed for these conditions. (See Table 5.2.3 below).

Table 5.2.3 Distribution of Ground and Cruise Ambient Temperatures

Condition of Day Cumulative

Probability

Ground Temp

Sea Level

Cruise Temp

35,000 feet

Very Cold 1% -8°F -78°F

Cold 25% 37°F -60°F

Average 50% 57°F -53°F

Warm 75% 72°F -45°F

Hot 95% 90°F -38°F

Very Hot 99% 100°F -33°F

Extremely Hot 99.9% 111°F -27°F

For each aeroplane mission, the seven ambient temperature profiles versus time

were developed. For example; the Business Jet – Short Mission ambient

temperature profiles are shown below in chart 5.2.4.

Chart 5.2.4 Business Jet – Short Mission. Range of Ambient Temperatures

Using these ambient temperature profiles as the input to the thermal model, the

output from the thermal model will also be a range of fuel temperatures. The

results will be seven profiles with the same probabilities as the ambient

temperature profiles. For example; the fuel temperature profiles predicted from

the Business Jet – Short Mission thermal model are shown in Chart 5.2.5.

-100

-80

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

TIME (HOURS)

AMBIENT TEMPERATURE (F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FEET)

Extremely Hot 99.9%

Very Hot 99%

Hot 95%

Warm 75%

Average 50%

Cool 25%

Very Cold 1%

ALTITUDE
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 14 of 93

Chart 5.2.5 Business Jet – Short Mission. Predicted Fuel Temperatures for a

Range of Ambient Temperatures

Flash point - To define the flash point of the fuel, the initial assumption was to

use the specification limit of 100°F. However, as the objective was to define the

exposure of the current fleet of aeroplanes as they actually operate, it was

decided to increase the accuracy of the analysis by using the flash point of the

fuel that is loaded onto the aeroplane. Task Group 6 provided data on the

current distribution of flash points delivered worldwide and assigned probabilities

of a specific mission being fuelled with a fuel at a specific flash point. See Chart

5.2.6 below.

Chart 5.2.6 Fleetwide Distribution of Fuel Flashpoint

Task Group 5 then used this data to derive the flashpoint versus time profiles

that correspond to each fuel temperature profile, for each mission profile of each

aeroplane tank configuration. For example; the Business Jet – Short Mission

flashpoint profiles are shown in Chart 5.2.7.

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT)

99.9%

99%

95%

75%

50%

25%

1%

ALTITUDE

0%

25%

50%

75%

100%

100 105 110 115 120 125

Fuel Flash Point Temperature (F)

Cummulative Probability
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 15 of 93

Chart 5.2.7 Business Jet – Short Mission. Range of Fuel Flashpoints

The next step was to over lay the fuel temperature profiles with the

corresponding flashpoint profiles for each mission profile and for each aeroplane

tank configuration. For example; the Business Jet – Short Mission profiles are

shown in Chart 5.2.8.

Chart 5.2.8 Business Jet – Short Mission. Predicted Fuel Temperatures for a

Range of Ambient Temperatures and Flashpoints.

0

20

40

60

80

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL FLASH POINT TEMPERATURE 

(F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FEET)

FP = 5%

FP = 25%

FP = 50%

FP = 75%

FP = 95%

ALTITUDE

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT)

1% 25%

50% 75%

95% 99%

99.9% FP = 5%

FP = 25% FP = 50%

FP = 75% FP = 95%

ALTITUDE
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 16 of 93

The time of exposure can be visualised by looking at the part of the mission

where the band of fuel temperature lines (filled in symbols) are above the band

on flash point line (open symbols). Another way to visualise the time of

exposure is to focus only on the overlap of the two solid lines representing the

average fuel temperature and the average flash point.

To quantify the fleet exposure, a statistical analysis approach was applied to a

statistically significant number (10,000) of randomly selected flights. The flights

were then selected to be representative of the fleet using the defined

distributions of the three variables. For example, flight one may be a short

mission on a cold day with an average flash point fuel, and flight two may be a

long mission on an average day with a low flash point fuel, and on and on until

10,000 flights have been defined in this manner. For every one of the 10,000

flights, the time that the fuel temperature was above the flash points was

calculated.

These statistical analysis results are best displayed in the form of a histogram

showing the number of flights at each percentage of flight time. For example; a

histogram the Business Jet which accounts for all three mission lengths is shown

in Chart 5.2.9.

Chart 5.2.9 Histogram of 10,000 Business Jet Flights

(Average exposure 5.6%)

Averaging the results for all 10,000 flights provides an average percentage of

the flight time that any particular flight could be expected to be exposed to a fuel

temperature above the fuel flash point. These fleet average exposure results

are given for each aeroplane size/tank configuration in table 5.2.10.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 17 of 93

Table 5.2.10 Exposure Analysis Results For Centre and Wing Tanks

Wing Tanks CentreTanks

WITHOUT

adjacent heat

sources

WITHOUT

adjacent heat

sources

WITH

adjacent

heat sources

WITH adjacent

heat sources and

directed ventilation

large small regional

turbofan

bizjet small regional

turbofan

large small medium

5% 5% 30% 5%

(Due to differences between the various thermal models and thus differences in

the possible errors in calculation the analysis results have been rounded to

within 5%).

Once the current fleet exposures to fuel tanks with flammable vapours are

calculated, the same method of thermal analysis is used to systematically study

methods to reduce the exposure in fuel tanks. 
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 18 of 93

6. METHODS CONSIDERED

6.1. Reducing the Evolution of Fuel Vapours

Fuel flammability is dependent upon fuel vapour-air ratios which are a function

of temperature and pressure. Therefore by controlling either of these two

parameters the flammability of fuel tanks can be manipulated. The methods

considered in this section are therefore separated between controlling

temperature, (6.1.1. and 6.1.2.), and controlling pressure, (6.1.3.), (the control of

temperature is sub-divided into minimising the effects of heat sources, (6.1.1.),

and active cooling, (6.1.2.).

6.1.1. Controlling Temperature

These methods have only been considered for Large, Medium and Small jet

transport aeroplanes as these are the only aeroplanes identified by Task Group

One as having centre wing tanks with adjacent heat sources.

6.1.1.1. Insulate Fuel Tanks from Adjacent Heat Sources

For fuel tanks located in aeroplane wings, apart from solar radiation, they are

not materially affected by heat sources therefore the insulation of these tanks is

not considered appropriate. However for centre wing tanks with adjacent heat

sources, insulation is considered.

Thermal analysis shows that the benefits that could be achieved on the ground

by thermal insulation of the bottom surface of centre wing tanks, (reducing the

heating effects from air-conditioning packs, e.t.c.), would be offset by the lower

cooling rate experienced in flight, (prolonging the exposure during flight).

Due to;

a) the questionable benefits such a modification would provide

b) a comparison to other options discussed in this report

this option is not considered further within this report.

6.1.1.2. Insulate Heat Sources Adjacent to Fuel Tanks

Insulation of heat sources adjacent to centre wing tanks would reduce the

heating of the contained fuel on the ground without being detrimental to the

cooling of that fuel in flight. The potential modifications could be relatively simple

to design and retrofit onto many, (but not all), existing aeroplanes, however the

affect on the operation of the systems insulated requires specific evaluation.

Thermal analysis predicts this modification will reduce the exposure of the Large

generic centre wing tank from 27% to 19%.

The benefits of this method of reducing the heating effects on the centre

wing tank are considered further by means of thermal analysis within

section 8 of this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 19 of 93

6.1.1.3. Ventilate Heat Sources Adjacent to Fuel Tanks

Ventilation of heat sources with ambient air in flight will reduce the heating of the

fuel tank. Thermal modelling and flight testing on a large aeroplane has shown

that this method provides only minimal reductions in fuel temperature. Thermal

analysis predicts this modification will reduce the exposure of the Large generic

centre wing tank from 27% to 22%.

The analysis suggests that for a ventilation system to be effective, it must

operate on the ground with a cooler source of air and must be directed

effectively between the heat source and the fuel tank. (See section 6.1.1.4.).

Due to;

a) the results of thermal analysis

b) a comparison to 6.1.1.4. discussed in this report

this option is not considered further within this report.

6.1.1.4. Ventilate the Space Between Fuel Tanks and Adjacent Heat

Sources

Directed forced ventilation in the space between heat sources and fuel tanks is

implemented on some aircraft today to limit the temperature of the aircraft

structure. The cooling effect is equally effective on the ground and flight. The

systems presently used are simple in principle, but implementation on existing

aeroplanes, which do not have such a system, would require significant

modifications.

Thermal analysis predicts the exposure of the Medium generic centre wing tank

with this modification will be 4%.

The benefits of this system in reducing the heating effects of the centre

wing tank are considered further by means of thermal analysis within

section 9 of this report.

6.1.1.5. Redistribute Mission Fuel into Fuel Tanks Adjacent to Heat

Sources

Increasing the quantity of fuel uplifted into the centre wing tank has been shown,

by thermal analysis, to slow the effective rate of temperature increase of the

contained fuel on the ground. This approach could involve significant changes

to the operation of the aeroplane and require re-examination of the aeroplane

strength criteria, which affects the effective life of an aeroplane.

The benefits of this method in reducing the heating effects in the centre

wing tank are considered further by means of thermal analysis within

section 10 of this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 20 of 93

6.1.1.6. Locate Significant Heat Sources Away From Fuel Tanks

On most, (but not all), aeroplanes the main heat sources are the environmental

control system packs and the associated pneumatic ducts, normally situated

beneath the centre wing tank. The packs can not be removed from the

aeroplane, as they are essential for flight, to provide pressurised air for

heating/cooling and pressurisation of the cabin/fuselage/equipment.

For those aeroplanes with environmental control system packs and the

associated pneumatic ducts situated beneath the centre wing tank their

relocation is impractical. This is due to the utilisation and optimisation of all

available space on an aeroplane. The relocation of such large components

would disrupt many other aeroplane components and systems.

Thermal analysis predicts the exposure of a Small generic centre wing tank

without adjacent heat sources to be 1%.

For existing aeroplanes this option is not considered further within this report,

due to;

(a) the fact that aeroplane design is optimised leaving no practicable

location to reposition the equipment

(b) that if the necessary space was available the estimated significant

costs of redesign, certification and retrofit are prohibitive.

(c) a comparison to other options discussed in this report

New aeroplane designs could locate the environmental control system packs

away from the fuel tanks. However this would have a very significant effect

becoming a principle driver in the overall configuration and design of the

aeroplane, (due to the significant mass and volume environmental control

systems occupy.

The benefits of this approach are considered further by means of thermal

analysis within section 11 of this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 21 of 93

6.1.2. Active Cooling

6.1.2.1. Cool the Fuel During Refuelling

Loading cooled fuel is already proposed for very small business aeroplanes. This

is done not as a method of reducing fuel tank flammability, but as a means of

increasing range by enabling the uplift of additional fuel mass. The exposure of

empty fuel tanks is not significantly affected.

If such a measure was required for all commercial flights, (as a means of

reducing the exposure of fuel tanks to flammable vapours), it would necessitate a

massive capital investment at all the world’s airports, to purchase and install

cooling equipment. The cooling equipment would need to cool the fuel very fast

to prevent impacting on the aeroplane dispatch time, and thus would be

physically large. For airports having fuel hydrant systems then the cooling

equipment could be stored underground. However for airports using fuelling

trucks then the cooling equipment would need to be towed on a trailer which

would increase further the congestion around the aeroplane.

Additionally cooling would increase the operational costs associated with uplifting

fuel:

• It requires approximately 45kJ to cool 1kg of JETA from 40°C to 20°C, (104°F to 68°F).

• A medium size aircraft flying a medium length mission requires 25,000kg of fuel and therefore an

energy requirement of 1,125,000kJ.

Present certification regulations require that each fuel tank must have an expansion space not less than 2%

of the tank capacity. The loading of fuel cooler than the ambient air temperature would result in either;

(i) A restriction on the maximum fuel volume that could be uplifted.

(ii) A time limitation between refuelling and take-off which if exceeded

due to airport constraints, would require defuelling of the aeroplane.

These are due to the fact that the fuel will heat up inside the fuel tank and thus

expand with the potential of a fuel spillage onto the ground, which would

represent a very real fire hazard.

Due to;

(a) This option would not be effective for empty fuel tanks.

(b) The significant capital investment which would be required at all

airports.

(c) The estimation that a significant increase in operational costs

related to cooling would be incurred with (present technology).

(d) The significant limitations that this option could impose on

aeroplane operation.

(e) A comparison to other options discussed in this report.

this option is not considered further within this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 22 of 93

6.1.2.2. Cool the Fuel in the Fuel Tanks

The cooling of fuel tanks, together with the contained fuel, would require a very

significant cooling capability, which is currently not available from any existing

aeroplane system. Further the ability to use ground equipment to cool the tank

would require the introduction of a new dedicated aeroplane subsystem and a

massive investment in ground equipment. This, in turn, would lead to further

ramp congestion and be detrimental to the environment. It would also introduce,

under failure conditions, the possibility of fuel being dumped overboard due to

expansion.

Due to;

(a) the impracticalities of providing the necessary energy to cool the

fuel

(b) the estimation that a significant increase in operational costs

related to cooling would be incurred

(c) a comparison to other options discussed in this report

this option is not considered further within this report.

6.1.2.3. Cool the Heat Sources Adjacent to Fuel Tanks

The main heat sources on most aeroplanes are the environmental control

system packs and the associated pneumatic ducts situated beneath the centre

wing tank. Under high ambient temperatures, when the necessity to cool these

sources would be greatest, the packs would be working hardest and running

hottest. Thus maximum heat rejection from the packs/ducts would coincide with

the requirement for maximum cooling of the heat sources.

Due to;

(a) the impracticalities of providing the necessary energy to cool

(b) a comparison to other options discussed in this report

this option is not considered further within this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 23 of 93

6.1.3. Controlling Pressure

6.1.3.1. Pressurise the Fuel Tanks

The aim of this measure is to increase the flammability lean limit temperature by

increasing the pressure, with respect to the ambient pressure, within fuel tanks.

Examples of the possible increase in the flammability lean limit temperature that

could be obtained if a fuel tank is pressurised to 200 mb above the ambient

pressure are approximately; 5°C (from 37°C to 42°C) at 6,000ft; 12°C (from 10°C

To pressurise fuel tanks to 200mb would require;

a) a pressurisation system.

b) an over-pressurisation protection system.

c) structural reinforcement.

The majority of present aeroplanes have structural limitations restricting the

pressurisation of fuel tanks to approximately +/- 35 mb. (Aeroplanes with

pressurised fuel tanks do exist today but this is mainly small business jets and

the pressurisation constituted part of the initial design).

Due to;

(a) requirements for large structural reinforcements

(b) new hazards such a system would introduce

(c) a comparison to other options discussed in this report

this option is not considered further within this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 24 of 93

6.2. Eliminating the Ullage

The elimination of the ullage removes the flammable fuel vapour air mixture and

thus significantly reduces the potential of ignition within a fuel tank.

6.2.1. Actively Minimise the Ullage space

The aim of this measure is to minimise the ullage so that there is virtually no

space for fuel vapours. This principle is used in some ground storage tanks.

The two principle means considered are:

(i) To cover the fuel surface with a sheet of impermeable material.

(ii) To fill the ullage space with an inflatable bag.

The main problem with both approaches is that, (unlike ground storage tanks),

there is considerable structure within aeroplane fuel tanks. This structure causes

the fuel surface to change shape as fuel is used. These changes in shape are

such that it is not practicable to use a semi-rigid sheet or inflatable bag due to

the snagging of structure. The use of a large number of low density impermeable

“balls” would overcome the problems of snagging. However this solution would

have problems of ensuring the tank vent system does not become blocked and

that the “balls” do not become heaped in one corner. The heaping of balls in one

corner would allow fuel vapour to fill the ullage space. (The above issues would

be compounded further on aeroplanes where fuel transfers between tanks

occur).

(Some military aeroplanes use collapsible fuel tanks. These eliminate the ullage

by collapsing as fuel is used. Installing such devices into commercial transport

aeroplanes is not practicable for similar reasons as filing the ullage space with

inflatable bags).

This option is considered impractical and is not considered further within

this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 25 of 93

6.2.2. Remove Residual Fuel from Unused Fuel Tanks

The aim of this measure is that by removing all residual fuel you eliminate fuel

vapours.

Aeroplane maintenance manuals specify that several days are required to clean

and vent fuel tanks to eliminate fuel vapours. It is therefore considered

impracticable to perform this task on aeroplane operations where tanks are

nominally empty only intermittently.

However, for a limited number of aeroplane operations where fuel tanks are

never (or extremely infrequently) used conversion from a fuel tank to a dry bay

may be possible. Though preventing fuel vapours from other tanks being drawn

into the “tank” during descent is a significant issue that would need to be solved.

The actual conversion would require measures that, not only prevent the “tank”

from being fuelled, but also prevent fuel leaks and/or provide means of detection

of fuel leakage into the “tank”. Maintenance procedures would also have to be

put in place to prevent any seal within the “tank” drying out. This is to prevent

heavy maintenance action if the tank was to be reactivated.

For most aeroplane operations the only tank which is frequently left empty is the

centre wing tank.

This measure is only practicable for fuel tanks that are intermittently if ever

used. To analyse the economic impact of such a modification it would be

necessary for each individual airline to analyse it’s operations.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 26 of 93

6.3. Sweeping the Ullage

Sweeping the ullage is a method of purging the fuel vapours from the ullage

space in a fuel tank with ambient air. The aim of this process is to reduce the

concentration of fuel vapours to below the lower flammability limit.

6.3.1. Sweeping the Ullage of Empty Fuel Tanks

Laboratory testing of this concept has shown significant fuel evaporation.

Therefore, the evaluation of this method has specifically considered only empty

tanks (defined as containing only unusable fuel).

The source of air would be different for ground and flight and would depend on

the specific aeroplane design. The source of air on the ground could either be a

fan (on the aeroplane or on ground equipment), or the source could be

pressurised air bottles. The source of air in flight could be a ram air inlet, or

modifications to the vent system. To be effective, the air would have to be

correctly distributed within the bays of the tank to prevent direct through flow

which could leave flammable ullage. The swept air, containing fuel vapour, could

exit the tank via the existing vent system.

To minimise the exposure, both a ground and flight system would be required.

Fuel that is lost through evaporation, could be condensed out in a heat

exchanger and drained into a main wing tank minimising the environmental

impact and waste of fuel. Testing has been conducted on a laboratory scale to

evaluate this concept. Details of the testing are described in the appendix

section 15.3.

The benefits of this approach have been the subject of specific testing and

are considered further within section 12 of this report.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 27 of 93

7. METHODS SELECTED FOR FURTHER EVALUATION

7.1. Insulate Heat Sources Adjacent to Fuel Tanks

The evaluation of this method has specifically considered the installation of

insulation blankets around environmental control system pneumatic ducts under

centre wing tanks. This evaluation was performed for the large generic

aeroplane only. The results are therefore not directly applicable to any specific

design.

7.2. Ventilate the Space Between Fuel Tanks and Adjacent Heat Sources

The evaluation of this method has specifically considered forced ventilation

directed into the area between the environmental control system packs and the

lower surface of the centre wing tanks on the ground and in flight. This

evaluation was performed for the medium generic aeroplane only. The results

are therefore not directly applicable to any specific design.

7.3. Redistribute Mission Fuel into Fuel Tanks Adjacent to Heat Sources

The evaluation of this method has specifically considered a change to the

fuelling procedures to re-distribute a portion of mission fuel from the main wing

tanks to the centre wing tank. The fuel in the centre wing tank would then be

used during the initial stages of flight as part of the mission fuel. This evaluation

was performed for the large generic aeroplane only. The results are therefore

not directly applicable to any specific design and the potential impact on the

fatigue life of the aeroplane has not been included in the assessment.

7.4. Locate Significant Heat Sources Away From Fuel Tanks

This method is only applicable for new designs of aeroplanes.

7.5. Sweeping the Ullage of Empty Fuel Tanks

The evaluation of this method has specifically considered an aeroplane system

using a fan to supply air on the ground and a ram air inlet in flight.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 28 of 93

8. INSULATE HEAT SOURCES ADJACENT TO FUEL TANKS

8.1. Safety Impact

8.1.1. Effectiveness in minimising the hazard

This method is effective in reducing the exposure of centre wing tanks to

flammable vapour by limiting the heating effects of environmental control system

packs, but does not eliminate the exposure. This conclusion is supported by

thermal analysis of the large and small generic aeroplanes with environmental

control system packs beneath the centre wing tank and insulation blankets on

the pneumatic ducts in the air-conditioning pack bay. Analysis for these generic

aeroplanes predicts the fleet average exposures to be reduced from 27% to 19%

for the large aeroplane.

8.1.2. Negative impacts

Specific studies of the affect on insulated equipment would need to be

performed for each aeroplane model. This is necessary to ensure that there are

no detrimental effects on the related system. To date there have been no

negative impacts on safety identified.

8.2. Certification Impact

This method would have minimal certification impact using already approved

insulation materials, but may require additional certification for new optimised

insulation materials.

8.2. Environmental Impact

No additional environmental impact identified.

8.4. Aeroplane Impact

• Increased weight.

• Some aeroplanes may require system modifications to compensate for

adverse effects.

• A new dedicated leak detection system may be required due to

reduced accessibility.

• Insulation may not be possible in some confined spaces.

8.5. Operational Impact

• Increased maintenance of the environmental control system or other

effected systems.

• Insulation could result in a reduction in the reliability of some

environmental control system components due to increased running

temperatures.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 29 of 93

8.6. Cost Impact

The following estimated costs are for modifying existing aeroplane designs:

Reason for costs Estimated cost Conversion to $ Cost $

Evaluation and Design 750 man hrs 1 man hour = $85 $63,750

Flight Tests Required

to Verify System effects

10 flight test hrs 1 flight test hour =

$100,000

$1,000,000

Development Costs per Aeroplane Design $1,063,750

Hardware, (insulation

material and fixings)

$4,000 $1 = $1 $4,000

Installation Time 8 man hrs 1 man hour = $60 $480

Installation Costs per Production Aeroplane $4,480

Hardware, (insulation

material and fixings)

$4,000 $1 = $1 $4,000

Installation Time 80 man hrs 1 man hour = $60 $4,800

Lost Revenue due to

down time 2 days

1 day = $6,700 S

1 day = $15,350 M

1 day = $26,800 L

$13,400

$30,700

$53,600

Small

Retrofit Costs per In-Service Aeroplane Medium

Large

$22,200

$39,500

$62,400

Additional Weight of

Hardware 30lbs

1lb = $9,35 S

1lb = $14,10 M

1lb = $9, 55 L

$281

$423

$287

Additional Maintenance 20 man hrs 1man hour = $60 $1,200

Additional Aeroplane Operational Costs Small

per Aeroplane per year Medium

Large

$1,481

$1,623

$1,487

Total Fleet Costs to Insulate Heat Sources Adjacent to Fuel Tanks

Small Medium Large

N° aeroplanes affected 6203 1091 1350

N° models affected 17 9 12

New production per year 200 50 100

Design (1 off) $18,083,750 $9,573,750 $12,765,000

Retrofit costs (1 off) $137,706,600 $43,094,500 $84,240,000

Total one time costs $155,790,350 $52,668,250 $97,005,000

Production (per year) $896,000 $224,000 $448,000

Operation (per year) $9,186,643 $1,770,693 $2,007,450

Total annual costs $10,082,643 $1,994,693 $2,455,450
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 30 of 93

9. VENTILATE THE SPACE BETWEEN FUEL TANKS AND ADJACENT

HEAT SOURCES

9.1. Safety Impact

9.1.1. Effectiveness of minimising the hazard

This method is effective in minimising the exposure of centre wing tanks to

flammable vapour by limiting the heating effects of environmental control system

packs, but does not eliminate the exposure. This conclusion is supported by

thermal analysis of the medium generic aeroplane with centre wing tank with

environmental control system packs beneath the centre wing tank, with forced

ventilation directed to the area between the environmental control system packs

and the lower surface of the with centre wing tank. Analysis for these generic

aeroplanes predicts the fleet average exposures to be 4% for the medium

aeroplane.

9.1.2. Negative impacts

There have been no negative impacts on safety identified.

9.2. Certification Impact

There is flight experience with this type of system on current aeroplanes.

Specific aeroplane designs would have to be certified with some minimal ground

and flight-testing.

9.3. Environmental Impact

No additional environmental impact identified.

9.4. Aeroplane Impact

• Increased weight

• Performance drag penalty

• Effective ventilation may not be possible in some confined spaces

9.5. Operational Impact

• Increased maintenance of new system
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 31 of 93

9.6. Cost Impact

The following costs have been estimated for present aeroplane designs:

Reason for costs Estimated cost Conversion to $ Cost $

Evaluation and Design 10,000 man hrs 1 man hour = $80 $800,000

Flight Tests Required

to Verify System effects

20 flight test hrs 1 flight test hour =

$100,000

$2,000,000

Development Costs per Aeroplane Design $2,800,000

Hardware, (equipment

ducts and fixings)

$20,000 $1 = $1 $20,000

Installation Time 20 man hrs 1 man hour = $60 $1,200

Installation Costs per Production Aeroplane $21,200

Hardware, (insulation

material and fixings)

$20,000 $1 = $1 $20,000

Installation Time 300 man hrs 1 man hour = $60 $18,000

Lost Revenue due to

down time 7 days

1 day = $6,700 S

1 day = $15,350 M

1 day = $26,800 L

$46,900

$107,450

$187,600

Training of Personnel 3 man hrs 1 man hour = $60 $180

Small

Retrofit Costs per In-Service Aeroplane Medium

Large

$85,080

$145,630

$225,780

Operational Delays 8 hrs I hour = $2,875 $23,000

Additional Weight of

Hardware 50lbs

1lb = $9,35 S

1lb = $14,10 M

1lb = $9, 55 L

$468

$705

$478

Additional Maintenance 40 man hrs 1 man hour = $60 $240

Lost Revenue due to

down time 1 day

1 day = $6,700 S

1 day = $15,350 M

1 day = $26,800 L

$6,700

$15,350

$26,800

Additional Aeroplane Operational Costs Small

per Aeroplane per year Medium

Large

$30,408

$39,295

$50,518
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 32 of 93

9.6. Cost Impact (cont.)

Total fleet costs to ventilate the space between fuel tanks and adjacent

heat sources

Small Medium Large

N° aeroplanes

affected

5448 445 1350

N° models affected 14 4 12

New production per

year

200 50 100

Design (1 off) $39,200,000 $11,200,000 $33,600,000

Retrofit costs (1 off) $463,515,840 $43,094,500 $84,240,000

Total one time

costs

$502,715,840 $64,805,350 $304,803,000

Production (per year) $4,240,000 $1,060,000 $2,120,000

Operation (per year) $165,662,784 $17,486,275 $68,199,300

Total annual costs $169,902,784 $18,546,275 $70,319,300
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 33 of 93

10. REDISTRIBUTE MISSION FUEL INTO FUEL TANKS ADJACENT TO

HEAT SOURCES

10.1. Safety Impact

10.1.1. Effectiveness in minimising the hazard

This method is effective in reducing the exposure of centre wing tanks to

flammable vapour by limiting the heating effects of environmental control system

packs, but does not eliminate the exposure. This conclusion is supported by

thermal analysis of the large generic aeroplane with centre wing tanks with

environmental control system packs beneath the centre wing tank. With a

portion of mission the fuel initially loaded into the centre wing tank (10-15% full),

analysis for this generic aeroplane predicts the fleet average exposure to be

reduced from 27% to 20% for the large aeroplane.

10.1.2. Negative impacts

The possibility of fuel system mismanagement could have a negative impact on

safety. There would also be increased crew workload, which for short missions

would occur during already heavy workload periods.

10.2. Certification Impact

There would be some structural analysis required to assess the impact on

structural fatigue and system analysis/flight testing to verify the behaviour of the

aeroplane.

10.3. Environmental Impact

No additional environmental impact identified.

10.4. Aeroplane Impact

• Structural impacts would need to be analysed for each aeroplane

model to verify the impact on the fatigue life of the wing structure

• New procedures would need to be written and approved

• Changes to system warnings and alarms may be required

• Re-programming of fuelling systems may be required

10.5. Operational Impact

• Ground crews and flight crews would have to be retrained on the new

procedures for all operations worldwide.

• Dependant on the optimised fuel mass to be loaded into the centre

wing tank and the resultant structural impact analysis, some

operations may be cargo and/or fuel load restricted. The costs

associated with this payload penalty have been estimated assuming

(a) an optimum fuel load would be approx. 7% of a full tank and (b)

approximately 90% flights are normally operated without fuel in the

centre tank of which 10% would be payload limited.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 34 of 93

10.6. Cost Impact

The following costs have been estimated for applying this procedural

modification to existing aeroplane designs:

Reason for costs Estimated

cost

Conversion to $ Cost $

Evaluation and Design

of Installation

750 man hrs 1 man hour = $80 $60,000

Flight Tests Required to

Verify System effects

2 flight test hrs 1 flight test hour =

$100,000

$200,000

Development Costs per Aeroplane Design $260,000

Training of Personnel 5 man hrs 1 man hour = $60 $300

Lost Revenue due to

Payload Penalty

S 1,500 lbs

M 4,500 lbs

L 12,000 lbs

1lb = $9,35 S

1lb = $14,10 M

1lb = $9, 55 L

$14,025

$63,450

$114,600

Additional Aeroplane Operational Costs Small

per Aeroplane per year Medium

Large

$14,325

$63,750

$114,900

Total fleet costs to redistribute mission fuel into fuel tanks adjacent to

heat sources

Small Medium Large

N° aeroplanes affected 5,448 445 1350

N° flights affected 9.5% 9.0% 8.8%

N° models affected 17 6 12

New production per year 200 50 100

Design (1 off) $4,420,000 $1,560,000 $3,120,000

Total one time costs $4,420,000 $1,560,000 $3,120,000

Operation (per year) $ 7,414,047 $2,553,188 $13,650,120

Total annual costs $ 7,414,047 $2,553,188 $13,650,120
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 35 of 93

11. LOCATE SIGNIFICANT HEAT SOURCES AWAY FROM FUEL TANKS

11.1. Safety Impact

11.1.1. Effectiveness in minimising the hazard

This method is effective in minimising the exposure of centre wing tanks to

flammable vapour by removing the heating effects of environmental control

system packs, but does not eliminate the exposure. This conclusion is supported

by thermal analysis of a small aeroplane without environmental control system

packs beneath the centre wing tank. The fleet average exposure for this generic

aeroplane is estimated to be 1%.

11.1.2. Negative impacts

There have been no negative safety impacts identified.

11.2. Certification Impact

No additional certification work required for new aeroplane designs.

11.3. Environmental Impact

No additional environmental impact identified.

11.4. Aeroplane Impact

Space is a precious commodity on all aircraft. The use of any space is

optimised particularly on the issues of system weight and complexity.

Recent aeroplane designs have been affected by the size of jet engines, the

effect of which has lead to designs with wing mounted engines. On such

aeroplanes it has been shown that the optimised location for environmental

control system packs is beneath the centre wing tank. Relocation of the

environmental control system packs would be a significant driver for the total

aeroplane configuration as well as increasing the weight and complexity of the

systems. Quantifying the impact of this method would only be possible for

specific new designs.

11.5. Operational Impact

The operation of the aircraft could be impacted by the location of the ground

service ports, (dependent on the specific designs).
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 36 of 93

11.6. Cost Impact

The following costs have been estimated for applying this requirement to New

aeroplane designs:

Reason for costs Estimated cost Conversion to $ Cost $

Reconfiguration of

Aeroplane

50,000 man hrs 1 man hour = $80 $4,000,000

Flight Tests Required

to Verify System effects

100 flight test hrs 1 flight test hour =

$100,000

$10,000,000

Development Costs per Aeroplane Design $14,000,000

Hardware, (additional

material and fixings)

$ ? $1 = $2,875 $ ?

Installation Costs per Production Aeroplane $ ?

 

Additional Weight of

Hardware ? lbs

1lb = $9,35 S

1lb = $14,10 M

1lb = $9, 55 L

$ ?

$ ?

$ ?

Additional Aeroplane Operational Costs Small

per Aeroplane per year Medium

Large

$?

$?

$?

Total fleet costs to locate significant heat sources away from fuel tanks

Small Medium Large

N° models affected 2 1 1

New production per year 50 50 50

Design (1 off) $28,000,000 $14,000,000 $14,000,000

Total one time costs $155,790,350 $52,668,250 $97,005,000

Production (per year) $ ? $ ? $ ?

Operation (per year) $ ? $ ? $ ?

Total annual costs $ ? $ ? $ ?
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 37 of 93

12.SWEEP THE ULLAGE OF EMPTY FUEL TANKS

12.1. Safety Impact

12.1.1. Effectiveness of minimising the hazard

Quantifying the reduction in exposure that could be achieved in an actual

aeroplane environment will require further testing and analyses.

12.1.2. Negative impacts

By introducing a new system into the fuel system, there are increased risks of

failure conditions. One such risk is over-pressurisation of the fuel tanks if

fuelling and sweeping occur at the same time. A second risk is the loss of

mission fuel if sweeping occurs in a non-empty tank, due to evaporation.

12.2. Certification Impact

This method would require further laboratory, and aeroplane testing, (both

ground and flight), and would require complete system certification. Proving the

tank to be in a non-flammable condition requires vapour sampling

instrumentation, for which speciality equipment is available for laboratory use,

but no such equipment is available for aeroplane installations.

12.3. Environmental Impact

Sweeping the ullage would increase fuel vapour emissions out of the fuel tank. A

system could be designed to collect the fuel vapour, but would add system

complexity.

12.4. Aeroplane Impact

• There would be additional weight of an air distribution system in the

fuel tank.

• There may also be additional weight if a fuel vapour collection system

is required.

• The addition of a new sweeping system would require additional fire

protection systems.

12.5. Operational Impact

• A source of air would be required, both on the ground and in flight. A

ground system could increase ground time and involve ground crew

training. A flight system would incur a drag penalty to the aircraft

performance.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 38 of 93

12.6. Cost Impact

The following costs have been estimated for applying this modification to

existing aeroplane designs:

Reason for costs Estimated

cost

Conversion to $ Cost $

Evaluation and Design 20,000 man hrs 1 man hour = $80 $1,600,000

Flight Tests Required

to Verify System effect

100 flight test

hrs

1 flight test hour =

$100,000

$10,000,000

Development Costs per Aeroplane Design $11,600,000

Hardware, (equipment,

pipe-work and fixings)

$60,000 $1 = $1 $60,000

Installation Time 50 man hrs 1man hour = $60 $3,000

Installation Costs per Production Aeroplane $63,000

Hardware, (equipment,

pipe-work and fixings)

$60,000 $1 = $1 $60,000

Installation Time 1,000 man hrs 1 man hour = $60 $60,000

Lost Revenue due to

down time 25 days

1 day = $6,700 S

1 day = $15,350 M

1 day = $26,800 L

$167,500

$383,750

$670,000

One Time Training of

Personnel

3 man hrs 1 man hour = $60 $180

Small

Retrofit Costs per In-Service Aeroplane Medium

Large

$287,680

$503,930

$790,180

Operational Delays 16 hrs I hour = $2,875 $46,000

Additional Weight of

Hardware 70lbs

1lb = $9.35 S

1lb = $14.10 M

1lb = $9.55 L

$655

$987

$669

Additional

Maintenance

60 man hrs 1 man hour = $60 $3,600

Lost Revenue due to

down time 1 day

1 day = $6,700 S

1 day = $15,350 M

1 day = $26,800 L

$6,700

$15,350

$26,800

Additional Aeroplane Operational Costs Small

per Aeroplane per year Medium

Large

$56,955

$65,937

$77,069
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 39 of 93

12.6. Cost Impact (cont.)

Total fleet costs to sweep the ullage of empty fuel tanks

Small Medium Large

N° aeroplanes affected 6203 1091 1350

N° models affected 17 9 12

New production per year 200 50 100

Design (1 off) $197,200,000 $104,400,000 $139,200,000

Retrofit costs (1 off) $1,784,479,040 $549,787,630 $1,066,743,000

Total one time costs $1,981,679,040 $654,187,630 $1,205,943,000

Production (per year) $12,600,000 $3,150,000 $6,300,000

Operation (per year) $353,291,865 $71,937,267 $175,980,417

Total annual costs $365,891,865 $75,087,267 $182,280,417
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 40 of 93

13.CONCLUSIONS

Thermal analysis has shown that all generic fuel tank designs have some

exposure to flammable fuel vapour.

• Tanks without adjacent heat sources, independent of their location in

the aeroplane, (wing or fuselage), have equivalent exposure of

approximately 5%.

• Tanks that have adjacent heat sources have exposure of

approximately 30%.

Thirteen options have been considered. Only one eliminates exposure to fuel

vapours. This is achieved by disabling the fuel tank and thus has severe

operational consequences that can only be evaluated for individual airlines

operations, and thus no conclusion is provided within this report.

Five of the methods considered reduce the exposure to flammable fuel vapour,

and have been evaluated for the Small, Medium and Large transport

Aeroplanes:

1. Insulate the heat source adjacent to fuel tanks

2. Ventilate the space between fuel tanks and adjacent heat sources

3. Redistribute mission fuel into fuel tanks adjacent to heat sources

4. Locate significant heat sources away from fuel tanks.

5. Sweep the ullage of empty fuel tanks

Options 2 and 4 have been shown to reduce the exposure of fuel tanks with

adjacent heat sources to a level similar to fuel tanks without adjacent heat

sources. (Option 4 is only applicable to new aeroplane designs).

Option 5 requires significant further research before a conclusion on its

feasibility can be reached. (Table 13.1 summarises the effects and impact of the

five options).

In addition the effects of ground inerting and changing the fuel flashpoint

specification have been assessed. Either of these methods could reduce the

exposure of fuel tanks with adjacent heat sources to a level similar to fuel tanks

without adjacent heat sources. (Table 13.2 summarises the effects on exposure

of ground inerting, changing the flashpoint, and some potential combinations of

modifications (that could be evaluated in the timeframe available).
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 41 of 93

Table 13.1 Summary of impacts and applicability of the five methods evaluated

Centre Wing Tanks With Adjacent Heat Sources

Exposure to Flammable Vapours 30%

Fuel Tanks Without Adjacent Heat Sources

Exposure to Flammable Vapours 5 %

OPTION

IMPACT

1.

Insulate

2.

Ventilate

3.

Redistribute

4.

Locate

5.

Sweep

Estimated Exposure to

Flammable Vapours

after Modification

20% 5% 20% 5%

Not

quantified

New safety Concerns minor none Medium none Medium

Certification Impact minor minor minor none MAJOR

Environmental Impact none none none none YES

Aeroplane Impact minor Medium minor MAJOR Medium

Operational Impact minor minor MAJOR minor MAJOR

One Time Small

Fleet Costs Medium

($ x 106

) Large

160

50

100

500

60

300

4

2

3

160

50

100

2,000

650

1,200

Annual Fleet Small

Costs Medium

($ x 106

) Large

10

2

2

170

20

70

7

3

14

?

?

?

370

80

180

Applicability MOST MOST MOST NEW

DESIGNS

MOST

Table 13.2 Summary of the effects of changing the fuel flashpoint, ground

inerting and combinations of different modifications.

Modification

Wing Tanks

Without heat

sources

Centre Tanks

without heat

sources

Centre Tanks

with heat

sources

Current Aeroplanes 5% 5% 30%

120°F Flashpoint Fuel

130°F Flashpoint Fuel

140°F Flashpoint Fuel

150°F Flashpoint Fuel

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

< 1%

10 to 20%

5 to 10%

1 to 5%

1%

Ground Based Inerting

of Fuel Tanks

Not applicable < 1% 1%

Combinations of

Modifications

Ventilate and 120°F Not applicable Not applicable < 1%

Insulate and 120°F Not applicable Not applicable 5%

Insulate and 130°F Not applicable Not applicable 1%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 42 of 93

14.REFERENCES

Boeing Document, D6-52754, “Handbook of Properties of Common Petroleum

Fuels,” John E. Schmidt, Dec. 1984, Boeing Commercial Airplane Group,

Seattle, WA.

Handbook of Aviation Fuel Properties

(Co-ordinating Research Council, Inc)
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 43 of 93

15. APPENDIX

15.1 Thermal Model Descriptions

15.1.1 Centre Wing Tank (Large Aeroplane)

A thermal model was developed and correlated for a large aeroplane centre fuel

tank. It predicts liquid & ullage temperatures on the ground and during flight for

various ambient and operational conditions. Operational conditions include tank

fuel volumes, aeroplane pitch, environmental control system pack component

temperatures, and mission length. The model also assesses the effect of

aeroplane structural and operational changes on fuel and ullage temperature

profiles for a range of ambient temperature profiles. The model can handle the

following changes:

1. Environmental control system pack surfaces with and without insulation.

2. Environmental control system pack ventilation

3. Varying fuel volumes in tanks

4. Varying aeroplane attitude

The model evaluates the effect of the following operational and design

modifications on centre wing tank, fuel and ullage temperatures for 3 mission

lengths and 7 ambient air temperature profiles:

1. Existing aeroplane configuration

2. Ventilating the environmental control system pack bay with ambient air

3. Insulating the environmental control system pack bay ducts.

The model is transient and includes the following elements and influences:

1. centre wing tank

2. inboard wing tanks

3. wing structure

4. body structure

5. air conditioning (a/c) packs

6. heat transfer to and from ambient

Analytical Tools

Computer modelling was performed using the SINDA85 / FLUINT thermal/fluid

analysis program. This program is an industry standard finite difference code,

designed to handle lumped parameter thermal/fluid systems that include

radiation, convection, and conduction heat transfer and single, or two-phase,

fluid flow.

The overall model was created using three sub-models for fluid flow and one

sub-model for thermal transfer. The fluid sub-models analyse air movement

between the inboard wing tank and ambient, centre wing tanks and ambient, and
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 44 of 93

between the pack bay and ambient through drainage holes in the environmental

control system pack bay fairing.

The thermal sub-model analyses the conduction and radiation heat transfer

within and between the centre wing tank, environmental control system packs

and bay, and the inboard wing tanks. This high level of detail is driven by the

need to identify the relative influence of a large number of variables on tank fuel

temperatures.

Inboard Wing Tank

The inboard wing tank was included in the thermal/fluid model in order to provide

a centre tank side boundary temperature. It consists of a six-sided box, as

shown in figure 15.1.1.1, below. In order to capture temperature differences

between surfaces in contact with the ullage and liquid each tank surface has two

nodes corresponding to the surface areas in contact with ullage and liquid.

Figure 15.1.1.1

Depending on the volume of fuel in the tank and the aeroplane pitch and roll,

each side of the box may be in contact with liquid or vapour, or both liquid and

vapour. For example, on the ground before takeoff the lower and inboard

surfaces are typically completely covered with liquid while the remaining

surfaces are in contact with both liquid and ullage. During flight as fuel is

withdrawn from the tank the program automatically changes the fuel and tank

node thermal capacitance and conductor values to account for the new wetted

contact areas. If a surface becomes completely dry during a mission then the

corresponding liquid node is mathematically isolated from the model.

Tank internal heat transfer includes free convection between the tank surfaces

and the liquid and ullage, and between the liquid surface and ullage and

913 / 923

914 / 924

911 - 916 qulidicontact

921 - 926 ullage contact

901 liquid

902 ullage

997

998

747inbd

2/23/98
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 45 of 93

radiation from the liquid to the upper wing surface not in contact with the liquid.

A discussion of the heat transfer calculation occurs later in this write up. Internal

radiation is only analysed between the liquid surface and the upper tank (wing)

surface.

Tank external heat transfer includes forced convection to a total air temperature

node, radiation to sky and/or ground temperature nodes and a solar load on the

upper wing surface.

The ullage is modelled in the fluid sub-model as a single air node connected to

ambient, which allows airflow into and out of the tank through the tank vent

system as the aeroplane altitude changes. The liquid is modelled in the thermal

sub-model as a single thermal node.

Center Wing Tank

The centre tank model consists of a thermal sub-model, and ullage and

environmental control system pack air fluid sub-models.

The centre wing tank thermal sub-model includes the tank bottom & top,

spanwise beams, front & rear spars, environmental control system pack

components and, environmental control system pack bay fairing. Nodal density

is greatest on the tank bottom surfaces, with 140 nodes, since these surfaces

have the greatest effect on fuel temperatures, and temperature gradients are

large due to uneven heating from the environmental control system packs

located directly below. The node density on the remaining surfaces is less in

order to minimise model run times. Nodal maps for the thermal sub-models are

provided in figures 15.1.1.2 through 15.1.1.4.

The tank ullage fluid sub-model simulates ullage movement between the tank

compartments and through the tank venting ducts to ambient. The environmental

control system pack bay fluid sub-model models pack leakage into the

environmental control system pack bay, airflow between the environmental

control system pack bay and the adjacent dry bay, and ambient air leakage into

and out of the pack bay through drainage holes in the pack bay fairing.

The tank bottom was divided into the 7 by 20 node grid. Unlike the inboard wing

tank model the centre tank model assumes each node is in contact with either

the liquid or ullage. FORTRAN control logic ensures that radiation and free

convection occurs from either the liquid or tank surface for each tank bottom

surface node depending on the fuel location through out the mission.

The frequency of nodes along the axis of the aeroplane is greater in order to

capture the effect of fuel movement within the tank caused by changes in

aeroplane pitch. Because the slope of the tank bottom is so gradual small

variations in aeroplane pitch can have a large effect on the location of the fuel

within the tank and more important, the total contact area between the fuel and
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 46 of 93

tank bottom. As the contact area increases total heat transfer to the fuel

increases since the convective heat transfer from the fuel to the tank bottom is

larger than the convective heat transfer and radiation from the fuel surface to the

tank ullage and inner surfaces.

The location of the fuel within the tank and the amount of fuel remaining in the

tank also have a large effect on the fuel temperature. This is due to variations in

heat transfer between the environmental control system pack surfaces and the

tank bottom surface. To capture the effect of fuel location on fuel temperature,

the fuel location and total fuel to tank bottom surface contact area is input in the

model array data block. The wetted surface area between the centre wing tank

fuel and tank bottom, tank side and spanwise beams which also varies with

aeroplane pitch and the amount of fuel remaining in the tank is calculated on an

Excel spreadsheet and imported in data arrays.

CWT Thermal Nodal Maps

Figure 15.1.1.2 Centre Wing Tank Bottom Surface Nodes

forward spar

111 112 113 114 115 116 117

121 122 123 124 125 126 127

131 132 133 134 135 136 137

141 142 143 144 145 146 147

211 212 213 214 215 216 217

221 222 223 224 225 226 227

231 232 233 234 235 236 237

241 242 243 244 245 246 247

311 312 313 314 315 316 317

321 322 323 324 325 326 327

331 332 333 334 335 336 337

341 342 343 344 345 346 347

411 412 413 414 415 416 417

421 422 423 424 425 426 427

431 432 433 434 435 436 437

441 442 443 444 445 446 447

511 512 513 514 515 516 517

521 522 523 524 525 526 527

531 532 533 534 535 536 537

541 542 543 544 545 546 547

rear spar
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 47 of 93

Figure 15.1.1.3 Centre Wing Tank Vapour and Vertical Surface Nodes

Figure 15.1.1.4 Fairing Interior and Exterior Nodes

forward spar

2811 2812 2813 2814 2815 2816 2817

3811 3812 3813 3814 3815 3816 3817

2111 2112 2113 2114 2115 2116 2117

3111 3112 3113 3114 3115 3116 3117

2211 2212 2213 2214 2215 2216 2217

3211 3212 3213 3214 3215 3216 3217

2311 2312 2313 2314 2315 2316 2317

3311 3312 3314 3315 3316 3317

2411 2412 2413 2414 2415 2416 2417

3411 3412 3413 3414 3415 3416 3417

2511 2512 2513 2514 2515 2516 2517

3511 3512 3513 3514 3515 3516 3517

2611 2612 2613 2614 2615 2616 2617

3611 3612 3613 3614 3615 3616 3617

2711 2712 2713 2714 2715 2716 2717

3711 3717

rear spar

front

4011

1 4111 4121

4131

4021

2 4112 4122

4132

4031

915 3 4113 4123

4133

4041 4144 4041

4 4114 4124 4

4134

4051 4145 4051

5 4115 4125 5

4135

4061 4061

centre line
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 48 of 93

Radiation Models

The environmental control system pack bay and centre wing tank internal

thermal sub-models include about 900 and 2600 radiation conductors

respectively, (see figure 15.1.1.5). Radiation conductors inside the

environmental control system pack bay and centre wing tank internal tank were

created using Radsim, a Boeing proprietary radiation simulation program.

The environmental control system pack, bleed air, APU and supply air duct are

broken up into 32 surfaces which radiate to the centre wing tank bottom and

pack bay fairing interior surfaces. Each surface is assigned a unique boundary

temperature, which varies during and between missions due to changes in

ambient temperature and predicted pack performance. Environmental control

system pack surface boundary temperatures are based on test data and

predictions from a pack computer model.

Insulated ducts are modelled with an additional insulation outer surface

arithmetic node connected to the duct boundary node through a conduction heat

transfer path.

Figure 15.1.1.5 Environmental Control System Pack Bay Radiation Model
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 49 of 93

Convective Heat Transfer

Convection heat transfer from the exterior surfaces outside the inboard wing

tank and pack bay fairing is modelled using a standard forced convection heat

transfer correlation for flow over a flat plate. The program models convection

heat transfer from the aeroplane exterior surfaces to a boundary ambient total air

temperature node. The total air temperature assumes a 100% temperature

recovery factor. For the ground conditions a 3 mile per hour wind speed is used

in calculating the heat transfer coefficient.

Natural convection heat transfer coefficients are calculated for all model

surfaces not in contact with the aeroplane exterior, which includes tank inner

surfaces and a/c pack components. For natural convection, the heat transfer

correlations are a function of temperature difference between the fluid and

surface, surface orientation, fluid properties and (for horizontal surfaces)

whether the surface is warmer then adjacent fluid. The program chooses the

appropriate correlation, based on the above mentioned information and

continuously updates all natural convection heat transfer coefficients.

Fuel Properties

The program was designed to model various fuels, (JET A, Aviation Gas, JP-4,

JP-5), by setting the fuel type flag. Jet A was used for this study.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 50 of 93

15.1.2 Main Wing Tank (Small and Large Aeroplane)

The wing tank thermal model simulates heat transfer between a fuel system and

its surroundings during an aeroplane flight. This model was designed to predict

in-flight fuel temperatures for (main) integral wing tanks of commercial

aeroplanes using quasi-steady state equations of heat transfer.

A fuel system consists of fuel tanks, plumbing lines and components such as

pumps, valves, pressure switches and the like for fuel management. There may

be several fuel tanks with a provision of fuel transfer between tanks.

The time dependent heat transfer process is influenced by factors including the

environment and the aeroplane flight profile. The initial fuel tank quantity also

changes depending on the engine feed rate and fuel transfers from other tanks.

The principal mechanisms of heat transfer considered in this model are:

• Convective heat transfer from the aerodynamic boundary layer outside the

tank to/from the tank surface

• Conductive heat transfer through the tank wall

• Convective heat transfer from the wetted tank inside wall to/from bulk fuel

• Radiative heat transfer from the fuel surface to the dry areas of tank inside

wall

• Conductive heat transfer through the dry area of tank wall

• Radiative heat loss/gain from the tank outside surfaces to sky or ground

• Solar radiation to the tank surfaces

Assumption

The thermodynamic properties do not change rapidly so that the heat transfer

process can be considered quasi-steady state.

Method of Solution

The generalised mass and energy conservation equations are developed for a

tank. These are applied for a small time increment Δt. At each time step,

recovery temperature for the aerodynamic boundary layer and Reynolds number

at the tank leading edge (for determining the aerodynamic heat transfer

coefficient) are calculated based on the flight profile. Similarly, tank wetted and

dry areas based on fuel quantity remaining are determined. The equations are

solved numerically to obtain the bulk fuel temperature at the end of the time

interval for all the tanks. The process is repeated to cover the entire flight

profile.

Inputs

Inputs required include:

ß Fuel System Details - Number of tanks, fuel volume versus tank wetted area

for each tank, tank material properties
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 51 of 93

ß Atmospheric Data - Altitude versus pressure, air temperature, sky and ground

temperatures

ß Flight Profile - Aeroplane speed and altitude as a function of time

ß Fuel Management Data - Engine feed rate and tank-to-tank fuel transfer

schedules

ß Internal Heat Sources - Heat inputs as a function of time

ß Initial Conditions - Fuel quantity and temperature in each tank, specific

gravity

Output

The main output of the computer program is a history of fuel quantity and

temperature in each tank of the fuel system.

The model described above has evolved over many years. It is highly versatile

in dealing with fuel systems with a large number of tanks and complex fuel

management schemes. It can also predict fuel temperature variation while the

aeroplane is on the ground. The only major is its inability to provide any

information on fuel temperature stratification within tanks. It is well known that

such stratification, principally in the vertical plane, does occur. Fuel is mixed in

flight, but not nearly enough to maintain thermal continuity. However, the model

has not been designed to address this behaviour mainly to avoid complexity and

to keep run times short.

Schematic

The following sketch shows various modes of heat transfer.

In addition to the heat transfer mechanisms listed above, there also is a

provision for heat sources internal to the tank.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 52 of 93

15.1.3 Centre Wing Tank (Small Aeroplane)

Model Assumptions

The wing tank thermal model described in Section 15.1.2 was used as the basis

for the development of a thermal model for centre wing tanks. The centre wing

tank thermal model is simplified from the main tank model by the following

assumptions:

• Aerodynamic heating or cooling of the tank surfaces is not applicable.

• The tank is a basic cube, six flat surfaces without internal structure

(bays).

Both models utilise the following assumptions:

• Steady state equations apply over a short time interval (0.5 minutes).

• Constant heat transfer coefficients and emissivities.

• The surface temperatures of the tank walls are uniform (uniform boundary

conditions).

• Calculated fuel temperature is uniform throughout the fuel layer.

• Calculated ullage temperature is uniform throughout the ullage space.

• Ambient temperature and pressure gradients with altitude are standard

atmosphere.

Boundary Conditions

For the tank wall surface temperatures, the model assumes a constant 70°F for

the top wall (floor of the passenger cabin) and front wall (cargo bay). Over the

flight profile, the sidewalls track the main tank fuel temperature (input from the

wing tank thermal model), and the rear wall (wheel well) tracks total air

temperature. The bottom wall surface temperature is calculated in the model as

the boundary between the environmental control system bay and fuel tank. The

bottom surface of the environmental control system bay tracks total air

temperature.

Initial Conditions

For the initial conditions, the model assumes that the initial fuel, ullage, and

environmental control system bay air temperatures equal the initial ambient

temperature.

Model Inputs

The inputs to the program by the user are:

• Dimensions and volumes of the centre wing tank and environmental

control system bay for the specific model aeroplane

• Flight profile - Altitude vs. time, including Mach No., vs. time (used to

calculate total air temperature)

• environmental control system pack surface temperature vs. time

• Fuel temperature of main wing tanks vs. time
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 53 of 93

• Fuel load vs. time, including the area of the bottom surface wetted by the

fuel (for small quantities only)

• Initial ambient temperature on the ground (default of 60°F)

• Initial fuel temperature (default is equal to initial ambient temperature)

• The type of fuel in the tank (specifically the flash point)

• Addition of a layer of insulation, with specified thermal conductivity and

thickness, onto the bottom of the tank to study the thermal effects.

Model Output

The output of the thermal model is the predicted fuel, ullage, and environmental

control system bay air temperatures over time.

Model Validation

The model has been validated with average fuel, ullage, and environmental

control system bay air temperatures measured in ground and flight tests on a

large aeroplane. The model does not always track the data exactly, but always

predicts the trends accurately. Therefore, this simple model used in this study

provides adequately accurate results to compare the effect of several options.

Center Wing Tank Thermal Model

Passenger Cabin

70oF / 21oC

Total Temp.

Fuel Temp

Model Output

ECS Bay Air Temp

Model Ouput

Ullage Temp

Model Output

Wheel Well

Tracks Total Temp.

Main Fuel Tank

Model Input

Cargo Bay

70oF / 21oC

Main Fuel Tank

Model Input

Forward

Up
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 54 of 93

15.1.4 Main Wing Tank (Medium Aeroplane)

A fuel wing tank model was created within British Aerospace to study the

evolution of fuel temperatures during flight for both subsonic and supersonic

flight. This model is presently inactive but results for a medium aeroplane both

inner and outer tanks are shown in 15.2.4.

Though the model has not been used to calculate a total fleet wide exposure

figure it has been used to estimate that Medium aeroplanes do not have an

exposure to flammable fuel vapours significantly different to Small are Large

aeroplanes.

The model calculated skin and the bulk mean fuel temperature by solving the

steady state heat transfer equations for consecutive short time intervals. The

results were validated against flight test and found to be within +/- 2°C.

The model considers three variables; flight profile, ground fuel temperature and

ambient air temperature. The results shown in 15.2.4 use; four different flight

profiles, two ground fuel temperatures and two ambient air temperatures. By use

of data shown in 15.2.4 figure 7 it is possible to correct the data for other

ambient air temperatures.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 55 of 93

15.1.5 Centre Wing Tank (Medium Aeroplane)

A thermal model has been developed for a centre wing tank of generic medium

size aeroplane, with directed ventilation of the space beneath the tank and a

vapour seal. The model determines the temperature of fuel and ullage within the

centre wing tank and the air in the compartments adjacent to the centre wing

tank.

The model uses basic thermodynamic principles, in particular heat transfer by;

• convection

• conduction

• radiation

The relevant aeroplane compartments considered are;

• the environmental control system pack bay beneath the centre wing

tank

• the vapour seal directly beneath the centre wing tank

• the fuel volume within the centre wing tank

• the ullage within the centre wing tank

and are shown in figure 15.1.5.1.

For each compartment a differential thermal balance equation has been

established considering a global heat transfer of the fluid, (air, fuel and ullage),

within the compartment, with the relevant surfaces in contact with the fluid.

Four thermal differential equations have been used to determine the required

temperature variations during aircraft operations. These equations are resolved

by use of a MATLAB software programme.

The programme takes into account the fuel consumption and hence the variation

in fuel mass and level, within the centre tank during flight. Flight test data has

been used to provide the temperatures of the fuel masses in the left and right

wings.

The various convection coefficients of air and ullage have been corrected for

changes in aeroplane altitude.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 56 of 93

Figure 15.1.5.1 Aeroplane Compartments Considered
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 57 of 93

15.1.6 Main Wing Tank (Business Jet and Regional Turbofan)

A Thermal/Fluid fuel tank model was created to evaluate the effects of a Heated

Fuel Return System (HFRS) in a bizjet wing fuel tank, (the same model was

adapted to asses a generic regional turbofan). It was developed using a

transient Thermal analysis program. This technique utilises the finite difference

method and applies a forward time stepping approach to solve a matrix of nonlinear simultaneous equations. The model is made up of a number of lumped

parameters (nodes) that represent selected masses associated with the physical

problem.

The program is capable of addressing conduction, convection and radiation heat

transfer as well as heat sources and sinks. Subroutines are provided internally

that enable the user to code detailed physical logic into the analytical model.

Because of the fluid nature of the HFRS, major innovations were made in the

Thermal technique in order to model in detail, the predicted fuel flows/levels

throughout the tank. This has the effect of modifying both the fuel node masses

and dimensions with time.

The Thermal network also utilises this embedded Fluid nodal model to account

for the heat flux resulting from the liquid mass transfer. Each Thermal fuel node

has an associated Fluid conductor. The model is made up of:

ß 57 iterated nodes (to be solved for),

ß 24 zero capacitance nodes (air nodes, to limit calculation time),

ß 245 boundary nodes (used for boundary conditions, input ports or fluid links),

ß 376 thermal and fluid conduction links,

ß one internal heat source

ß Eight external solar inputs.

The model is divided into an external reheated fuel segment and eight internal

regions representing partitioned wing bays #0 through #6 and the inboard

located hopper. The internal segments are connected in a series loop via fluid

conductors with an internal parallel link existing between the hopper and bay #0

to account for its continuous fuel overflow.

Each bay is divided into upper and lower aluminium skins, an internal air node

above the fuel and five fuel nodes. The skins are connected to the ambient

turbulent recovery temperature by a turbulent forced convection coupling. The

fuel nodes are connected internally by conduction and convection couplings and

an additional flow couplings to allow heat to flow, (due to the fuel flow mass

transfer), to connect them.

As fuel is depleted, the nodes reduce in size (height/mass) from the uppermost

one, and collapse onto each other and eventually down to the lower skin. The

bays are connected to each other only by flow couplings (i.e., no conduction
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 58 of 93

through the ribs which is insignificant). The model utilises fuel loading/burn data

in tabular form to define the amount of fuel present in any bay at any instant.

The internal convective fluid heat transfer coefficients were modified based on

data obtained from two flight tests (they essentially represent the mixing caused

by vibration). The first case had the HFRS off and the second had the HFRS

turned on. The modified coefficients enabled the model to accurately predict the

recorded data with the system both operating and not operating. The model was

then applied to the second flight test with the HFRS "turned" off in the model.

There was a significant difference in the results, indicating that the system was

working as designed and that the model was capable of handling a broad

spectrum of cases.

Based on these empirical/analytical results, additional test instrumentation was

added to the non-heated wing (LH) and an extended flight was conducted. The

results of this test were analysed using the model without further modification

and the results were in good agreement with the data for both wings. As a

result, it has been demonstrated that the Thermal model satisfactorily predicts

the bizjet fuel temperatures and temperature stratification throughout the entire

wing tank.

The model described above was used to predict the Thermal response of the

fuel in the bizjet wing tank for three mission profiles and seven different

temperature atmospheres. The reported results are for the innermost wing tank

section (bay#1) which by virtue of containing the most fuel, cools down the

slowest and results in the most severe exposure condition.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 59 of 93

15.1.7 Centre Wing Tank

(Small Aeroplane without Adjacent Heat Source)

Centre Wing Tank

The centre wing tank is simulated as a basic cube with 6 fuel cells.

The following figure shows the relative position of the centre wing tank.

Analysis Tools

The System Improved Numerical Differencing Analyser (SINDA/G) thermal

modelling system was used to model the centre wing tank. SINDA/G is a

software system for solving lumped parameter representations of physical

problems governed by diffusion-type equations. It is a general thermal analyser

accepting conductor-capacitor (G-C) network representations of thermal

systems.

Forward

Cabin Floor Beam

CWT

Fillet

Cavity
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 60 of 93

A transient model was built to calculate the fuel temperature history inside the

centre wing tank with various flight profiles. Microsoft Excel spreadsheet is used

to calculate the adiabatic wall temperature vs. time.

Model Assumptions

ß The surface temperatures of the tank walls are uniform.

ß Radiation heat transfer is not considered.

ß No heat transferred from fuel to the ullage or from ullage to fuel.

ß Calculated fuel temperature and ullage temperature are uniform throughout

the centre wing tank.

ß Adiabatic wall temperature is used to simulate the air in the wheel well

compartment and in the fillet.

ß Top of the centre wing tank was exposed to the warm air between the floor

beam and the centre wing tank, the heat transfer coefficient from the air to

the top of the centre wing tank wall is constant.

ß Both the left and right side of the centre wing tank walls were exposed to the

fuel in the main fuel tank. Natural convection is assumed for the heat

transfer from these walls to the fuel in the main tank.

ß The Centre Auxiliary Compartment is forward of the centre wing tank, the

heat transfer coefficient from the air in Centre Auxiliary Compartment to the

centre wing tank wall is constant.

ß The wheel well compartment is located aft of the centre wing tank, the fillets

are connected to the wheel well compartment. The heat transfer coefficient

is varied with time in flight depending on Mach number.

ß Underneath the centre wing tank is the cavity. The air temperature in the

cavity is assumed to be the adiabatic wall temperature and the heat transfer

from the cavity to the bottom of the centre wing tank is assumed to natural

convection.

ß Ambient temperature and pressure gradients with altitude are standard

atmosphere.

Boundary Conditions

For the air temperature between the floor beam and the top of the centre wing

tank wall is 75° Fahrenheit. The air temperature in the Centre Auxiliary

Compartment (forward of the centre wing tank) is also 75°F. Over the flight

profile, the side walls tract the main tank fuel temperature (average temperature

of the fuel in the centre wing tank and the main tank in the previous time step).

The air temperature in the wheel well and the tunnels is equal to the adiabatic

wall temperature. The air temperature under the centre wing tank wall is equal to

the air temperature in the wheel well compartment.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 61 of 93

Initial Conditions

The model assumes that the initial fuel, ullage temperatures are equal to the

ambient temperature. Packs are operating on the ground before the flight. The

air temperature in Centre Auxiliary Compartment and between the floor beam

and the centre wing tank top wall is 75°F.

Model Inputs

ß Dimensions and volumes of the centre wing tank.

ß Flight profile - Fuel quantity in centre wing tank vs. time, adiabatic wall

temperature vs. time, heat transfer coefficient vs. time.

ß Initial ambient temperature on the ground.

ß Initial fuel temperature.

ß Centre Auxiliary Compartment air temperature and air temperature under the

floor beam.

Model Output

The outputs of the model are the predicted fuel temperature and tank wall

temperature vs. time.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 62 of 93

15.1.8 Centre Wing Tank (Regional Turbofan)

The mission profiles considered were short and long mission lengths of 400 and

800 nautical miles. These were chosen as the proportion of flights with mission

lengths between 0- 650 N.M is estimated to be 85% (short mission), and mission

lengths between 650-1000 N.M at 15% (long mission).

Flight profiles were based on the delta ISA condition in flight as specified by

Task Group 8 for the altitude range 20,000ft and above. For the altitude range

below 20,000ft an incremental approximation was made starting at the specified

ground delta ISA condition and finishing at specified delta ISA condition at

20,000ft.

The rate of climb is based on actual engine performance for these temperatures.

Ground time is 15 minutes before takeoff and 15 minutes after landing.

Fuel load in the centre wing tank is assumed for both mission lengths. This is

very conservative and only representative for fuel tankering, i.e. flying several

hops without refuelling. Normally the centre wing tank is not filled for mission

lengths below 950 N.M but it may be assumed that 5% of all missions are with

fuel in the centre wing tank to account for tankering. To indicate the effect of an

empty centre wing tank the flight profiles are also given for 400 and 800 nautical

miles for the "extremely hot" condition. For lower ambient temperature

conditions the exposure % is close to zero hence not of interest in this regard.

The fuel temperature always equals the ambient temperature at the start of

flight. The thermal model does not account for the radiation effects because of

the low temperature of air and equipment surrounding the centre wing tank. In

the future, the model may need some refinement to correctly address time

constants of tank structure etc.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 63 of 93

15.2 Thermal Model Predicted Bulk Fuel Temperatures Results Charts

15.2.1 Large Aeroplane Wing Tank

LARGE AEROPLANE WING TANK - LONG MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 100% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

LARGE AEROPLANE WING TANK - MEDIUM MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7 8 9 1 0 1 1

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 100% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

LARGE AEROPLANE W ING TANK - SHORT MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 100% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 64 of 93

15.2.2 Small Aeroplane Wing Tank

SMALL AEROPLANE WING TANK - LONG MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

SMALL AEROPLANE WING TANK - MEDIUM MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 100% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

SMALL AEROPLANE WING TANK - SHORT MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 100% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 65 of 93

 15.2.3 Business Jet Wing Tank

BUS INESS JET - LONG M IS S IO N

-40

-30

-20

-10

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

100

110

120

130

140

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

1 % 25%

50% 75%

95% 99%

99.9% FP = 5%

FP = 25% FP = 50%

FP = 75% FP = 95%

ALTITUTE

BUS INESS JET - MED IUM M ISSION

-40

-30

-20

-10

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

100

110

120

130

140

0 1 2 3 4 5 6 7 8 9

T I ME ( HOURS )

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

1 % 2 5 %

5 0 % 7 5 %

9 5 % 9 9 %

99.9 % FP = 5%

FP = 25% FP = 50%

FP = 75% FP = 95%

ALTITUTE

BUS INESS JET - SHORT MISSION

-40

-30

-20

-10

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

100

110

120

130

140

0 1 2 3 4

T IME ( HOURS )

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

1 % 2 5 %

5 0 % 7 5 %

9 5 % 9 9 %

99.9% FP = 5%

FP = 25% FP = 50%

FP = 75% FP = 95%

ALTITUTE
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 66 of 93

15.2.4 Regional Turbofan Wing Tank

REGIONAL TURBOFAN W ING - TYPICAL M IS S IO N

-40

-30

-20

-10

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

100

110

120

130

140

0 1 2 3

T IME (HOURS )

FUEL TEMPERATURE (°F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT)

COLD 1%

COOL 25%

AVERAGE 50%

WARM 75%

HOT 95%

VERY HOT 99%

EX HOT 99.9%

FLASH POINT 5.0%

FLASH POINT 25%

FLASH POINT 50%

FLASH POINT 75%

FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 67 of 93

15.2.5 Medium Aeroplane Wing Tank

(short mission 500 nm)

 (medium mission 1,000 nm)

(long mission 2,400 nm)
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 68 of 93

15.2.6 Small Aeroplane Centre Wing Tank (without heat source)

SMALL AEROPLANE CENTRE WING TANK w ithout HEAT SOURCES - LONG MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

SMALL AEROPLANE CENTRE WING TANK w ithout HEAT SOURCES - MEDIUM MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

SMALL AEROPLANE CENTRE WING TANK w ithout HEAT SOURCES - SHORT MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 69 of 93

15.2.7 Regional Turbofan Centre Wing Tank (without heat source)

REGIONAL TURBOFAN AIRPLANE CENTRE WING TANK - LONG MISSION

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3

TIME (HOURS)

FUEL TEMPERATURE (F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT)

COLD 1%

COOL 25%

AVERAGE 50%

WARM 75%

HOT 95%

VERY HOT 99%

EX HOT 99.9%

FLASH POINT 5.0%

FLASH POINT 25%

FLASH POINT 50%

FLASH POINT 75%

FLASH POINT 95%

ALTITUDE FEET

REGIONAL TURBOFAN AIRPLANE CENTRE WING TANK - SHORT MISSION

-40

-20

0

20

40

60

80

100

120

140

0 1 2

TIME (HOURS)

FUEL TEMPERATURE (F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT)

COLD 1%

COOL 25%

AVERAGE 50%

WARM 75%

HOT 95%

VERY HOT 99%

EX HOT 99.9%

FLASH POINT 5.0%

FLASH POINT 25%

FLASH POINT 50%

FLASH POINT 75%

FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 70 of 93

15.2.8 Large Aeroplane Centre Wing Tank (with heat source)

LARGE AEROPLANE CENTRE WING TANK - LONG MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

160

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT) / FUEL LOAD (LBS)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET FUEL LOAD LBS

LARGE AEROPLANE CENTRE WING TANK - MEDIUM MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

160

0 1 2 3 4 5 6 7 8 9 1 0 1 1

TIME (HOURS)

FUEL TEMPERATURE °F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT) / FUEL LOAD (LBS)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET FUEL LOAD LBS

LARGE AEROPLANE CENTRE WING TANK - SHORT MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

160

0 1 2 3 4 5 6 7

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

ALTITUDE (FT) / FUEL LOAD (LBS)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET FUEL LOAD LBS
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 71 of 93

15.2.9 Small Aeroplane Centre Wing Tank (with heat source)

SMALL AEROPLANE CENTRE WING TANK - MEDIUM MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT) / FUEL (lbs)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET FUEL LOAD LBS

SMALL AEROPLANE CENTRE WING TANK- SHORT MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT) / FUEL (lbs)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

HOT 95% VERY HOT 99%

EX HOT 99.9% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET FUEL LOAD LBS

SMALL AIRPLANE CENTRE WING TANK - LONG MISSION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

ALTITUDE (FT) / FUEL (lbs)

COLD 0.01 COOL 0.25

AVERAGE 0.5 WARM 0.75

HOT 0.95 VERY HOT 0.99

EX HOT 0.999 FLASH POINT 0.05

FLASH POINT 0.25 FLASH POINT 0.5

FLASH POINT 0.75 FLASH POINT 0.95

ALTITUDE FEET FUEL LOAD LBS
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 72 of 93

15.2.10 Medium Aeroplane Centre Wing Tank (with heat source)

MED IUM AEROPLANE CENTRE WING TANK - LONG MISSION WITH VENTILATION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6 7 8 9 1 0 1 1

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

VERY HOT 99% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

MED IUM AEROPLANE CENTRE WING TANK - MEDIUM MISSION WITH VENTILATION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4 5 6

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

VERY HOT 99% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET

MEDIUM AEROPLANE CENTRE WING TANK - SHORT MISSION WITH VENTILATION

-40

-20

0

2 0

4 0

6 0

8 0

100

120

140

0 1 2 3 4

TIME (HOURS)

FUEL TEMPERATURE (°F)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

ALTITUDE (FT)

COLD 1% COOL 25%

AVERAGE 50% WARM 75%

VERY HOT 99% FLASH POINT 5%

FLASH POINT 25% FLASH POINT 50%

FLASH POINT 75% FLASH POINT 95%

ALTITUDE FEET
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 73 of 93

15.3 Exposure Analysis Results Charts

15.3.1 Large Aeroplane Wing Tank

average 1.6%

15.3.2 Small Aeroplane Wing Tank

average 3.0%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 74 of 93

15.3.3 Business Jet Wing Tank

average 5.6%

15.3.4 Regional Turbofan Wing Tank

average < 0.1%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 75 of 93

15.3.5 Small Aeroplane Centre Wing Tank (without heat source)

average 0.9%

15.3.6 Regional Turbofan Centre Wing Tank (without heat source)

average 3.0%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 76 of 93

15.3.7 Large Aeroplane Centre Wing Tank (with heat source)

average 26.7%

15.3.8 Small Aeroplane Centre Wing Tank (with heat source)

average 32%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 77 of 93

15.3.9 Medium Aeroplane Centre Wing Tank

(with heat source and directed forced ventilation)

average 3.9%

15.3.10 Large Aeroplane Centre Wing Tank With Insulation (of heat sources)

average 18.9%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 78 of 93

15.3.11 Large Aeroplane Centre Wing Tank With Ventilation (of heat source)

average 22%

15.3.12 Large Aeroplane Centre Wing Tank With Redistributed Fuel

average 20.3%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 79 of 93

15.3.13 Large Aeroplane Centre Wing Tank With 120°F Flashpoint

average 6.5%

15.3.14 Large Aeroplane Centre Wing Tank With 130°F Flashpoint

average 3%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 80 of 93

15.3.15 Large Aeroplane Centre Wing Tank With 140°F Flashpoint

average 1.2%

15.3.16 Large Aeroplane Centre Wing Tank With 150°F Flashpoint

average 0.4%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 81 of 93

15.3.17 Medium Aeroplane Centre Wing Tank With 120°F Flashpoint

average 0.5%

15.3.18 Medium Aeroplane Centre Wing Tank With 130°F Flashpoint

average 0.3%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 82 of 93

15.3.19 Medium Aeroplane Centre Wing Tank With 140°F Flashpoint

average 0.1%

15.3.20 Medium Aeroplane Centre Wing Tank With 150°F Flashpoint

average < 0.01%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 83 of 93

15.3.21 Small Aeroplane Centre Wing Tank With 120°F Flashpoint

average 16.5%

Flashpoint

average 9.5%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 84 of 93

15.3.23 Small Aeroplane Centre Wing Tank With 140°F Flashpoint

average 4.0%

Flashpoint

average 1.1%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 85 of 93

15.3.25 Large Aeroplane Centre Wing Tank COMBINATION of Insulate Heat

Sources AND 120°F Flashpoint

average 3.5%

15.3.26 Large Aeroplane Centre Wing Tank COMBINATION of Insulate Heat

Sources AND 130°F Flashpoint

average 1.3%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 86 of 93

15.3.27 Large Aeroplane Centre Wing Tank With Ground Inerting

average 0.8%
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 87 of 93

15.4 Exposure Analysis Process

A Monte Carlo analysis was run to determine the percent of fuel tank

temperature above flashpoint. The randomised variables were; flight length,

ground temperature and flashpoint. The fuel tank temperature was input to the

Monte Carlo analysis. Models of different aeroplane fuel tanks were developed

and run for specified ground temperatures.

Input Data

There were four data inputs into the Monte Carlo analysis:

a) Aeroplane type; this is needed to determine the set of flight lengths to

use. Task Group 8 provided this data.

b) Fuel tank temperature; this file determines which data file to load. This is

independent of the aeroplane type as there are various models for the

same aeroplane type such as; wing tank, centre wing tank with heating

and centre wing tank without heating. This data was generated from

various sources.

c) Flashpoint; this is needed to determine the range of flashpoints used.

The basic flashpoint range was received from Task Group 6. The other

ranges used were generated within Task Group 5 and have less spread.

The basic flashpoint data was used for most analyses.

d) The final input is the seed for the random number generator. The same

seed was used for basic analyses of different models. Several seeds

were used to determine the variance of the random numbers generated.

Load Aeroplane Data

With the fuel tank temperature file defined, loading the data is a matter of using

the correct format and assigning the data to the correct variables.

Random Numbers Generation

The analysis was started assuming 10,000 runs were required, with 3

randomised variables, this became 30,000 random numbers. A uniform random

number generator that gave numbers between 0 and 1 generated the numbers.

The first 10,000 numbers were assigned to the ground temperature probability.

As the distribution for these did not have data below 1% or above 99.9%, any

numbers outside of this range were assigned to these values. The values were

left as probability since the temperature files data were listed as probability.

The second 10,000 numbers were assigned to the flashpoint probability. Using

the appropriate flashpoint distribution and the random numbers, flashpoints were

generated for the 10,000 runs.

The last set of 10,000 was assigned to mission length. Using the appropriate

mission length distribution and the random numbers, mission lengths were

determined (short, medium or long).
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 88 of 93

Percentage Calculation

For each of the 10,000 runs, the ground temperature for each run is used to

interpolate the fuel temperature profile from the appropriate fuel temperature

data for each run’s flight length. Using the altitude data for each run’s flight

length and the run’s flashpoint, the flashpoint for each segment of the flight is

calculated.

With the fuel temperature and flashpoint profiles created, the flight segments

where the fuel temperature is above the flashpoint are determined. The time

spent in each segment is summed and divided by the total length of the flight.

This gives the percent of each particular flight where the average fuel

temperature is above the flashpoint. The percentages are then averaged, for

the 10,000 runs, to produce the average percentage of time that the average fuel

temperature is above the flashpoint.

Process Flow Charts

Chart 15.4.1 Monte Carlo Analysis of Fuel Tank Temperature

Chart 15.4.2 Load Aeroplane Data

Input Fuel

Flashpoint

(15.4.3)

Generate

Random

Numbers

(15.4.4)

Calculate

Percentage of

Flight Length

above Flashpoint

(15.4.2)

Load Aeroplane

Data

Input Aeroplane

Type

Load Particular

Aeroplane Data

from Disk

Find Zero Time Points

to Segregate The

Missions

Assign the Flight Time

Data to Variable:

TIME

Assign the Fuel

Temperature Data to

Variable: TEMP

Assign the Altitude

Data to Variable:

ALT

Define the Temperature

Percentages and Assign to

Variable: TEMP_PERC

Start

Done Loading
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 89 of 93

Chart 15.4.3 Generate Random Numbers

Generate 30,000

Random Numbers

ranging from 0 to 1

Assign the First

10,000 to Ground

Temperature

Probability (GTP)

Variable =

TEMP_PERC

Reassign those

GTP=0.01

Reassign those

GTP=0.01

Assign the Second

10,000 to Ground

Flashpoint Probability

Variable = FPP

Using the Flashpoint

Distribution and FPP

Determine Flashpoint

Temperatures Variable

=FL_POINT

Assign the Third

10,000 to Mission

Length Probability

Variable = MLP

Using the Length

Distribution and MLP

Determine Mission

Lengths 1=short

;2=medium 3=long

Variable = LNGTH

N O

N O

YES

Start

Done Generating

Any

GTP<.999?

Any

GTP<0.01?
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 90 of 93

Chart 15.4.4 Calculate Percentage of Flight Length Above Flashpoint

Loop Through All 3

Flight Lengths

Interpolate a Temperature profile

based on the appropriate

GR_TEMP’s using the TEMP’s

Variable =T

Calculate the altitude corrected

flashpoint for each FL_POINT using

the appropriate ALT’s variable

FL_PT

Using T and FL_PT calculate the

percentage of each Flight for this

flight length where T>FL_PT

N O

N O

YES

Start

Done Calculating

Any of LNGTH

= appropriate

Flight Length?

Are All 3 Flight

Lengths Done?
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 91 of 93

15.5 ULLAGE SWEEPING TESTING

Preliminary laboratory scale tests were conducted to study the concept of ullage

sweeping. The test set up was a 55-gallon (US) drum loaded with 1 gallon (US)

of fuel. See Figure 15.5.1. The test tank was heated for four hours to a fuel

temperature of 120°F which was 14°F above the flashpoint of the fuel. The fuel

vapour concentration was measured at two locations within the test tank and

several times during the test. The concentration meter gave results in terms of

%LFL which is the fuel vapour concentration as a fraction of the lower

flammability limit of 0.6% by volume. For example, 100%LFL on the meter

equals 0.6% by volume, and so 50%LFL equals 0.3% by volume. Results of the

heating test are shown in figure 15.5.2.

After the tank had been heated for four hours, the ullage was swept with ambient

air for 11⁄2 hours. The flow rate of the air was 25 standard cubic feet per hour,

(SCFH), which simulates 1 test tank volume change in 20 minutes. The fuel

vapour concentration was reduced to 80%LFL in the first 30 minutes and to

60%LFL after 11⁄2 hours. Test results are shown in Figure 15.5.3. During this test

approximately 3% of the fuel mass was evaporated and lost through the vent.

The fuel vapour concentration was measured with a custom built, 10 channel

combustible gas monitoring system from Mine Safety Appliance Corp. The gas

samples are measured with a low temperature catalytic bead sensor utilising

Ultima combustible gas transmitters. The unit measures percent lower

flammability limit by sampling the fuel vapour at rates of one litre per minute. The

unit was acquired from Autoline Controls of Redmond, Washington, USA.
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 92 of 93

Figure 15.5.1 Fuel Tank Ullage Sweeping / Vapour Condensing Test Set-up PUMP HEAT EXCHBV

T

5"

T

T

P

T

SCV

FUEL

W ATER

T

STEAM IN

STEAM OUT

T

AIRINLET

F

U

E

L

T

A

N

K

U

L

L

A

G

E

S

W

E

E

PIN

G

/

V

A

P

O

R

C

O

N

D

E

N

SIN

G

T

E

S

T

S

E

T

U

P

L

E

G

E

N

D

SCV- STEAM CON TROL VALVE/W ATER TEM PER ATUR E CONTROLLERBV- BA LL VA LVE

T -THERMOCOUPLEP- PRESSURE TAP

FLOW METER F

T

5"

T

P

T

SMALLBUCKET

CONDENSATE

F

VENT

COOLINGFLOW IN

COOLINGFLOW OUT

55 GAL DRUM CONDENSER

F

T

F

VAPOR SAMPLE VS

FUEL SAMPLE

FS

VS

VS

T

`

FS

FS
6 July 1998

Task Group 5 – Fuel Vapour Reduction PAGE 93 of 93

Figure 15.5.2 Flammability of a Nearly Empty Fuel Tank

Figure 15.5.3 Effect of Ullage Sweeping by Ambient Airflow of 25 SCFH

0

10

20

30

40

50

60

70

80

90

100

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00

TIME AFTER FUEL ADDED TO TANK - HOURS

%

L

F

L

FUEL TEMP = 120 DEG F

JET A (FLASH POINT = 106 DEG F)

PORT 1

AT TOP OF ULLAGE SPACE

PORT 2

1 INCH ABOVE FUEL SURFACE

FUEL QUANTITY IS 1 GALLON IN A 55 GALLON TANK

0

10

20

30

40

50

60

70

80

90

100

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

TIME AFTER ULLAGE SWEEPING STARTED - HOURS

%

L

F

L

PORT 2

1 INCH ABOVE FUEL SURFACE

PORT 1

LOCATED AT TOP OF ULLAGE SPACE

FUEL TEMP. = 120 DEG F

JET A (FLASH POINT = 106 DEG F)

FUEL QUANTITY IS 1 GALLON IN A 55 GALLON TANK
Fuel Properties -

Effect on Aircraft and

Infrastructure

Task Group 6/7

Aviation Rulemaking

Advisory Committee

ARAC

JAA FAA

THE PUBLIC
FINAL REPORT—Revised 7/15/98a

Task Group 6/7 on Fuel Properties

Report to the Fuel Tank Harmonization Working Group of the

FAA Aviation Rulemaking Advisory Committee

1.0 ABSTRACT

The Fuels Properties Task Group was charged with assessing the feasibility of using jet

fuel with a higher flash point in the civil transport airplane fleet than required by current

Jet A/Jet A-1 Specification, as a means of reducing the exposure of the fleet to

flammable/explosive tank vapors. This report describes the efforts performed by Task

Group 6/7 for the Aviation Rulemaking Advisory Committee (ARAC) Fuel Tank

Harmonization Working Group.

Raising the minimum flash point of jet fuel will result in a combination of changes to

other fuel properties, such as viscosity. The magnitude of change is dependent on the

severity of flash point increase. The engine and APU manufacturers have no experience

base for such modified fuels, and are concerned about the risk of adverse impact on

altitude relight and low temperature operations (especially Extended Twin Operations,

ETOPS). Mitigating actions, including hardware modifications, fuel specification

revisions, use of additives and revised operational limits, have also been reviewed.

Dependent on magnitude of change, laboratory, rig and/or full-scale engine testing on

reference fuels may be required to quantify the impacts.

Raising the minimum flash point could also significantly raise the manufacturing cost and

decrease the availability of the modified jet fuel. The predicted impact on jet fuel price

could be significant. Again, the higher the flash point, the more severe the affect.

The fuel impacts are most severe outside of the U.S. because of the differences in

overseas refinery configurations and product demand. Some countries indicated that

changes in flash point are not viable options to which they would subscribe (Canada,

United Kingdom, New Zealand, Australia, Japan, Russia and the Commonwealth of

Independent States).
Report of Task Group 6/7 on Fuel Properties

2

2.0 SUMMARY

The Fuels Properties Task Group (Task Group 6/7) was formed by the FAA-ARAC Fuel

Tank Harmonization Working Group to assess the impacts of raising the minimum flash

point, and possibly lowering the freeze point, of commercial Jet-A/A-1 aviation fuel.

Task Group 6/7 was comprised of representatives from the engine powerplant and

auxiliary power unit (APU) manufacturers, petroleum industry, airframe manufacturers,

air carriers, and the Department of Defense. The impacts on Engines, APU's, hardware

manufacturers, jet fuel availability and cost are based on evidence and information drawn

from surveys conducted of refiners in the U.S. (by API/NPRA), Europe (by Europia), and

Japan (by PAJ), as well as responses from other international refiners.

The findings of the Task Group are summarized below:

2.1 Impact on Engine Integrity, Operation and Maintenance

The predicted fuel changes identified will result in a combination of fuel properties that

can fall outside the current experience base. The magnitude of property change and

potential introduction of new molecules increases with increasing flash point. Evaluation

of such changes identifies the following key issues:

• Increases in low temperature viscosity and decreases in volatility are fuel property

changes that may adversely impact operation /safety including failure of engine/APU

cold starts and high altitude relight (including cold soak relight).

• Reduced fuel pump life due to increased wear rate when operating on lower lubricity

fuels which may result in component failure.

• The following increased maintenance cost effects were identified but not quantified:

⇒ Increased maintenance of combustion and turbine components due to poorer

combustion quality.

⇒ Fuel system and injector nozzle cleaning at more frequent intervals due to

fuel lacquering and coking.

⇒ Reduced fuel pump life due to increased wear rate.

• Depending on the magnitude of the flash point increase, laboratory rig or full engine

testing on representative high flash point reference fuels may be required to fully

evaluate/quantify these effects.

• Emissions testing to verify EPA / ICAO regulatory requirements becomes

increasingly probable with magnitude of flash point change.

• Mitigating actions were examined. They may include: hardware modifications, fuel

specification revisions, and revised aircraft operational limits. The use of new

additives will require extensive evaluation and approval programs.
Report of Task Group 6/7 on Fuel Properties

3

• Any change to the minimum flash point will also necessitate the installation of heated

auxiliary power units at an estimated cost of $1 million per APU model.

• The magnitude of the flash point change will dictate the actions required and cost

incurred to continue to meet civil airworthiness requirements.

2.2 Impact on Jet Fuel Properties

• An increase in the jet fuel flash point specification will result in shifts of fuel

properties. At some increase in the flash point specification, a high flash Jet-A

becomes a new fuel, never before produced or used, with properties unlike any other

fuel. For example, the viscosity is expected to be significantly higher than JP-5.

• The uncertainty concerning jet fuel properties resulting from a large flash point

specification increase is a significant concern. The engine manufacturers have no

experience base for such modified fuels.

• As the minimum flash point is increased, the average flash point of the jet fuel pool is

predicted to be 12-15°F (6-8°C) above the flash point specification in the U.S. due to

pipeline specifications and test method precision

• The shifts in jet fuel properties are expected to occur by three mechanisms:

1. By changes in the distillation cut points of conventional refining.

2. By creating incentives for jet fuel to be produced by modified processing

schemes.

3. By causing localities relying on unique refinery configurations or crude sources to

experience “magnified” shifts in jet fuel properties.

2.2.1 Changes in Distillation Cut Points of Conventional Refining

• The impact of mechanism 1 was quantified by the Jet Fuel Properties Survey. The

results found potentially important adverse impacts on:

⇒ 10% Boiling Point

⇒ Viscosity

⇒ Aromatics Content

⇒ Smoke Point

⇒ Density

⇒ Jet Fuel Availability

− Jet fuel distillation yield is reduced by more than 1% per °F flash point

increase.

− Many of the crude oils examined cannot produce Jet A-1 with a very high

flash point.
Report of Task Group 6/7 on Fuel Properties

4

− Extrapolations in the growth of jet fuel consumption indicate pressure already

exists on jet fuel availability and properties. The yield loss associated with an

increased flash point specification exacerbates this situation.

2.2.2 Creating Incentives to Produce Jet Fuel by Modified Processing

• The yield loss associated with an increased flash point specification can create

incentives for jet fuel to be produced by modified processing schemes. The impact

could not be quantified on the short time scale of this study but the use of

unconventional refinery processing is a significant concern:

⇒ Larger flash point changes result in greater incentives for the use of modified

processing schemes.

⇒ One example of an unconventional processing scheme results in the increased use

of hydrotreated cracked stocks in jet fuel. This could push certain properties

towards the specification limits resulting in adverse impacts on:

− Aromatics Content

− Smoke Point

− Thermal Stability

⇒ The production of jet fuel by a different mix of conventional processing schemes

should not impact fuel properties as much as the use of unconventional

processing. However, the increased use of severe hydrotreating (a conventional

process) is expected to negatively impact fuel lubricity.

2.2.3 Magnified Shifts in Localities with Unique Refinery Configurations or Crude

 Sources

• Localities relying on unique refinery configurations or crude sources may experience

“magnified” shifts in jet fuel properties. Although this could not be quantified in the

short time frame of this report, the following examples illustrate this concern:

⇒ Areas using predominately naphthenic crude oils (such as those found in

California) might experience viscosity shifts much larger than average resulting in

a significant number of batches being produced close to the specification limit.

• The increased use of severe hydroprocessing, to restore fuel availability, may cause

some localities to receive mostly low lubricity fuel.

• Some fuel properties may be addressed by the use of additives.
Report of Task Group 6/7 on Fuel Properties

5

2.3 Impact on Jet Fuel Availability and Manufacturing Cost

• The higher the flash point the more severe the impact.

• Higher flash points could result in significant shortfalls of jet fuel availability and

could require at least five years for industry to endeavor to meet jet fuel demand.

• In the U.S., average refinery shortfalls of about 5% at 120 degrees and about 20% at

150 degrees could occur (weighted average, assuming 1 - 2 years lead time

• Outside the United States, requirements for higher flash point jet fuels could result in

production shortfalls of 12% at 120 degrees and up to 49% at 150 degrees (weighted

average, assuming 1 - 2 year lead time).

• The API survey results address jet fuel demand at 1998 levels. The survey does not

address long-term changes in jet fuel demand, which is projected to grow by 6 - 15%

more than other refined products by 2010. Environmentally driven reformulation of

other fuels, (e.g., toward “light” diesel) will further increase demand for the jet fuel

portion of the barrel. These pressures are likely to amplify the difficulties predicted

for the 1998 level.

• Requirements for higher flash point jet fuels could result in United States refinery

production cost increases of 1.5-2.2 cents per gallon at 120 degrees and 6-7.5 cents

per gallon at 150 degrees (assuming 7% ROI). Based on current U.S. jet demand,

this translates into annual costs of $350-520 million at 120 degrees and $1.4-1.7

billion at 150 degrees.

• Outside the United States, requirements for higher flash point jet fuel will result in

refinery production cost increases of 3-15 cents per gallon at 120 degrees and more

that 20 cents per gallon at 150 degrees. Based on current jet demand, this translates

into annual costs of $320-900 million for the 120 to 150 range of flash points

(assuming 15% ROI).

• The potential for increased production cost and decreased capacity could dramatically

impact the market price of jet fuel. Price elasticity models have been used to

calculate the increases in price that could occur for various combinations of capacity

reductions and price elasticities. Based on a price elasticity of 0.2, the annual cost is

$4 to $13 billion. No substitutions for jet fuel were assumed to be available.

2.3.1 Impact Outside the United States

• The difference between U. S. and non-U.S. availability and cost result from:

⇒ The lower yields associated with the manufacture of lower freezing point Jet

A-1, which is the predominant jet fuel outside the U.S.

⇒ Markedly different regional petroleum product demand and refinery structure.
Report of Task Group 6/7 on Fuel Properties

6

• Based on the surveys, more refiners worldwide than in the U.S. reported that it is not

feasible to produce higher flash point jet fuels in the current refinery installations.

• The Task Group attempted to determine the potential for localized supply and

demand imbalances due to increased flash point requirements. Results of informal

surveys showed that individual refineries vary greatly in their flexibility to provide

the same fuel volume at various flash points, but it was not generally possible to

pinpoint specific airport supply imbalances in the U.S. Australia, New Zealand, and

Japan were identified as subject to potential shortages of Jet A-1 fuel if flash point

requirements are increased.

2.4 Other Issues

• As the minimum flash point increase, more refiners are likely to have difficulty

producing gasoline and diesel that complies with current state and federal

environmental regulations.

• Engine emissions may need to be remeasured for reporting purposes, and some

number of engine models may been to be recertified.

• Commercial airlines will continue to uplift low flash fuels particularly in Russia and

the Commonwealth of Independent States (C.I.S.) and Wide-Cut fuels in Northern

Canada. In today's global market, there is no practical way to avoid mixing fuels

from different parts of the world.

• Cold climate operation could become an issue at higher minimum flash points.

Increasing the flash point would reduce the more volatile, low-boiling components of

the fuel, which in turn leads to an increase in viscosity and exacerbates an already

tenuous cold starting situation and APU in-flight starting problems.

• Russian aircraft and engines have not been designed to operate on high flash fuel.

Impacts on their operability and airworthiness have not been determined.

The aviation fuel community has a high confidence level with currently produced fuel

because of a long experience base. Task Group 6/7 cannot readily measure the existing

margin to alter the fuel for all aircraft engine types. Effects from changes at a single source

are difficult to determine because they are usually lost in the pool fuel volume, so that

continuous operation at the extremes of the property limits is infrequent. Conversely,

changes to the jet fuel pool as a whole, must of necessity, be viewed with concern. The

concern for a change in minimum flash point to 110-120oF is significant; for a change to

140oF it is many times higher because refiners can be expected to change production

methods and reduce specification margins on a broad scale. Possible mitigating actions to

offset adverse effects on engine and APU operation might include hardware modifications,

adjustments and re-calibrations. Other revisions of fuel specification requirements may be

necessary in addition to the flash point increase the impact of such additional changes on

availability has not been evaluated.
Report of Task Group 6/7 on Fuel Properties

7

3.0 TABLE OF CONTENTS

 1 ABSTRACT

 2 SUMMARY

2 Impact on Engine Integrity, Operation and Maintenance

 3 Impact on Jet Fuel Properties

 3 Changes in Distillation Cut Points of Conventional Refining

 4 Creating Incentives to Produce Jet Fuel by Modified Processing

 4 Magnified Shifts in Localities with Unique Refinery

Configurations or Crude Sources

 5 Impact on Jet Fuel Availability and Manufacturing Cost

5 Impact Outside the U.S.

 6 Other Issues

 7 TABLE OF CONTENTS

10 INTRODUCTION

11 REFERENCES

12 BACKGROUND

12 The Development of Specifications

14 The Manufacture of Jet Fuel

14 Conventional Processes

14 The Crude Unit

16 Jet Fuel Hydrotreating/Hydrodesulfurization

17 Merox Process

17 High Pressure Hydrotreating/Hydrocracking

18 Catalytic Cracking/Thermal Cracking

19 Refinery Configuration Issues

19 Advanced Processes for Jet Fuel Production

19 Aromatics Saturation of Cracked or Aromatic Streams

19 Jet Fuel Synthesis by Fischer-Tropsch Chemistry

19 Experimental Processes for Jet Fuel Production

19 Catalytic Dewaxing

20 Jet Fuel Synthesis by Alkylation

20 Transportation from Refinery Gate to Airport

21 Aircraft Fuel System Design

22 Current Jet Fuel Demand

23 Demand for Other Distilates

24 Military Experiences

27 DESIGN ALTERNATIVES
Report of Task Group 6/7 on Fuel Properties

8

28 INSTALLATION/RETROFIT REQUIREMENTS

28 Fuel Phase-in Requirements

28 Retrofit Requirements

29 TECHNICAL DATA

29 Flash Point

29 Tank Ullage Flammability

32 Flash Point Methods and Significance

35 Flash Point Distributions

35 United States Data

35 U.K. Defense Research Agency Flash Point Data

36 European Flash Point Distribution

37 Average Flash Point Distribution Curve Worldwide

38 Flash Point Margins

40 Flash Point Predictions

43 Fuel Property Effects

43 Fuel Property Effect Predictions

43 Introduction

44 The Impact of Modified Distillation Properties: Jet Fuel

Properties Survey

50 The Impact of Modified Jet Fuel Refining

50 Local Impacts

51 The Impact of Uncertainties in Fuel Properties

51 Fuel Property Effects on Airframes

51 Material Compatibility

51 Heat Content and Density

52 Freezing Point

53 Viscosity

53 Fuel Property Effects on Engines & Auxiliary Power Units

53 General

54 Flash Point and Distillation

54 Viscosity

57 Aromatics and Smoke Point

57 Sulfur Content

58 Thermal Stability

58 Freeze Point (Cold Flow Properties)

59 Lubricity (Lubricating Qualities)

59 Heat of Combustion and Density

59 APU Operational Impacts

60 Ground Infrastructure & Fungibility

61 Environmental Effects

61 Aircraft Emissions

62 Jet Fuel Manufacturing Emissions

63 Evaporative Emissions

64 Additives in High Flash Jet Fuels

64 Antioxidants
Report of Task Group 6/7 on Fuel Properties

9

65 Metal Deactivator Additive

65 Static Dissipator Additive

65 Corrosion Inhibitor/Lubricity Additives

66 Fuel System Icing Inhibitor (Anti-icing additive)

66 Miscellaneous Additives

66 Research Opportunities for Additives

68 AIRWORTHINESS REQUIREMENTS

69 SAFETY

69 Operation on Low/High Flash Fuels

69 Operation in Cold Climates

69 Canada

69 Scandinavia and the Baltic States

70 Russia and the C.I.S.

70 Russian and C.I.S. Aircraft Operation on High Flash Fuel.

70 Changing the Experience Database

73 COST AND AVAILABILITY IMPACT OF HIGH FLASH JET FUEL

74 Fuel Cost Estimates

74 United States

74 Europe

75 Rest of the World

75 Availability of Fuel

75 United States

75 Europe

75 Rest of the World

76 Future Projection of Jet Fuel Demand

77 Local Situations

78 Impact of Availability on Pricing

80 Effects on Crude Oil Selection

81 Effect on Refining

83 Effect on APU Cost

84 APPENDIXES

App. 1 Final Report API/NPRA Aviation Fuel Properties Survey

App. 2 EUROPIA Effect of Jet A-1 Flash Point on Product Availability and

Properties

App. 3 PAJ Impacts of Jet A-1 Flash Point Changes

App. 4 Fuel Property Effects on Engines (Section 9.3.2, Table 1)

App. 5 Estimate of Ten-Year Cost of Fuel Change
Report of Task Group 6/7 on Fuel Properties

10

4.0 INTRODUCTION

The purpose of this report is to evaluate the availability, cost, and risk associated with

changing to a high flash point jet fuel for commercial aviation.

In November 1997, the FAA requested that the American Petroleum Institute (API)

examine the ramifications (production, cost, schedule) of the United States commercial

aviation industry utilizing a Jet A/A-1 type of fuel with a minimum flash point of

140oF(60oC) to 150oF(66oC) in place of the current Jet A/A-1 fuel. The FAA also

requested that the API participate in a dialogue with FAA and industry technical

specialists regarding this proposal. In a subsequent letter from the FAA dated February

26, 1998 to API, the petroleum industry was asked by the FAA-ARAC Fuel Tank

Harmonization Working Group to develop and compile data on the availability of a Jet A

type fuel (both domestic and international) with a higher flash and a possible lower

freezing point. The FAA requested the assessment of possible impact on production

volumes; short- and long-term cost increments and capital investments to make up any

loss in production. For this assessment, flash points of 120oF(49oC) to 150oF(66oC) in

ten degree increments were identified, as well as freezing points of -40oF(-40oC) and -

53oF(-47oC).

The API, in conjunction with the National Petrochemical & Refiners Association

(NPRA) conducted a survey of individual refineries to assess the availability and cost of

producing high flash point fuel for commercial aviation in the U. S., Europe, and other

parts of the world. This report presents the combined results of the API/NPRA survey

(Appendix 1), European (EUROPIA) survey (Appendix 2), and the PAJ (Petroleum

Association of Japan) survey (Appendix 3) and correspondence with some refineries in

other parts of the world.

The aviation industry representatives assigned to Task Group 6/7 include jet fuel

suppliers who are represented by the API, airlines, engine, auxiliary power unit (APU),

and airframe manufacturers as well as government representatives, including the FAA.

This Task Group has investigated the complex issues associated with raising the flash

point and lowering the freezing point of commercial aviation jet fuel. The impacts on

aircraft engines, APUs, aircraft systems, fuel transportation, fuel availability, and fuel

cost as well as the possible implications on the production of other petroleum products

have been studied. In addition, the Task Group has considered flight safety, certification

issues, emissions, military experience, and the impact on fuel price.
Report of Task Group 6/7 on Fuel Properties

11

5.0 REFERENCES

References are included in the individual sections.
Report of Task Group 6/7 on Fuel Properties

12

6.0 BACKGROUND

6.1 The Development of Specifications

Just as military jet operation preceded commercial flights by more than 10 years, military

fuel and commercial specifications showed the same time lag. The earliest U. S. Air

Force specifications for grades JP-1 and JP-2 never achieved wide usage. Published in

1947, grade JP-3 maximized availability by a blend of kerosene and gasoline with the

vapor pressure of aviation gasoline. After this wide-cut fuel caused high boiling losses in

high altitude operations, subsequent changes were directed toward tightening quality,

particularly volatility. First the wide-cut JP-4 reduced vapor pressure drastically in 1951;

then the kerosene-type JP-8 removed lighter components altogether in 1979. By closely

modeling JP-8 after the commercial Jet A-1 grade the Air Force hoped to maximize its

availability. These volatility decreases were possible in part because of a continuing

decrease in DOD fuel consumption, but JP-8 caused numerous performance problems,

particularly with older equipment. In 1952 the U.S. Navy developed JP-5, a low volatility

fuel, to protect aircraft carrier tankage. Because of the restrictive combination of high

flash point and low freezing point and because its use has been primarily restricted to

carrier operations, this fuel has always had limited use and availability.

ASTM specifications have included both kerosene and wide-cut grades since 1959, but

the wide-cut grade, Jet B, has seen no use in the U. S. and only limited use outside the

U.S.. Instead the Jet A grade has represented the best compromise between the properties

of commercial kerosene and the requirements of aircraft operation within the U.S.. For

international operations the Jet A-1 grade followed the British lead with a lower freezing

point. Over the years the compromise between availability and performance has held up

well except for two specification areas where shortages forced relaxations. Due to supply

dislocations which required blending with less desirable crudes in 1973 an increase in

aromatic content and a decrease in smoke point was permitted, provided the deviations

were reported to the operators. At the same time the freezing point of Jet A-1 was raised

from -50 to -47°C, a relaxation which was carried over into other specifications. Today

the reporting requirements have been dropped and the decreases in combustion

requirements have been made permanent in recognition of satisfactory aircraft

performance. The changes were made only after reviews of equipment performance to

assure the absence of unexpected secondary effects.

Selected requirements of U. S. military and commercial specifications are summarized in

Table 1, attached. Only those properties thought to be influenced by an increase in flash

point or freezing point have been included. For a later comparison Table 1 also contains

the same requirements of the Russian specification, TS-1.

Overall, the current jet fuel specifications are experience based and tend to reflect

solutions to past problems. Specifications, therefore, cannot be expected to anticipate new

problems that might occur with fuels meeting current specifications. An example is the

current focus on fuel lubricity difficulties that seem to have increased as refinery

processing has been changing. Because this property has not caused difficulties in past
Report of Task Group 6/7 on Fuel Properties

13

commercial operations it is not currently limited. However, as this problem has become

more prominent, efforts are underway to modify specifications to control this property. In

the case of fuels produced from novel sources or new processes it is necessary to review

the performance of such products before deciding on the applicability of existing

specifications.

Specification→ ASTM D1655 Joint Check List MIL-T-5624 MIL-T-5624 GOST 10227

 Grade → Jet A/A-1 Jet A-1 JP-5 JP-4 TS-1

Property ↓

Aromatics, vol. % Max. 25 22 a25.0 25.0 22

Sulfur, mass % Max. 0.3 0.30 0.40 0.40 0.25

Distillation, °C (°F)

 IBP Report Report Report 150 Max.

 10% rec. Max. 205 (400) 205 (400) 206 (403) Report

 20% rec. Report Report 100 max.

 50% rec. Report Report Report 125 max. 195 Max.

 90% rec. Report Report Report Report 230 Max.

 98% rec. 250 Max.

 Final BP Max. 300 (575) 300 (575) 300 (575) 270

Flash point, °C (°F) Min. 38* (100) 40* (104) 60** (140) 28 (82)

RVP, kPa (psi) 14 - 21

 (2.0-3.0)

Density, kg/m3775 – 840 775 – 840 788 - 845 775 Min.

Freezing point, °C (°F)

Max.

-40 b (-40) -47 (-53) -46 (-51) -58 (-72) -50 (-58)

Viscosity @-20°C, cs Max. 8 8.0 8.5 8 @ -40

Specific energy, MJ/kg Min. 42.8 42.8 42.6 42.8 42.9

Smoke point, mm or Min. 25 25 19 20.0 25

Smoke point , mm + Min. 18 19

Naphthalenes, vol. % Max. 3.0 3.0

JFTOT @ 260°C

c

 Tube rating Max. < 3 < 3 < 3 < 3 18 mg/100 mL

Max.d

 Pressure drop, mm Hg Max. 25 25 25 25

Additives

 Anti-icing, vol. %

 Antioxidant

 Corrosion inhibitor/

 Lubricity agent

 Metal deactivator

 Conductivity improver

Agreement

Permitted

Agreement

Permitted

Permitted

Agreement

Agreemente

Agreement

Permitted

Required

0.15 – 0.20

Agreemente

Required

Permitted

Not permitted

0.10 – 0.15

Agreemente

Required

Permitted

Required

Agreement

Agreement

Agreement

Agreement

Conductivity, pS/m 50 – 450 f50 - 450 150 – 600 50 – 600f

Section 6-1, Table 1--Critical Fuel Properties in Specifications
Report of Task Group 6/7 on Fuel Properties

14

a or 25% max + report % hydrogen

b Jet A-1 freezing point is -47°C (-53°F) maximum.

c ASTM D1655 permits retesting at 245°C.

d

 Different test method. Correlation with D 3241 (JFTOT) being established.

e Required if hydrotreated

f

 If conductivity improver is used

* Flash point by D 56 (Tag)

** Flash point by D 93 (PM)

6.2 The Manufacture of Jet Fuel

Generally in the US, the system to produce and consume petroleum products is well

balanced. This actually is an operational constraint because there is relatively little

storage capacity for refined products built into the distribution system. The U.S. refinery

system is optimized to produce a large amount of motor gasoline and smaller amounts of

“No. 2 fuels” (diesel fuel/heating oil) and “No. 1 fuels” (jet fuel, No. 1 diesel fuel and

No. 1 fuel oil).

The production of petroleum products is a complex process. Some of the complexity of

the system is retained in this overview, despite the temptation to simplify, because the

impact of jet fuel specification changes can only be appreciated with some knowledge of

the complexity of the production system.

6.2.1 Conventional Processes

6.2.1.1 The Crude Unit

Petroleum products originate from crude oil. There is no such thing as a “typical” crude

oil. All crude oils are unique mixes of many different chemical compounds. An

important variable of crude oils is the yield of light products (gasoline, No. 1 fuels, and

No. 2 fuels) that they can produce when distilled. The demand for a crude oil generally

correlates with the yield of light products that can be produced from it. Crude oil is

processed into petroleum products at refineries. Refineries vary greatly in complexity.

The simplest refinery consists of only an atmospheric crude distillation unit. Most

refineries, however, also have a vacuum distillation unit in which case the units, together,

are known as the crude unit (Section 6.2, Figure 1.)
Report of Task Group 6/7 on Fuel Properties

15

Gas

Gasoline

Kerosene

Gas Oil

Crude Heavy Vacuum

Gas Oil

Vacuum Residue

Light Vacuum

Gas Oil

Atmospheric Distillation Vacuum Distillation

Section 6.2 Figure 1. Schematic Diagram of a Crude Unit.

The crude unit separates crude oil into various fractions (or streams) by distillation. The

typical streams produced from a crude unit are:

Stream Typical Boiling Range

°F °C

Finished Products or Disposition

Gas <100 <38 Liquefied Petroleum Gas

Gasoline 100 – 400 38 – 205 Gasoline/Naphtha

Kerosene 300 – 500 150 – 260 Jet Fuel, No. 1 Diesel, No. 1 Fuel Oil

Gas Oil 400 – 650 205 – 345 Diesel Fuel, No. 2 Fuel Oil, Heating Oil, Cracker Feed

Vacuum Gas Oil 600 – 1000 315 – 540 Lube, Cracker Feed

Residue >1000 >540 Asphalt, Coker Feed

According to the API/NPRA Aviation Fuel Properties Survey (Appendix 1), 78% of the

capacity to make jet fuel in the U.S. is production from crude units.

In operating a crude unit there are basically only three parameters that can be adjusted to

influence the yield of jet fuel:

1. The selection of crude oil(s) processed.

2. The front end cut point (lower end of boiling range) of the jet fuel stream (to trade off

with naphtha yield).

3. The back end cut point (upper end of boiling range) of the jet fuel stream (to trade off

with diesel fuel yield).

Jet fuel is generally the most highly specified fuel (ASTM D1655 in the U.S) that a

refiner makes. The flash point specification limits the amount of naphtha that can be

incorporated into jet fuel. The aromatics, smoke point, naphthalenes, freeze point, and

viscosity specifications often constrain the back end cut point of jet fuel.
Report of Task Group 6/7 on Fuel Properties

16

The challenge facing the operator of a simple refinery in reacting to flash point

specification changes is illustrated by considering jet fuel yield changes from a common

crude oil. With this light crude about half the jet fuel yield is lost at 140°F (60°C) flash

point versus the current specification. The following table was prepared assuming

perfect distillation, and a release limit 8°F (4.4°C) above the specification minimum. It

shows that the light crude yield loss would be:

Flash Point Specification, °F (°C) 100 (38) 120 (49) 140 (60)

Initial Boiling Point, °F (°C) 260 (127) 302 (150) 353 (178)

End Point, °F (°C) 555 (291) 538 (281) 501 (261)

Yield Loss, % 0 19 48

Freeze Point, °F (°C) -40 (-40) -40 (-40) -40 (-40)

Flash Point, °F(°C) 108 (42) 128 (53) 148 (64)

Note that for crudes, such as this, where jet fuel yield is constrained by freeze point, jet

fuel yield is lost both at the front end (increased initial boiling point to meet flash point)

and the back end (reduced end point). To understand this, it is necessary to appreciate

that jet fuel distilled from crude oil usually contains a small but significant amount of

higher boiling straight-chain paraffin molecules. When the fuel is cooled to low

temperatures, these paraffin molecules can associate to form wax crystals. To avoid the

possibility of fuel flow problems, a freeze point specification is included in ASTM

D1655 to ensure that wax crystals do not form at fuel temperatures normally encountered

during aviation operations. The lower boiling portions of jet fuel are effective solvents

for dissolving wax crystals. As the initial boiling point of a jet fuel is increased (to

reduce flash point), solvency for wax crystals is lost. This requires that the end point of

the fuel be reduced to remove the straight-chain paraffin molecules that can form wax so

that the fuel can meet the freeze point specification.

In reality, crude units do not provide perfect distillation. Capital for upgrading the

refineries is required to improve stripping to sharpen the cut point between the naphtha

and jet fuel streams.

6.2.1.2 Jet Fuel Hydrotreating/Hydrodesulfurization

Most refineries have one or more units to “finish” jet fuel. Kerosene from the crude unit

may, depending upon crude sources, contain too much sulfur and/or mercaptan sulfur (RSH) to meet specifications. A common unit that removes both forms of sulfur from jet

fuel is the catalytic hydrotreater. In this unit, jet fuel is treated with hydrogen at

moderately high pressure (200-800 psi) and temperature (500-700°F, 260-370°C) in the

presence of a metal catalyst to reduce sulfur and remove it from the fuel.
Report of Task Group 6/7 on Fuel Properties

17

6.2.1.3 Merox Process

An alternative process often used for finishing jet fuel that has acceptable sulfur content

but high mercaptan sulfur is the Merox process. The Merox process converts mercaptans

to disulfides by the following oxidation reaction:

2 RSH + 1⁄2 O2 Ë RSSR + H2O

6.2.1.4 High Pressure Hydrotreating/Hydrocracking

According to the API/NPRA Aviation Fuel Properties Survey (Appendix 1), 22% of the

capacity to make jet fuel in the U.S. is found in hydrocracking units. Hydrocracker units

(Section 6.2, Figure 2) are used in complex refineries to convert low-value petroleum

fractions into valuable light components by breaking large, high boiling molecules, into

smaller molecules. The large molecules are cracked by the action of a catalyst at very

high temperature (600-800°F, 315-425°C) in the presence of very high pressure (up to

3000 psi) hydrogen. The operating conditions are such that hydrogen adds to unsaturated

(cracked) molecules to prevent the formation of coke that would deactivate the catalyst.

Hydrocrackers produce good quality jet fuel in terms of aromatics content, smoke point,

and oxidative thermal stability.

Hydrocrackers units are expensive to install and operate because they use hydrogen gas at

very high pressure and temperature. The expense arises both from the unit

construction/installation (driven by the cost of the large, high-pressure vessel and the

hydrogen compressors) and operation (cost of hydrogen and energy to compress it).

Because of their high cost, many U.S. refineries and a large proportion of the refineries

outside of the U.S. do not have hydrocracking units.

Hydrocracking is not a means to tailor molecules to any required form: increased jet fuel

flash point specifications are expected to reduce jet fuel yields from existing

hydrocrackers by the same mechanisms as crude unit yield losses described above. Note

that this is seen in the API survey where refineries both with and without hydrocrackers

predict similar jet fuel yield losses. Hydrocracker operators have some (limited) ability

to tune the mix of products produced by the unit. Typical parameters are hydrocracking

severity (function of temperature and hydrogen pressure) and recycle (proportion of

product streams fed back into the hydrocracker). For example, some hydrocracker units

are operated to recycle diesel fuel to extinction so that gasoline and jet fuel yields are

enhanced and diesel fuel production is eliminated. A disadvantage of increased severity

and recycle-to-extinction is that both strategies tend to increase the yield of gaseous

products that have relatively little value versus light products.
Report of Task Group 6/7 on Fuel Properties

18

Jet Fuel

Naphtha

Butanes

Fuel Gas

Hydrogen

Gas Oil

and/or

Vacuum

Gas Oil

Hy

dr

oc

ra

ck

er

St

ag

e

1

Hy

dr

oc

ra

ck

er

St

ag

e

2

H2/Oil

Separator H2/Oil

Separator

Stripper Fractionator

Section 6.2 Figure 2. Schematic Diagram of a Two-Stage Hydrocracker

1st Stage

2000-3000 psig

650-800°F

2nd Stage

1500-2000 psig

540-750°F

Lt Gasolline

Recycle

6.2.1.5 Catalytic Cracking/Thermal Cracking

Catalytic and thermal cracking units are often found in complex refineries. There are

many variations in the way that these processes are implemented in various refineries

including:

• FCC (Fluidized Catalytic Cracker)

• Delayed Coker

• Visbreaker

These units use high temperature, with catalyst in the case of FCC, to crack large

molecules to light products. The units do not use high hydrogen pressure so cracked

products are relatively high in unsaturated compounds.

This provides high octane quality in the gasoline produced but most of the product

produced in the boiling range compatible with No. 1 and No. 2 fuels is used for diesel

fuel or is used as feed to hydrocracker units. In principle thermally or catalytically

cracked streams boiling in the No. 1 fuel range could be hydrotreated to stabilize them

and then blended into jet fuel. This is not usually done for several reasons. Some of the

streams (FCC distillates, for example) contain so much aromatics that only a very small

amount can be blended into jet fuel before exceeding D1655 aromatics and/or smoke

point specifications. The streams from these processes are more difficult to hydrotreat

and cause operational problems in the jet fuel hydrotreater operation. Further, if

hydrotreating is not done properly, the fuel can have poor stability performance despite

meeting specifications. With sufficient incentive, refiners having these streams might use

them to increase jet fuel yield. Note that if this type of blending were done, many more
Report of Task Group 6/7 on Fuel Properties

19

batches of jet fuel pushing the aromatics and/or smoke point specifications would be

produced than currently occur.

6.2.2 Refinery Configuration Issues

Existing refineries have specific processing units that may constrain their upgrade path.

For example, if a refinery has an FCC unit to upgrade gas oil and/or vacuum gas oil, the

refinery is unlikely to add a new hydrocracker unit and mothball the FCC unit.

6.2.3 Advanced Processes for Jet Fuel Production

6.2.3.1 Aromatics Saturation of Cracked or Aromatic Streams

With sufficient incentive, a refiner might choose to install a new high-pressure

hydrogenation unit to saturate the aromatics and olefins in thermally or catalytically

cracked streams boiling in the No. 1 fuel range. This would tend to increase the content

of naphthenes in jet fuel. Increased naphthenes in jet fuel are not expected to cause

problems but equipment/engine builders need to confirm this before widespread

implementation. The aromatic saturation process can also be employed to increase jet

fuel yields from aromatic crude oils.

6.2.3.2 Jet Fuel Synthesis by Fischer-Tropsch Chemistry

Kerosene from Fischer-Tropsch synthesis will be used to enhance jet fuel production in

South Africa. Fischer-Tropsch chemistry produces pure paraffins (after hydrotreating to

remove oxygenates) from synthesis gas (made from natural gas or coal). This kerosene is

so low in aromatics that specifications require that it be blended with conventionally

produced streams to avoid problems with seal shrinkage. Furthermore, specification

changes have been proposed to define a lubricity and minimum aromatics requirement.

Blending also helps to improve the poor lubricity performance of this kerosene. The

production of blending streams for jet fuel by Fischer-Tropsch synthesis contributes little

to jet fuel production on a world-wide basis because Fischer-Tropsch processing is

generally more expensive than conventional processing.

6.2.4 Experimental Processes for Jet Fuel Production

The following processes have not been used commercially for jet fuel production and are

not expected to contribute to jet fuel production in the near term. They are included here

for the sake of completeness.

6.2.4.1 Catalytic Dewaxing

Catalytic dewaxing is not used commercially for jet fuel production. Catalytic dewaxing

was developed and commercially implemented to improve the low temperature

performance of diesel fuel. It could be adapted and installed in refineries to increase jet

fuel yield. The use of this processing would permit many crudes to be distilled to higher

end points resulting in raw kerosene streams failing jet fuel freeze point specifications.
Report of Task Group 6/7 on Fuel Properties

20

Catalytic dewaxing could then be applied to the kerosenes to bring the freeze point of the

finished fuel into compliance with the specification.

Catalytic dewaxing works by selectively removing the straight-chain paraffin molecules

that form wax. Catalytic dewaxing probably will not provide a significant increase in jet

fuel yield from crude oils where yield is constrained by smoke point instead of freeze

point.

6.2.4.2 Jet Fuel Synthesis by Alkylation

Alkylation is not used commercially to produce jet fuel. Alkylation units are used by

refiners to make high octane, non-aromatic gasoline and aviation gasoline from I-butane

and olefins (butenes, or mixtures of butenes with propylene or amylenes) via acid

catalysis. Refiners use the process because it converts gaseous by-products to valuable

gasoline. In principle, it is possible to employ alkylation to produce jet fuel-range

molecules. This type of processing might play a role in jet fuel production if incentives

become large enough, but significant process development and refinery capital

investment would be required before commercialization. An even greater amount of

work should be done to ensure that the resulting jet fuel is suitable for aviation

operations. In particular, any impact of impurities arising from the acid catalyst would

need to be known and judged acceptable by equipment/engine manufacturers.

6.3 Transportation from Refinery Gate to Airport

Jet fuel leaving the shipping tank in a refinery is generally destined for a terminal which

is a distribution center for more local deliveries. The fuel can travel by water, pipeline,

rail or road, but almost always in large volumes. In the U. S. most jet fuel goes to

terminals by large common carrier pipelines which are both multi-product and fungible

in nature. These lines carry all distillate products, from gasoline to diesel fuel and heating

oil and each product grade contains products from numerous shippers, all meeting the

same specification (“fungible product”). Product grades follow each other with no

physical separation and individual product quality is maintained by using very large

tenders and minimizing inter-product mixing by turbulent flow in the pipeline. In

addition, pipelines often add a shipping margin on critical properties. Additives in all

products are carefully controlled to avoid cross-contamination. Mixed product or

interface is minimized by cutting the higher quality product into the lower quality

wherever possible. Because jet fuel is in contact with gasoline and/or diesel fuel, care

must be taken to prevent jet fuel flash point decreases through gasoline mixing and

thermal stability and freezing points deterioration by diesel or heating oil addition. An

additional U. S. problem is the presence of dyed high sulfur diesel and heating oil which

cannot be allowed to mix with jet fuel.

In much of the rest of the world jet fuel is most likely to be delivered by pipelines or

ocean tankers. These ships may carry jet fuel in dedicated compartments or may depend

on cleaning and careful product sequence to operate as multi-product vessels. Because

batches are smaller, supplier identity is usually maintained. While commercial U. S. jet

fuel moves by rail cars only in Alaska, such transport is common elsewhere. Road
Report of Task Group 6/7 on Fuel Properties

21

transport to terminals is used only where distances are short. Product is usually unfiltered

until it reaches the terminal.

During terminal to airport transport most jet fuel is moved by single product means.

Some pipelines are fungible and carry only jet fuel. Road transports are segregated by

supplier and tend to be restricted to jet fuel. Wherever possible, barges carry only jet fuel

because of cleaning difficulties. In this portion of the system much of the equipment is

internally coated to minimize contamination. Product is always filtered when leaving the

terminal.

On airports the fuel may travel from storage to the aircraft by special trucks equipped

with their own pumps (“fuelers”) or it may move underground to loading gates through

pressurized piping (“hydrant system”). The fuel is always filtered into and out of storage

and again into aircraft. Water and solid contaminants are constantly removed to furnish

clean and dry product to the aircraft. Product at airports is normally commingled among

suppliers, but some airports may have single suppliers, thereby amplifying the effects of

any property changes.

A major difference between the U. S and the rest of the world is the fuel custody on the

airport. In the U. S., custody is transferred at the airport boundary and the fuel on the

airport belongs to the airline. Generally, outside the U. S. the fuel supplier maintains

ownership and handles fuel up to the aircraft skin. Because the responsibility for quality

control is with the owner, U. S. airport quality controls rests with the airlines, while

elsewhere the fuel suppliers are responsible.

6.4 Aircraft Fuel System Design

The major components of a typical commercial air transport fuel system are (1) vented

tanks using primarily the wing box, (2) an engine fuel feed and transfer system, and (3) a

fuel quantity measurement and indication system. Fuel tanks are usually located within

the wing box of the airplane. A minimum of one tank is required for each engine. For

example, on a twin engine aircraft, there is at least one tank located in each wing of the

aircraft. If the aircraft size and range require additional fuel capacity, then the center

wing box is designed to hold fuel. On a four engine aircraft there are two main tanks in

each wing with additional capacity provided by the center tank. For long-range aircraft,

fuel can be stored in reserve tanks also located in the wings, in the horizontal stabilizer,

and occasionally in body tanks. All tanks (except body tanks) are integral with aircraft

structure and are sealed on the inside to eliminate leaks.

The tanks are vented to the atmosphere such that there is at least one open vent port for

each tank under all conditions. The vent system maintains inside tank pressure at near

ambient pressure by allowing airflow into and out of the tanks during refueling, fuel use,

and during climb and descent. The vent system is designed not to exceed the pressure

limits for tanks.
Report of Task Group 6/7 on Fuel Properties

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Tanks are designed to minimize trapped fuel and a sump (drain) is provided in each tank

to collect water and particles of debris. Most large aircraft have continuously operating

water scavenging (removal) system or the sumps are manually drained regularly. An

independent fuel feed system is required for each engine with a capability to cross-feed to

the other engine(s) when necessary. A typical engine fuel feed system consists of

electrically driven boost pumps in the tanks, fuel lines, valves and fittings. In addition,

the engine has the capability to draw fuel from the tank if for some reason the boost

pumps become inoperative. An independent fuel feed system is also provided for the

auxiliary power unit (APU). The system is designed for rapid pressure fueling and for

defueling. Some aircraft are designed to jettison fuel overboard if it becomes necessary

to land before enough fuel is used to reduce aircraft weight in order to satisfy landing

requirements.

The system design philosophy, along with experience gained in fleet operation, has

evolved into current design standards. Each aircraft is certified to fly on specified fuel

types. These generic fuel types include the kerosene fuels  Jet A/A-1, JP-8, JP-5, &

TS-1, and wide-cut fuels  JP-4 & Jet B. However, some of the newer airplane models

are not certified to use any wide-cut fuel. Flight tests are conducted under extreme

operating conditions to ensure that the fuel system as designed will provide the specified

fuel to the engine without interruption.

6.5 Current Jet Fuel Demand

Jet fuels delivered to the airlines conform to the property requirements identified in one

or more of the many different jet fuel specifications used throughout the world. The

majority of these fuels can be grouped into three main types of kerosene fuels. They are

Jet A, Jet A-1, and TS-1. There is a very small amount of wide-cut fuel (JP-4 and Jet B)

used by commercial airlines in Northern Canada and at some remote locations worldwide

that also serve as military airfields.

About 38% of the jet fuel is up-lifted in the United States. (See Table 1) U. S.

consumption together with Western Europe accounts for 57% of the world jet fuel

demand. It is estimated that a change in jet fuel flash point, which may be implemented

in the U.S. and Europe, would prompt similar changes in other jet fuel specifications

effectively covering over 70% of the delivered jet fuel. Today, only about 7% of all jet

fuel manufactured for the worldwide fleet has a flash point less than 100oF(38oC). These

data1 are estimates only, since details are not available on consumption of jet fuel by

type.

 

1

Section 6.5 Ref. 1. Derived from the International Energy Annual, DOE/EIA-0219(96), February 1998.
Report of Task Group 6/7 on Fuel Properties

23

Jet A Jet A-1 TS-1

U. S. 1,514

Other North America 65 66

Central & South America 146

Western Europe 771

Africa 125

Middle East 154

Former Soviet Union 267

Eastern Europe 25

China 86 20

Other Far East 753

Total 1,579 2,126 287

Section 6.5, Table 1—Approximate Consumption of Jet Fuel in 1995

(thousands of barrels per day; barrel = 42 U.S. gallons)

6.6 Demand for Other Distillates

Oil refineries produce a wide spectrum of products from crude oil, ranging from

Liquefied Petroleum Gas (LPG) to Bitumen. The demand for each of these products

varies from region to region depending on local circumstances. For example, in some

regions fuel oil is used for power generation and kerosene is a domestic cooking fuel, in

others power generation and domestic cooking are both fueled by natural gas.

One of the most striking differences is gasoline/gas oil balance between North America

and Europe, illustrated in Figure 1. North America is primarily a gasoline economy and

refineries are configured to maximize gasoline production. Diesel/gas oil demand and

production is relatively low. In Europe, the demand for gasoline and gas oil is much more

balanced. This European balance is typical of most regions of the world. In this context,

North America has the unusual demand pattern.

One of the consequences of this difference is that, in Europe and the rest of the world,

there is real competition between jet fuel and gas oil/diesel for the distillate fraction of

the barrel in addition to the more constrained freeze point of Jet A-1.
Report of Task Group 6/7 on Fuel Properties

24

0%

20%

40%

60%

80%

100%

North

America

North

West

Europe

Med

Europe

Latin

America

FSU Eastern

Europe

Africa East of

Suez

LPG

Naphtha

Gasoline

Jet Fuel

Kerosene

Auto

Diesel

Other

Gasoil

Fuel Oil

Others

9.0

7.4 5.4

4.1

6.0

4.0 7.4 5.6

4.5 6.4

Section 6.6, Figure 1--Variation in the Demand for Products Across

Different Regions of the World

This dramatic difference in cut of the barrel demands between North America and Europe

is one of the main reasons for the different impacts on jet fuel availability predicted for

changes in flash point.

It should also be noted that forthcoming legislative changes for diesel fuel in Europe are

likely to raise the competition for kerosene molecules as diesel fuels are required by

legislation to decrease and more kerosene will be required to meet the diesel fuel

demand.

6.7 Military Experiences

During the most recent fiscal year (FY 1997, ending 30 September 1997), the Defense

Energy Support Center (DESC, formerly the Defense Fuel Supply Center, or DFSC)

purchased worldwide, on behalf of the U.S. government (mostly the military), 82.8

million barrels (MMB) of jet fuels, or about 227 thousand barrels per day (MBD). These

purchase volumes are on the same order of magnitude as the largest airlines. Of these

volumes, about 216MBD (95.5 percent) were purchased “in bulk” – mostly large

pipeline, tanker, or barge lots lifted directly from a refinery or large terminal. Worldwide

“intoplane” volumes, those delivered directly by vendors to the wings of aircraft being

refueled at commercial airports, totaled about 10MBD. While military fuel use has

declined markedly with the current defense downsizing (down 42.1 percent since FY

1988), it is expected to be level near current levels for the next several years.
Report of Task Group 6/7 on Fuel Properties

25

U.S. military jet fuels are almost entirely kerosene-based fuels. Of the FY 1997 volumes,

only 2.8MBD, or 1.2 percent of the total, was wide cut JP-4 fuel (similar to commercial

Jet B fuel). Bulk JP-8 accounted for 165MBD (72.6 percent) of total volumes. JP-8 is

very similar to the commercial Jet A-1 fuel, which is the predominant kerojet fuel outside

of North America. It is used by land-based U.S. military aircraft – Air Force and Army

aircraft, plus some Navy and Marine Corps aircraft that do not routinely visit aircraft

carriers during their missions. Intoplane volumes (4.5 percent of the total) are almost

entirely Jet A-1 or Jet A, the commercial fuel most commonly sold in the United States.

The remaining 49.1MBD (21.7 percent) of U.S. military jet fuel volumes are bulk JP-5, a

high flash point kerojet fuel for the Navy and Marine Corps

Of U.S. military bulk fuel volumes, 72.3 percent are purchased in the United States.

Given that the military jet fuels do not meet U.S. domestic commercial specifications,

they cannot be handled fungibly with commercial product. Thus, they must often be

custom manufactured, and segregated from commercial fuels – whether at the refinery or

throughout the downstream distribution system. Overseas, the situation is less

complicated, because JP-8 is essentially Jet A-1 plus an additive package (which can

often be injected downstream of the refinery). Some U.S. domestic refiners who are U.S.

military suppliers are understood to make their commercial fuel to the more restrictive

military specifications in order to rationalize their on-site operations. Despite the

specification differences, The DESC has been able to procure JP-8 in the United States at

prices which are approximately equal to domestic Jet A prices. The more restrictive JP-5

specification results in fewer suppliers and prices that run some 1 to 3 cents per gallon

above commercial jet fuel on the U.S. Gulf Coast. It should be noted that JP-5 is a very

low volume specialty project that accounts for about 3 percent of U.S. jet fuel production.

Throughout most of the post-World War Two period, most land-based U.S. turbine

powered military aircraft have used the wide cut JP-4 fuel, which was developed in 1951.

The U.S. Air Force developed the JP-8 specification in 1972 in response to their combat

experience in Vietnam. The new fuel specification promised better survivability in

combat and greater safety in operations and handling. Land-based U.S. military aircraft

have been interoperable among JP-4, JP-5, and JP-8 since 1976.

The worldwide conversion of land-based U.S. military aircraft took place in several

phases from 1979 through 1995. The impending conversion of domestic military

requirements was announced in November 1991, and carried out in a regional phase-in

from October 1993 through October 1995. Because the domestic conversion involved

some 200 MBD of JP-4 requirements (about 15 percent of U.S. jet fuel consumption at

the time), the military anticipated problems with product availability, and cost increases

of some 5 to 10 cents per gallon over JP-4.

The U.S. domestic conversion was completed successfully in 1995, with actual product

costs only 2 to 3 cents above JP-4 prices. The successful conversion was due to several

factors: 1) projected JP-8 requirements declined due to force downsizing, 2) a U.S.

recession reduced overall U.S. jet fuel consumption, 3) aircraft operating efficiency
Report of Task Group 6/7 on Fuel Properties

26

continued to improve, and 4) the U.S. refining industry had leadtime of 2 to 4 years to

prepare for the change.

The Air Force experienced some operational impacts as a result of conversion from JP-4

to JP-8. The two most significant issues were (1) efficient operation of older

aircraft/engines, and (2) seal/sealant material leaks. As a result of the changes in

viscosity and volatility between JP-4 and JP-8 the Air Force did experience some

operational difficulties with specific older model aircraft and engines. This was

particularly true in cold weather locations. Some aircraft and engines experienced cold

weather start difficulties and lost some altitude relight capability. Most of these issues

were addressed by changes to fuel scheduling systems, fuel controls, nozzles and burners.

The small volumes of JP-4 that continue to be procured are in response to these lingering,

minor issues.

The Air Force also experienced a widespread problem with seals and sealant materials

that were related to differences in aromatic content between JP-4 and JP-8. This was

predominately resolved by changing “O” rings. Although it did require maintenance

action to change the seals this was a one-time issue and not a major impediment to the

conversion. In addition to these issues related to the JP-4/JP-8 conversion, DESC and the

services have experienced quality problems with kerosene-based jet fuels, which are

related to changes in refinery processes and feedstocks. In general, these issues have

been resolved on an individual basis.
Report of Task Group 6/7 on Fuel Properties

27

7.0 DESIGN ALTERNATIVES

Task Group 6/7 examined the impact of a range of minimum flash points as design

alternatives.

Other design alternatives would be the consideration of other technologies, or flash point

changes in combination with other technologies. It is beyond the scope the Task Group

6/7 to make such comparisons.
Report of Task Group 6/7 on Fuel Properties

28

8.0 INSTALLATION/RETROFIT REQUIREMENTS

8.1 Fuel Phase-in Requirements

Major fuel specification changes (such as flash point) require large lead times for

refineries to implement the necessary investments if they should decide to do so and

continue to produce the fuel and greater lead time for refiners to make potential

investments to produce the fuel. Typically, refineries need four to five years to complete

major capital projects, which includes design and planning, obtaining the necessary

permits, construction, and start up. For example, Federal reformulated gasoline was

implemented in 1995 (five years after the Clean Air Act mandating RFG was passed). In

addition, a transition period of three months should be considered to allow the new fuels

to replace the current fuels in the supply and distribution system.

8.2 Retrofit Requirements

If the fuel flash point is increased over current levels, addition of a fuel heater at the

aircraft Auxiliary Power Unit (APU) inlet would be required to maintain the fuel

temperature above that corresponding to a maximum viscosity of 12 centistoke, to ensure

reliable starting for all ambient conditions. Section 8.2.3.1 provides a detailed

explanation of the effects of a fuel flash point increase on APU cold and altitude starting.

The cost impact of an APU fuel heater is provided in Section 12.6.2.

Approximately 24 months would be required for development and qualification of a

direct current (DC) powered APU fuel heater with BITE (Built In Test Equipment) prior

to delivery to the aircraft manufacturer. An additional 12 to 24 months would be required

to incorporate the fuel heater in the field. There would be an increase of approximately 4

lb. in APU weight. The fuel heater could be run off the APU battery in-flight, using the

existing battery charger powered by the main engine generators.

Additional time and effort would be required to complete any aircraft modifications or

flight-testing required. Aircraft changes that may be required include wiring from the

APU to the electronic control unit (usually located in a different compartment),

modifications to the flight deck display, modifications to the APU battery or charger,

modifications to the main engine generators, modifications to aircraft operational

procedures, and any airplane manual revisions.

Additional development time, additional weight, and additional aircraft modifications

would be required if an AC powered fuel heater were employed.
Report of Task Group 6/7 on Fuel Properties

29

9.0 TECHNICAL DATA

9.1 Flash Point

9.1.1 Tank Ullage Flammability

Jet fuel has one basic purpose, to burn and release large quantities of heat. Ideally this

process would occur only in the engine’s combustion system, but jet fuel characteristics

can also create a combustible mixture in tankage vapor space or ullage under certain

conditions. Three ingredients are needed to cause a fire: fuel vapors, air (oxygen) in

proper proportion and an ignition source. It therefore makes sense to first discuss fuel

evaporation and then its impact on flammability.

The rate of evaporation and the concentration of evaporated fuel in ullage depend on fuel

vapor pressure, fuel temperature and air pressure and temperature. Of these parameters

fuel vapor pressure is the most difficult to precisely establish because jet fuel is a

complex mixture of hydrocarbons whose vapor pressure is the sum of the partial

pressures of all the constituents. Evaporation alters the composition of the fuel and the

vapor pressure decreases with the quantity of fuel evaporated. A relatively simple test to

measure the vapor pressure of gasoline exists as ASTM D 323, but it only approximates

the true vapor pressure of fuel. Vapor pressure measurements of kerosene by this method

are further unreliable because they are very near the lower detectable limit of the method.

Very specialized equipment is required to measure true jet fuel vapor pressure.

Fuel volatility or its tendency to evaporate, is therefore controlled by other, more

empirical means. In the refinery distillate products are separated by boiling range, which

is measured by a simple distillation. In this method (ASTM Test Method D 86) product

is boiled off, condensed and recovered, while vapor temperature is monitored. The

resultant temperature vs. per cent recovered serves as a general characterization, but the

test method does not account for up to 1.5% of the most volatile products which are not

condensed. However, these constituents determine vapor flammability, so they are

characterized by determining the temperature at which the vapor first becomes

flammable. This temperature is called the flash point. Details and limitations of flash

point methods are discussed in the remainder of this section.

Relating jet fuel characteristics to ullage flammability is complex. Aside from the

imprecise characterization of volatility, ullage vapor concentrations do not reach

equilibrium when fuel is withdrawn from tanks vented to atmosphere. Air flows out of

the tanks as air pressure decreases during climb, and dissolved gases can evolve from the

fuel. Possible tank agitation resulting in sloshing or misting adds to the complexity. In

the simplest test case, a tank is partially filled with fuel and the fuel is allowed to

evaporate as temperature is increased in steps at constant pressure. In letting all

conditions come to equilibrium at each temperature, a temperature is reached when

enough fuel is evaporated to first form a flammable mixture. This temperature is called

the lower flammability limit (LFL) or lean limit. As the system temperature is increased,

the vapor space remains flammable until so much fuel is evaporated that there is
Report of Task Group 6/7 on Fuel Properties

30

insufficient oxygen to permit combustion. This temperature is the upper flammable limit

(UFL) or rich limit. Conducting these experiments at reduced air pressures – increasing

altitudes – results in curves such as are contained in Figure 1(1). Because of decreasing air

density less fuel vapor is needed at altitude to maintain a constant fuel/air ratio and a

lower system temperature will maintain the LFL.

 Figure 1 also illustrates the difference between different fuel grades. Adding factors such

as outgassing shifts the limits as does misting or sloshing. The large effect on

flammability limits resulting from extreme sloshing is illustrated in Figure 2.

Unfortunately this effect depends entirely upon the conditions under which the tests were

conducted and will differ greatly in real life situations. In tankage the vapor concentration

will be highest just above the liquid level and lowest at the top surface. At very low fuel

levels the non-homogeneity of fuel vapors becomes even greater because of uneven fuel

warming and the cooling effects of vertical tank members. As a result, the relationships

between existing fuel tests and tank flammability are not precise and not directly related

on a one-to-one basis. Therefore, flammability conditions can be difficult to predict. In

fact, the Executive Summary of the recently published FAA Final Report A Review of the

Flammability Hazard of Jet A Fuel Vapor in Civil Transport Aircraft Fuel Tanks

(DOT/FAA/AR-98/26) states the following:

 “In addition to finding a need for more data on the flammability of Jet A

fuel, the task group found present methods for predicting in-flight fuel

temperatures to be inadequate. The development of reliable heat transfer

models and the ability to calculate the flammability of the ullage space

in an aircraft fuel tank under different environmental and operational

conditions are in the early stages. Therefore the ability to reliably

evaluate different strategies to reduce the flammability of jet fuel in the

center wing tank of a B747 has not been proven.”
Report of Task Group 6/7 on Fuel Properties

31

0

2

4

6

8

10

12

14

16

18

20

22

24

-80 -60 -40 -20 0 20 40 60 80 100

Temperature, oC

Altitude

 m x 10-3

Av. Gas

JP-4

Jet B

Jet A

Jet A-1

JP-8

JP-5

Section 9.1.1, Figure 1--Fuels Flammability Limits vs. Altitude
Report of Task Group 6/7 on Fuel Properties

32

0

2

4

6

8

10

12

14

16

18

20

22

24

-80 -60 -40 -20 0 20 40 60 80

Temperature, oC

Altitude

m x 10-3

Dynamic

Static

JP-4

Jet B Static

Jet A

Jet A-1

JP-8

Dynamic

Section 9.1.1, Figure 2--Effect of Tank Dynamics on the Relative Flammability

Limits of Jet Fuels

9.1.2 Flash Point Methods and Significance

Liquid fuels all exhibit an equilibrium vapor pressure that is dependent on the

temperature of the fuel. As the temperature of the fuel is raised, the fuel vapor in

equilibrium with the liquid fuel reaches a sufficient concentration to ignite when mixed

with air and exposed to a strong ignition source such as a flame. The temperature of the

fuel at this point is known as the lower flash point temperature. If the temperature of the

fuel is increased, the equilibrium vapor pressure increases to a point where the air-vapor

mixture contains so much vapor that it is above the upper flammable limit for the fuel.

The temperature at which combustion will not occur is known as the upper flash point

temperature. For kerosene-based jet fuels such as Jet A and Jet A1, the relevant

temperature is the lower flash point temperature and is commonly referred to as the flash

point. This convention is used in this report.

In actual practice, the flash point is measured in several standardized pieces of apparatus.

The most reproducible are “closed” cup methods. In these methods a sample is placed in

a closed sample container and stirred. The temperature is increased at a prescribed rate.

Periodically, the vapor is exposed to a flame and observation of whether combustion

occurs is made. The lowest temperature at which the vapor ignites with a distinct flash is

taken as the flash point. This observed measurement is then corrected for pressure by the

equation:
Report of Task Group 6/7 on Fuel Properties

33

Flash Point (oF) = Observed Flash Point (oF) +0.06 [760-Ambient Pressure (mm Hg)]

While the methods all measure the Flash point, the actual value measured and the test

reproducibility can differ. There are four closed cup methods that are used commonly in

aviation fuel specifications. These are shown in Section 9.1.1, Table 2. ”Repeatability” is

the maximum expected difference in two test results by the same operator and

instrument; “Reproducibility” is the maximum expected difference in two test results by

different operators in different laboratories. At the current flash point specification the

reproducibility and repeatability are given in Section 9.1.1, Table 2. Section 9.1.1,

Table 3 gives the flash point as measured by each apparatus for n-decane and nundecane. As seen from this table, slightly different results are obtained with each

method. In this study, flash point results are measured or adjusted to be the same as

measured by ASTM D56. In specifications, ASTM D 1655, the commercial specification,

uses D56 as the referee method, MIL-T-5624N and MIL-T-83133D, the United States

Military Specifications use D 93 as the referee method, and DEFStan 91-91, the British

specification uses IP 170 as the referee method. Care needs to be taken when reporting

data to understand which method was used.

Method Title Repeatability for

100oF &140oF Fl.Pt.

Reproducibility

100oF &140oF

Fl.Pt.

ASTM D 56 Standard Test Method for Flash

Point by Tag Closed Tester

2.0oF/2.0oF 8oF/8oF

ASTM D 93 Standard Test Method for Flash

Point by Pensky-Martens Closed

Cup Tester

2.4oF/3.8oF 5.1oF/8oF

ASTM

D 3828

Standard Test Methods for Flash

Point by Small Scale Closed

Tester

0.9oF/0.9oF 3.7oF/3.7oF

ISO 170 Petroleum Products –

 Determination of Flash Point –

Abel Closed Cup Method

1.8oF 2.7oF

Section 9.1.2, Table 1–Closed Cup Flash Point Temperatures
Report of Task Group 6/7 on Fuel Properties

34

Method Flash Point

oC

n-Decane n-undecane

D56 50.9 67.1

D93 52.8 68.9

D 3828 49.8 65.9

IP 170 48.9a65.1a

a

 Result inferred from DefStan 91-91 Specification Limits; Calibration procedure

not listed in standard

Section 9.1.2, Table 2–Flash Point Differences in Test Methods

The flash point results can vary substantially from the actual lower flammability limit.

While a definite difference has not been defined, ignition as much at 8-10oF below the

actual flash point have been observed. Actual ignition of fuel vapors can be affected by

factors such as:

• Direction of flame propagation – vertical upward flame requires less hydrocarbon to

ignite than downward propagation induced in these methods.

• Non-equilibrium effects -- vapor concentration may not be uniform throughout a

container, and time is needed for liquid to evaporate or for vapor condensation as

conditions change.

• The ullage to liquid volume ratio -- the amount of hydrocarbon vapor differs and

hence composition of the vapors can be different- this effect is particularly significant

for fuels such as kerosene, which are mixtures of hydrocarbons with different

volatility, not pure compounds.

• Liquid mass transfer --can determine the rate of vaporization and other diffusional

effects which can have an effect on the flash

• Mixing in ullage space -- can determine when ignition can occur.

Thus, while the flash point adjusted for actual conditions can be used as a surrogate for

the temperature at the lower flammability temperature, it should be understood that actual

ignition can occur several degrees above or below this value.

While slightly different results can be obtained from the several test methods which are

commonly used, these differences are small compared to the range of flash points found

for kerosene as sold in the marketplace. Practices established for use and application

must generally be based on an expectation that kerosene has the minimum allowed flash

point; survey data shows that is improbable. It might be advisable to harmonize on a

single method for use in all specifications, and consideration of that is underway and will
Report of Task Group 6/7 on Fuel Properties

35

likely occur if flash point requirements for jet fuel are changed to a higher minimum

value.

9.1.3 Flash Point Distributions

Flash point distributions are subject to some variation depending on the source and

timing. In this study we attempt to find a sufficiently large database which would be

meaningful, and test it where possible against other data or databases. However, because

of the nature of the data, the results are presented as numerical averages -- they have not

been weighted on a volume basis or other possible schemes. In fact, there can be

significant debate as to which average is best for this study. The numerical data presented

in this study should be sufficient to provide necessary data for further analysis.

9.1.3.1 United States Data

One of the largest readily available databases on flash points at United States Airports is

provided by measurements by the U.S. military at commercial airports. This database2

provides measurements of flash point at all contract commercial airports. These samples

were taken from a period of August 1994 to September 1996.

A summary of the data is shown in Section 9.1.3, Figure 1.

Flash Point Distribution

Flash Point (F)

frequency

90 110 130 150 170 190

0

100

200

300

400

500

600

Section 9.1.3, Figure 1--Flash Point Distribution in U.S.

Based on these data and other survey, results indicate that the average flash point in the

United States would be between 124oF and 127oF with a standard deviation of 10 to 12

o

F.

9.1.3.2 United Kingdom Defense Research Agency Flash Point Data3

The Defense Research Agency publishes survey data annually. One thousand four

hundred forty four (1444) samples were analyzed for flash point. A summary of the 1997

data is shown in Section 9.1.3, Figure 2. The mean flash point was 111.6oF with a

standard deviation of 4.5oF, when the flash point is adjusted to be equivalent to ASTM

D56.

 

2

Into Plane Contract Testing Air Force Directorate of Aerospace Fuels, Technical Division (SFT) Kelly

Air Force Base, Texas (January 15, 1997)

3 The Quality of Aviation Fuel Available in the United Kingdom Annual Survey, 1997 Defence Research

Agency, Land Systems, Fuels & Lubricants Centre (1997 - to be published)

Normal Distribution

Flash Point (F)

cumulative probability

90 110 130 150 170 190

0

0.2

0.4

0.6

0.8

1
Report of Task Group 6/7 on Fuel Properties

36

United Kingdom Flash Points, 1997

0

5

10

15

20

25

30

35

40

104 108 111 115 118 122 126 129 133 136

Flash Point (F)

Percent

0

10

20

30

40

50

60

70

80

90

100

Cumulative Percent

Section 9.1.3, Figure 2--Flash Point Data for Fuels Available in United

Kingdom

9.1.3.3 European Flash Point Distributions

The Central Europe Pipeline System4 publishes survey data annually. The data is

compiled from 15 different sources located in the Netherlands, Belgium, France, and

Germany. One thousand five hundred twenty three (1523) samples were analyzed for

flash point. A summary of the 1996 data is shown in Section 9.1.3, Figure 3. Assuming a

normal distribution, the mean flash point was 114.8oF with a standard deviation of 8.0oF,

when the flash point is adjusted to be equivalent to ASTM D56.

CEPS Flash Point

0

5

10

15

20

25

30

104 107.6 111.2 114.8 118.4 122 125.6 129.2 132.8 136.4 140 143.6 147.2 150.8 154.4 158 161.6 165.2

Flash Point (F)

Per

cen

t

0

10

20

30

40

50

60

70

80

90

100

Cu

mu

lati

ve

Per

cen

t

Section 9.1.3, Figure 3–Flash Point Distribution in Europe

 

4

 Central Europe Pipeline System Characteristics of Aviation Fuel within the CEPS 1996
Report of Task Group 6/7 on Fuel Properties

37

9.1.3.4 Average Flash Point Distribution Curve Worldwide

To simulate an average flash point distribution worldwide, the flash point distributions

from the United States, United Kingdom, and CEPS (Europe) were weighted in the

following way:

• The United States flash point distribution was weighted by the percent of jet fuel

consumed in the United States and 1/3rd the jet fuel consumption in Central and South

America. Weighting Factor = 45%

• The United Kingdom flash point distribution was weighted by the percent consumed

in the United Kingdom, the Middle East, Africa, and the Far East and 1/3rd the jet fuel

consumed in Central and South America. Weighting factor = 34%

• The CEPS flash point distribution was weighted by the percent consumed in the

Western Europe and 1/3rd the jet fuel consumed in Central and South America.

Weighting factor = 21%

Average Flash Point Distribution -- World Wide

0

5

10

15

20

25

100 110 120 130 140 150 160 170

Flash Point (F)

Percent

Section 9.1.3, Figure 4–Flash Point Distribution –Worldwide Average
Report of Task Group 6/7 on Fuel Properties

38

Lack of data precluded assignment of weights to production in Mexico, Canada, China,

and C.I.S. Thus the flash point distributions are for Jet A and Jet A-1 only. Other fuels

are not included in this averaging, but the average of 13 samples taken in Russia and the

C.I.S is 95.7 oF (35.4 oC). Based on this calculation, the distribution of worldwide flash

points is given in Section 9.1.3, Figure 4. The actual values are in Section 9.1.3, Table 1.

Flash Point Cumulative

F Percent

100 1.3

105 6.3

110 22.1

115 45.7

120 64.2

125 76.9

130 86.5

135 93.1

140 97.1

145 99.0

150 99.7

155 99.9

160 100.0

Section 9.1.3, Table 1--Flash Point Distribution – Worldwide Average

A summary of the flash points given in Section 9.1.3, Table 2.

PADD Mean Flash Point (oF) Std. Deviation (oF) # of Samples

U.S. 124.1 10.5 1497

PADD 1 127.5 10.0 446

PADD 2 126.0 9.1 405

PADD 3 120.0 11.4 357

PADD 4 123.3 10.4 109

PADD 5 ex California 119.2 8.6 91

California 121.1 8.1 86

United Kingdom 111.6 4.5 1444

Central Europe Pipeline

System

114.8 8.0 1523

Section 9.1.3, Table 2--Statistical Summary of Flash Point Data

9.1.4 Flash Point Margins

In the United States, the average value of flash point is approximately 19-27oF above the

specification limit. This is not entirely product give-away, i.e., higher flash resulting from

inefficient and/or most economical operating point for a refinery. Increasing the flash
Report of Task Group 6/7 on Fuel Properties

39

point specification will not permit producers operating above the new specification to

maintain status quo. The producer will have to increase his production limit

commensurably. Section 9.1.4, Figure 1 shows a schematic of the factors involved in

producing on-spec fuel at the airport. The components going into the flash point produced

are as follows:

• Pipeline Specification -- ................................................................................................ 8

o

F

• Test Tolerance -- ........................................................................................................ 4.9oF

• Process Control -- ......................................................................................................3-8oF

• Product Give-away -- ..................................................................................................... ??

As a check on this model, the United Kingdom data (Section 9.1.3, Figure 2) can be

examined. Here, the producers are trying to maximize middle distillate. It is highly likely

that they are attempting to optimize Jet A-1 operations. Since they do not have to meet

pipeline specifications, the flash point produced at the refinery should be 7-13oF over the

specification value. The observed average is 11.6oF -- within the estimate proposed.

Assuming product give-away is eliminated, one can make an estimate of the variance for

delivery of fuel through a pipeline. The variance is the sum of the individual variances,

i.e.,

s s 2 2= ∑ i

If one assume 95% confidence in test tolerance at airport and into pipeline as well as a 2

degree process control limit at 95% confidence limits, the standard deviation could be as

low as 4.3oF. If the pipeline maintains its requirement of specification plus test

reproducibility into pipeline the standard deviation can be as high as 5.8oF. This assumes

no product give-away.

As the flash point specification is raised, the flash point will also rise commensurately

(approximately12 - 15oF) at the refinery to assure on-spec product is delivered to the

airport in the United States. Where pipelines are not involved, i.e., where there is a single

transfer, the flash point on average can be as low as 8oF higher than the specification. The

standard deviation could be as little as 3.13oF for this case. This will result in an

additional cost to most, if not all refiners, to achieve any increase in specification.

For the purpose of this study, σ = 5.8oF for fuel consumed in the United States and 3.13oF

for fuel consumed in the rest of the world. Future changes such as the NATO pipeline

becoming a multi-product pipeline typical of the pipelines in the United States would

change the standard deviation to be more like the United States.

A final option could be to carry out multiple flash point tests at each transfer. For

example if four flash point tests were done at transfer, the reproducibility would be 4oF

rather than 8oF for a single measurement. This would reduce the standard deviation to

3.1oF for the United States and 2.7oF for the rest of the world. This case is also presented

in Section 9.1.5.
Report of Task Group 6/7 on Fuel Properties

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Section 9.1.4, Figure 1--Achieving Flash Point Specification

Versus Flash Point at Refinery

9.1.5 Flash Point Predictions

For the future, it is assumed that the manufacturer will not give product quality away.

While this assumption is inevitably true for high flash, e.g., flash points greater than 130-

140oF, the amount of give-away for lower level of flash point is debatable. It is assumed

that for the United States the standard deviation of the product will be 5.8oF and that 99%

of the product will be meet specification. The United Kingdom and European will have a

standard deviation of 3.13oF.

An average worldwide distribution was obtained by adding 45% of the United States

flash point distribution to 55% of the European flash point distribution.

The results of these calculations are shown in Section 9.1.5, Figures 2 to Section 9.1.5,

Figure 4. For the United States the flash point is 13.5oF higher than the specification, the

European is 7.4oF higher than the specification.
Report of Task Group 6/7 on Fuel Properties

41

If four flash point measurements were taken at each transfer, the mean temperature for

the United States would be about 7.4oF above the specification and worldwide would be

about 6.4oF.

Flash Point Distributions - USA

0

10

20

30

40

50

60

100 110 120 130 140 150 160 170 180 190 200

Flash Point (F)

Perfect

100F

110F

120F

130F

140F

150F

Section 9.1.5, Figure 2–Predicted Flash Point Distribution

in United States with No-Give-Away
Report of Task Group 6/7 on Fuel Properties

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Flash Point Distributions - Europe

0

10

20

30

40

50

60

100 110 120 130 140 150 160 170 180 190 200

Flash Point (F)

Percent

100F

110F

120F

130F

140F

150F

Section 9.1.5, Figure 3–Predicted Flash Point Distribution

in Europe with No-Give-Away
Report of Task Group 6/7 on Fuel Properties

43

Flash Point Distributions - Worldwide

0

10

20

30

40

50

60

100 110 120 130 140 150 160 170 180 190 200

Flash Point (F)

Percent

100F

110F

120F

130F

140F

150F

Section 9.1.5, Figure 4–Average Worldwide Predicted Flash Point

Distribution with No-Give-Away

9.1 Fuel Property Effects

9.2.1 Fuel Property Effect Predictions

9.2.1.1 Introduction

An increase in the jet fuel flash point specification can be expected to affect the

properties of jet fuel in three ways:

1. By causing refiners to modify jet fuel distillation properties in conventional refinery

processes to meet the new specification.

2. By increasing the probability that refiners will extend yield by modifying jet fuel

processing schemes. Both the greater use of conventional processing such as severe

hydrocracking and the implementation of unconventional refinery processing may

occur
Report of Task Group 6/7 on Fuel Properties

44

3. By causing significant property shifts in the jet fuel made by conventional refinery

processing in some areas that rely on unique refinery configurations or atypical crude

oils.

It is important to note that a higher flash point Jet A is a new jet fuel specification.

Experience gained with JP-5 [140°F (60°C) flash point, -51°F (-46°C) freeze point] is not

relevant because:

• JP-5 is a niche product made by few refiners (who presumably are well situated to

produce it). A fuel made in commercial quantities, where maximizing yield is an

issue, will have different properties.

• The higher freeze point [-40°F, (-40°C)] of a high flash point Jet A results in

significantly changed properties, such as higher viscosity, versus JP-5.

9.2.1.2 The Impact of Modified Distillation Properties: Jet Fuel Properties Survey

Task Group 6/7 reviewed the literature and developed a number of cases to predict the

fuel properties that would result from changes in the distillation profile if the flash point

specification were raised from 100°F (38°C) to a higher limit. A survey was conducted

where selected properties were calculated (by participants’ proprietary analysis/predictive

systems) for a number of crudes as function of flash point and freeze point. The feedback

from the various participants was collected and regressed to calculate average values.

The crude oils included in this analysis are shown in Section 9.2.1, Table 1.

1. Nigerian Light 6. Arab Light (Saudi Arabia) 11. Brent North Sea

2. Arabian Light 7. Maya (Mexico) 12. Sumatran Light Waxy

3. North Sea 8. Cano Limon (Colombia) 13. Arab Light

4. Alaska North Slope 9. Alaska North Slope 14. Mexico Maya Heavy

5. Maya 10. California LA Basin 15. Venezuela Merey Export Blend

Section 9.2.1, Table 1--Crude Oils Included in the Jet Fuel Property Survey

The crude oils were chosen to represent a broad range of those currently refined. No

effort was made to balance the selection of crudes to match the “average” slate

commercially refined to produce jet fuel. Thus, the current jet fuel pool average for any

given property is expected to be offset from the average from this study. The changes in

jet fuel properties found in this study are expected to be substantially more predictive

than average values. The changes in distillation properties are shown in Section 9.2.1,

Table 2. The non-distillation property changes are presented in Section 9.2.1, Table 3.
Report of Task Group 6/7 on Fuel Properties

45

Flash

Point

°F (°C)

Freeze

Point

°F (°C)

Change

in Flash

Point

°F (°C)

Change in

Initial

Boiling

Point

°F (°C)

Change in

10%

Boiling

Point

°F (°C)

Change in

50%

Boiling

Point

°F (°C)

Change in

90%

Boiling

Point

°F (°C)

Change in

Final

Boiling

Point

°F (°C)

120 (49) -40 (-40) 20 (11) 38 (21) 24 (13) 12 (7) -3 (-2) -14 (-8)

140 (60) -40 (-40) 40 (22) 76 (42) 49 (27) 24 (13) -7 (-4) -28 (-16)

150 (66) -40 (-40) 50 (28) 94 (52) 60 (33) 30 (17) -9 (-5) -35 (-19)

100 (38) -53 (-47) 0 (0) 8 (4) 0 (0) -15 (-8) -31 (-17) -36 (-20)

120 (49) -53 (-47) 20 (11) 65 (36) 24 (13) -3 (-2) -35 (-19) -51 (-28)

140 (60) -53 (-47) 40 (22) 123 (68) 49 (27) 9 (5) -38 (-21) -67 (-37)

150 (66) -53 (-47) 50 (28) 152 (84) 60 (33) 15 (8) -40 (-22) -15 (-8)

Section 9.2.1, Table 2--The Change in Distillation Properties versus Base

from the Jet Fuel Properties Survey

Flash

Point

°F (°C)

Freeze

Point

°F (°C)

Change

in Freeze

Point

°F (°C)

Change in

Viscosity at

–4°F (-20°C)

(centistoke)

Change in

Smoke

Point

(mm)

Change in

Density

(kg/m3)

Change in

Aromatics

Contents

(%)

Change in

Heat of

Combustion

(mJ/kg)

120 (49) -40 (-40) 0 (0) 0.6 -1.4 8 0.4 0.0

140 (60) -40 (-40) 0 (0) 1.2 -2.8 17 0.7 -0.1

150 (66) -40 (-40) 0 (0) 1.5 -3.4 21 0.9 -0.1

100 (38) -53 (-47) -13 (-7) -1.1 0.7 -7 0.0 0.1

120 (49) -53 (-47) -13 (-7) -0.5 -0.6 2 0.4 0.0

140 (60) -53 (-47) -13 (-7) 0.1 -2.0 10 0.8 -0.1

150 (66) -53 (-47) -13 (-7) 0.4 -2.7 14 1.0 -0.1

Section 9.2.1, Table 3--The Change in Average Non-Distillation Properties versus

base from the Jet Fuel Properties Survey

Participants provided property predictions and yields at specification flash points of

100°F (38°C), 120 °F (49°C), 140 °F (60°C), 150°F(66°C) and freeze points of

-40°F(-40°C) and -53°F (-47°C). The averages of the results are shown in Section 9.2.1,

Table 4 and Section 9.2.1, Table 5. Note that the properties are a function of the

distillation cut, crude type and other factors which causes significant scatter in the data.
Report of Task Group 6/7 on Fuel Properties

46

Flash

Point

°F (°C)

Freeze

Point

°F (°C)

Yield

Loss

(%)

Initial

Boiling

Point

°F (°C)

10%

Boiling

Point

°F (°C)

50%

Boiling

Point

°F (°C)

90%

Boiling

Point

°F (°C)

Final

Boiling

Point

°F (°C)

100 (38) -40 (-40) 0 279 (137) 344 (173) 402 (206) 481 (249) 555 (291)

120 (49) -40 (-40) 25 317 (158) 368 (187) 414 (212) 478 (248) 541 (283)

140 (60) -40 (-40) 50 355 (179) 393 (201) 426 (219) 474 (246) 527 (275)

150 (66) -40 (-40) 62 373 (189) 404 (207) 432 (222) 472 (244) 520 (271)

100 (38) -47 (-53) 28 287 (142) 344 (173) 387 (197) 450 (232) 519 (271)

120 (49) -47 (-53) 53 344 (173) 368 (187) 399 (204) 446 (230) 504 (262)

140 (60) -47 (-53) 78 370 (188) 393 (201) 411 (211) 443 (228) 488 (253)

150 (66) -47 (-53) 90 391 (199) 404 (207) 417 (214) 441 (227) 540 (282)

Section 9.2.1, Table 4--Average Yields and Distillation Properties from the Jet Fuel

Properties Survey

Flash

Point

°F (°C)

Freeze

Point

°F (°C)

Viscosity at

–4°F (-20°C)

(centistoke)

Smoke

Point

(mm)

Density

(kg/m3)

Aromatics

Content

(%)

Heat of

Combustion

(mJ/kg)

100 (38) -40 (-40) 5.7 22.0 815 18.0 43.1

120 (49) -40 (-40) 6.3 20.6 823 18.4 43.1

140 (60) -40 (-40) 6.9 19.2 832 18.7 43.0

150 (66) -40 (-40) 7.2 18.6 836 18.9 43.0

100 (38) -53 (-47) 4.6 22.7 808 18.0 43.2

120 (49) -53 (-47) 5.2 21.4 817 18.4 43.1

140 (60) -53 (-47) 5.8 20.0 825 18.8 43.0

150 (66) -53 (-47) 6.1 19.3 829 19.0 43.0

Section 9.2.1, Table 5--Average Non-Distillation Properties from the Jet Fuel

Properties Survey

The loss in yield from any increase in the flash point specification is significant (>1%

yield per °F flash point) as shown in Section 9.2.1, Figure 1. The “yield loss” in Section

9.2.1, Table 4 and Section 9.2.1, Figure 1 is calculated versus the Jet A base case [100°F

(38°C) flash point, -40°F (-40°C) freeze point]. It represents the production lost when

distillation cut points are changed to keep the fuel within specification limits. At the

higher flash points and lower freeze point, many crude oils would produce no jet fuel at

all. [This leads to the apparent anomaly in Section 9.2.1, Table 4 where the final boiling

point for the 150°F (66°C) flash point Jet A-1 of 540°F (282°C) seems higher than

expected from the other final boiling points. This is caused by most of the crude oils

dropping out leaving only those with intrinsically good freeze point performance

remaining to average properties.]

Note that the higher growth rate of jet fuel production and use versus other fuels,

described in Section 12.2.4, is expected to apply pressure to future jet fuel availability.
Report of Task Group 6/7 on Fuel Properties

47

The loss in jet fuel yield associated with an increased flash point specification should

exacerbate this situation.

0

10

20

30

40

50

60

70

80

90

100

100 110 120 130 140 150

Flash Point (oF)

Yield

Loss

(%)

Jet A

Jet A1

Section 9.2.1, Figure 1--The Loss in Jet Fuel Yield (from the Distillation

of Crude Oil) as a Function of the Flash Point Specification

The 10% boiling points (temperature at which 10% of the material has distilled) and

initial boiling points vary linearly with the flash point specification temperature as shown

in Section 9.2.1, Figure 2.

0

20

40

60

80

100

120

140

160

100 110 120 130 140 150

Flash Point Specification (oF)

Change in 

Boiling Point 

(

o

F)

Jet A Initial

Boiling Point

Jet A1 Initial

Boiling Point

Jet A & Jet A1

10% Boiling Point

Section 9.2.1, Figure 2--The Linear Relationship between the Front End Distillation

Parameters and the Flash Point Specification Temperature Found in the Jet Fuel

Properties Survey

These distillation results (Section 9.2.1, Table 2) provide insight concerning why jet fuel

properties change when the flash point is raised. Material is excluded from the “front

end” (more volatile end) of jet fuel to meet the flash point specification resulting in

increased initial boiling and 10% boiling points. The front end of jet fuel helps to

dissolve straight chain paraffin molecules that can crystallize at low temperatures to form

wax. The loss of the front end material requires the back end to be reduced (resulting in
Report of Task Group 6/7 on Fuel Properties

48

lower 90% and final boiling points) to remove large straight-chain paraffin molecules to

maintain freeze point performance.

The difference in Jet A [-40°F (-40°C) freeze point] and Jet A-1 [-53°F (-47°C) freeze

point] is mostly the reduced back end fraction in Jet A-1 (lower 90% and final boiling

points). This acts to reject more of the large straight-chain paraffin molecules that can

form wax.

The jet fuel property most impacted by a change in flash point specification appears to be

viscosity. Viscosity increases are linear with flash point (Section 9.2.1, Figure 3). The

results demonstrate the role that the back end material plays in jet fuel viscosity: the

viscosities for Jet A-1 fuels [−53°F (-47°C) freeze point] were significantly lower than

those for Jet A were [−40°F (−40°C) freeze point].

The results indicate that a flash point specification of 120°F (49°C) could result in an

increase to 5.77 centistoke for the jet fuel pool viscosity at -4°F (-20°C). This is based on

an estimate of 5.17 centistoke for the current jet fuel pool viscosity at -4°F (-20°C).

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

100 110 120 130 140 150

Flash Point Specification (oF)

Change vs. 

Base

Jet A Viscosity (cSt)

Jet A1 Viscosity (cSt)

Jet A Heat of Combustion

(mJ/kg)

Jet A1 Heat of Combustion

(mJ/kg))

Section 9.2.1, Figure 3--The Changes in Jet Fuel Viscosity [at -4°F (-20°C)] and Heat

of Combustion versus Flash Point found in the Jet Fuel Properties Survey

The combustion properties (aromatics content and smoke point) showed degradation in

high flash point fuels (Section 9.2.1, Figure 4). The results were linear with smaller flash

point changes showing smaller property changes.

These results indicate that a flash point specification of 120°F (49°C) could result in an

increase of the average jet fuel aromatics content to 19.0% and a reduction in the average

smoke point to 20.3mm. This is based on current jet fuel pool estimates of 18.6% for

aromatics content and 21.7mm for smoke point.
Report of Task Group 6/7 on Fuel Properties

49

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

100 110 120 130 140 150

Flash Point Specification (oF)

Change vs.

 Base

Jet A Aromatics Content (%)

Jet A1 Aromatics Content (%)

Jet A Smoke Point (mm)

Jet A1 Smoke Point (mm)

Section 9.2.1, Figure 4--The Changes in Jet Fuel Aromatics Content and Smoke

Point versus Flash Point Specification found in the Jet Fuel Properties Survey

The density shows a small, linear increase as the flash point specification increases

(Section 9.2.1, Figure 5). Based on an estimateError! Bookmark not defined. of the current jet

fuel pool density of 814 kg/m3, a flash point specification of 120°F (49°C) would

increase the average jet fuel density to about 822 kg/m3.

-10

-5

0

5

10

15

20

25

100 110 120 130 140 150

Flash Point Specification (oF)

Change vs. Base Jet A Density (kg/m3)

Jet A1 Density (kg/m3)

Section 9.2.1, Figure 5--The Changes in Jet Fuel Density versus Flash Point

Specification found in the Jet Fuel Properties Survey.

The heat of combustion was slightly negatively impacted by increased fuel flash point

specifications (Section 9.2.1 Figure 3).
Report of Task Group 6/7 on Fuel Properties

50

On average, jet fuel sulfur content was essentially unaffected by the changes in

distillation.

9.2.1.3 The Impact of Modified Jet Fuel Refining

An increased flash point specification could cause more jet fuel to be produced to the

smoke point, aromatics content, or JFTOT specification limits but the magnitude of this

change cannot be estimated with current knowledge. The scenario is that an increased

flash point specification could cause reduced jet fuel availability. Reduced availability

could invite refiners to maximize jet fuel yield by blending refinery streams, not normally

used for jet fuel, as jet fuel. For example, kerosenes from catalytic crackers and coker

units have high aromatics contents, low smoke points, and poor thermal oxidative

stabilities. If hydrotreated to improve stability, these can be blended as jet fuel but

generally are not because the increased yields are small compared to the effort required to

maintain compliance with the limiting smoke point, aromatics, and JFTOT specifications.

A shortage of jet fuel could result in incentives for using these streams in jet fuel with the

result that the jet fuel pool would shift towards the specification limits with regard to

these properties.

Another possibility that cannot be quantified on the short time scale of this study is that

an increased flash point specification is likely to cause more jet fuel to be produced by

severe hydroprocessing. In general, severe hydroprocessing improves jet fuel thermal

stability. However the pressure to maximize productivity may lead to increased catalyst

run life with resultant degradation in thermal stability in localized situations. Another

issue with severe hydroprocessing is that the produced jet fuel can have poor lubricity

properties. Lubricity is usually restored by blending with good lubricity fuel or corrosion

inhibitor/lubricity additives.

9.2.1.4 Local Impacts

The average overall shifts in jet fuel properties resulting from an increased flash point

specification, described above, may be magnified in some locations. A specific example

is that the increased flash point specification may cause a high proportion of jet fuel in

some local areas to be produced to the viscosity limit. The issue, here, is that some

naphthenic crude oils produce jet fuels that have low freezing points and relatively high

viscosities. If the initial boiling points of these jet fuels are raised to increase flash

points, the viscosities will increase because the light material is removed but not much of

the heaviest material. (Little change is needed in the distillation final boiling points to

meet the freeze point specification.) Depending upon the extent of a flash point

specification change, refineries processing primarily these naphthenic crude oils (for

example some California refineries) may find the viscosity specification to be yield

constraining. The result is that some jet fuel batches may have viscosities at -4°F (-20°C)

very close to 8 centistoke instead of the 5.2-6.7 centistoke range predicted from the

results shown above.
Report of Task Group 6/7 on Fuel Properties

51

Another example of a possible local impact results if the increased use of severe

hydroprocessing to produce jet fuel leads to a locality having predominately low lubricity

jet fuel.

9.2.1.5 The Impact of Uncertainty in Fuel Properties

The uncertainty concerning the performance-related properties of a high flash point jet

fuel should be viewed as a risk.5 The impacts cannot be quantified at this time, but

greater flash point specification changes increase the significance of the concerns raised

above.6 This uncertainty brings the risk that properties may shift sufficiently to impact

equipment operation.

9.2.2 Fuel Property Effects on Airframes

9.2.2.1 Material Compatibility

Aircraft materials are evaluated for compatibility with jet fuels. Metals, coatings, seals

and sealants are tested with a representative fuel and with a fuel that contains 30%

toluene and 0.4% sulfur. Any high flash point fuel would not exceed the extremes in

properties already checked since the fuel must meet the 25% aromatics and 0.3% sulfur

limits in the fuel specification. No material compatibility problems in the airframe are

anticipated from using high flash point fuels.

9.2.2.2 Heat Content and Density

The heat content and density of jet fuel are controlled by the fuel specification. Any

higher flash point fuel would meet the current fuel specification requirements. However,

on the average, a 140oF(60oC) flash point fuel will have a higher fuel density per gallon

but a lower energy per unit weight when compared to delivered Jet A/A-1. There could

be a slight benefit for those aircraft that are limited by fuel tank volume and a slight

penalty for those aircraft that are limited by gross weight at takeoff. The anticipated

aircraft performance change for burning a high flash point fuel (HHF) is shown in Table

1. The performance change is based on a Jet fuel with a density of 6.7 pounds per gallon

and a lower heating value of 18,580 Btu per pound as compared with a high flash jet fuel

with a density of 6.8 pounds per gallon and a lower heating value of 18,525 Btu per

pound.

 

5

 For more discussion see Section 11.4.

6

 Sections 9.2.1.3 and 9.2.1.4.
Report of Task Group 6/7 on Fuel Properties

52

737-300 

737-700

747-400

757-200

767-300

40

60

85

50

60

777-200

-6

-7

15*

-9

60**

-23 100

-52

-48

-753

-114

-347

-539

0.3%

0.3%

0.4%

0.3%

0.4%

0.4%

(nmi)

Constant TOGW,

Payload

Constant Payload,

Fuel Volume

Constant

TOGW, Range

Constant

Payload, Range

HFF - Jet A HFF - Jet A HFF - Jet A HFF - Jet A

Jet A

Δ Design Range

(nmi)

Δ Range at Fuel

Volume Limit

Δ Block Fuel

(%)

Δ Payload

(lbs)

* Fuel volume limited with Jet A

** Fuel volume limited with both Jet A and High Flash Fuel (HFF)

TOGW - Takeoff gross weight

Airplane

Section 9.2.2.2, Table 1--Delta Change in Airplane Performance

with High Flash Point Fuel.

The changes identified in Table 1 would result if the flash point was increased by

20oF(11oC). [See section on fuel property effects predictions for property changes versus

flash point increase.] For the U. S., 120oF(49oC) minimum flash point fuel will not differ

significantly in heat content and density from the currently delivered Jet A fuel and no

impact to range or payload is expected.

9.2.2.3 Freezing Point

The requirement for freezing point of jet fuel is independent of flash point. The

requirement is to deliver to the engine fuel with a temperature 5.4oF(3oC) above its

freezing point. For Jet A, the pilot must initiate action to keep the fuel from getting any

colder if the fuel temperature reaches -35oF(-37oC). A high flash point fuel is not

expected to behave differently from other kerosene fuels. Currently the freezing point of

delivered Jet A in the U. S. averages well above the specification minimum of -40oF

(-40oC). Although airlines do not take advantage of the better than specification

minimum fuel, aircraft have operated with additional margin as a result of the product

quality give away.

The freezing point of Jet A is becoming an issue for the new routes opening up over the

Northern latitudes. The fuel temperature in wing tanks can get as low as -44oC(-47oF)

during long range flights on polar and Siberian routes in the winter. A Jet A type of fuel
Report of Task Group 6/7 on Fuel Properties

53

may not be satisfactory for commercial aviation operations on these routes in the winter.

Some aircraft dispatched from the U. S. may require a lower freezing point fuel. The

need for a low freezing point fuel is currently being assessed by the airlines.

Implementing a high flash point fuel is likely to end the freezing point quality give away

currently being provided to the airlines and end all efforts to identify the actual fuel

freezing point at the time of refueling.

9.2.2.4 Viscosity

Viscosity at low temperatures is an engine and APU concern and not an issue in the

airframe fuel system (see Section 9.2.3).

9.2.3 Fuel Property Effects on Engines and Auxiliary Power Units

9.2.3.1 General

This section describes how the predicted changes in fuel properties, as flash point

requirement is increased, could affect gas turbine engine operability and performance.

This information is presented as a consensus view based analysis of fuel property

information provided by API in its survey and model reported in 9.2.1 and inputs from

engine and APU manufacturers within Task Groups 6 and 7. The engine manufacturers

considered a wide range of engine types, thrust ratings and aircraft applications

(turboprop, turbojet and turbofan designs have been included in the deliberations).

Engine and APU aerothermal and fuel delivery system performance, integrity and

durability are affected in many complex ways by the properties of fuel being used.

Section 9.2.3, Table 1 which is included as Appendix 4, summarizes the potential impact

changes in fuel properties can have on engine and APU operation. The proposed increase

in flash point would, if achieved without change to other fuel properties, have minor

effects on engine/APU operability but would not improve the overall safety of these

units. However, the API model calculations clearly indicate that in order to achieve

production that meets the current demand for jet fuel there would be a significant shift in

several important fuel properties. It is therefore important to consider the impact of all

these property changes when assessing the overall risks and benefit of increasing fuel

flash point.

Since most civil engines and APUs are approved to run on both JetA/A-1 and military

high flash point JP-5 it would appear that if the proposed fuel fell within these bounds

there would be no problems or risks associated with its use. This is, however, a gross

over-simplification.

As the flash point requirement rises, predicted fuel properties and combinations thereof

increasingly depart from current experience of either Jet A/A-1 or JP-5 both in-service or

used in validation testing. Further, API input clearly indicates the use of alternative raw

materials and processes to recover yields to current levels may result in hitherto unknown
Report of Task Group 6/7 on Fuel Properties

54

changes in fuel properties by, for instance, the introduction of new molecule

types/species.

The following paragraphs highlight the most important implications of operating on the

fuel types predicted by the API model calculations described in Section 9.2.1.2. The

predicted effects on engine and APU operation are our best judgment at this time given

there is no operating experience for a civil flash point modified fuel and only very limited

documented experience of extended civil operation with military JP-5 fuels. It is also

important to note that the model only provides predicted mean values; no population data

is available to indicate value distribution around the mean or variations between

geographic locations. The full range of possible scenarios cannot therefore be addressed.

Testing to evaluate the effects and provide quantitative data would be required to assess

the impact on the engine/APU in many instances. Such testing would have to be carried

out on referee fuels manufactured specifically to represent examples of the fuels likely to

be encountered in service. The type of testing which may be required is described under

the fuel property headings below and may include laboratory, rig or full engine testing.

(In service monitoring may also be required to determine long term effects). An

internationally coordinated and funded program would be an appropriate way forward.

9.2.3.2 Flash Point and Distillation

Progressive increases in flash point and the associated change in distillation will by

definition reduce fuel volatility. This makes combustion initiation more difficult under

adverse conditions such as altitude relighting and cold starting. The potential impact

becomes increasingly severe as the flash point increases. Task Group 6/7 is concerned

that high flash point fuels could adversely impact both ignition performance and/or

engine start times at the extremes of the relight envelope and on the ground during cold

temperature starting.

The requirement to fully evaluate the actual impact on ignition and relight performance

would be a serious consideration for the higher reference flash point fuels.

Mitigating actions include re-scheduling of fuel control systems, or revision of the engine

relight envelopes.

9.2.3.3 Viscosity

Main engines and APUs are designed to start and operate using a variety of kerosene and

wide-cut fuels, up to a maximum fuel viscosity of 12 centistokes (cSt). At extreme cold

start conditions the viscosity becomes the prime limiting factor. With the current pool of

jet fuels, engine cold starting has not presented a significant problem in the continental

United States (U.S.) or Europe. However, engine cold starting is an operational concern

in extreme cold conditions (see Section 11.2).
Report of Task Group 6/7 on Fuel Properties

55

Section 9.2.3.3, Figure 1 shows fuel viscosity as a function of temperature for Jet A and

JP-5 fuels. As shown, the current ASTM D1655 specification maximum Jet A fuel (8 cSt

max. at –20°C) can reach the 12 cSt viscosity limit at approximately –20°F, However, the

viscosity range for current jet fuels is well away from the specification limit. For

reference, the U.S. mean jet fuel viscosity is approximately 5 cSt at –20°C (Section

9.2.3.3, Reference 1) and the United Kingdom (UK) mean viscosity is approximately 3.8

cSt at –20°C (Section 9.2.3.3, Reference 2). Note that Europe and the UK use Jet A-1

fuel, which has a lower freeze point than Jet A fuel (usually accompanied by lower fuel

viscosity).

0.80

1.00

1.25

1.50

2.0

3.0

4.0

6.0

10.0

15.0

30.0

50.0

-60 -30 0 30 60 90 120 150 180 210

-60 -30 0 30 60 90 120 150 180 210

MIL-T-5624 JP-5

Specification Limit

ASTM D1655 Jet A

Specification Limit

Avg Jet A (1)

Avg JP-5 (1)

12 cst Limit

(1) NIPER-199 PPS 97/2

Range for 39 Jet A samples(1)

Fuel Temperature, F

Viscosity, Centistokes

Section 9.2.3.3, Figure 1--Fuel Viscosity as a Function of Temperature

The API survey has indicated that an increase in the commercial jet fuel flash point

would result in an increase in fuel viscosity. A high flash point fuel will therefore reach

the 12 cSt maximum viscosity limit at a higher temperature than current commercial jet

fuels. Section 9.2.3.3, Figure 2 shows the API predicted fuel viscosity at –20°C as a

function of the fuel flash point. As seen in Figure 2, any increase in flash point will

increase the average viscosity above current levels for Jet A (-40°C freeze point) fuel,

and for any increase above approximately 130°F for Jet A-1 (-47°C freeze point) fuels.
Report of Task Group 6/7 on Fuel Properties

56

0

2

4

6

8

10

100 110 120 130 140 150

Flash Point, F

Viscosity @ -20C, cst

-40C Freeze Point

-47C Freeze Point

12 cst @ -40F

Section 9.2.3.3, Figure 2--Predicted Fuel Viscosity as a Function of Fuel Flash Point

As the fuel viscosity exceeds the 12 cSt point, there will be an increasingly deleterious

effect on fuel atomization. The combination of increased viscosity and reduced fuel

volatility with the high flash point fuels could result in slow and difficult engine starting,

or a no-start. An increase in engine ground start problems in cold weather would be a

major operability concern. Engines that currently have a reduced operating envelope

(higher minimum operating temperatures) when using high flash point JP-5 fuel, may

need to also restrict cold weather operation with a commercial high flash point fuel.

An additional concern would be APU starting during or after a long flight, or after

extensive time on the ground in extreme cold conditions. APU ground start problems

could result in an increase in flight delays while backup ground start carts are brought up.

Cancellations of some flights (ETOPS) may occur if there is significant risk of the APU

failing to start after long flights. See Section 9.2.3.10 for additional information on the

effect of fuel property changes on APU operation and mitigating actions.

The risk of engine and APU cold starting problems could be mitigated by revising the

viscosity limit to a maximum of 12 cSt at -40°C. Based on a viscosity correlation

provided by the petroleum industry, a fuel viscosity of 5.3 cSt at -20°C corresponds to a

viscosity of 12 cSt at -40°C (-40°F). Further study on reference fuels would be required

to finalize this value.
Report of Task Group 6/7 on Fuel Properties

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Comparison of the U.S. data (Jet A -freeze point -40°C) and European data (Jet A-1 -

freeze point -47°C) also shows that to some extent the higher viscosity levels are avoided

when a -47°C freeze point is specified. The downside of changing U.S. production to -

47°C would introduce further yield limitations over and above the levels already

predicted by the API/EUROPIA survey (see Section 12.2, Appendix 14.1 and 14.2).

Increased viscosity would also slightly reduce the heat transfer efficiency of fuel/oil heat

exchangers, and cause increased oil temperatures. Fuel injector cooling by the fuel will

also be reduced slightly by the same effect. These effects need to be modeled or tested

using the target properties of the proposed high flash point fuels to determine the ultimate

impact (if any) on component or system operation and durability.

9.2.3.4 Aromatics and Smoke Point

The relatively small increase in aromatics levels from 18.0 (for 100°F flash) to 19.0%

(for 150°F flash) are not of concern per se. The decrease in smoke point which is closely

related to aromatic content and type does however change significantly, falling from 22-

23 mm for 100°F flash point fuel to 19 mm for 150°F flash (current minimum is 18 mm).

Based on established relationships between aromatics level and smoke point, this data

implies that either the aromatic types would be changing with potentially increased multiring species, or, there is inaccuracy in the smoke point prediction. Assuming the model is

correct the changes have two potential impacts:

1. Aromatics content and type influence swell of certain elastomer types. Significant

change from current swell levels could cause seal problems leading to potential

additional corrective maintenance actions.

2. Lower smoke point fuels have lower combustion quality. Such fuels increase the

potential for smoke and flame radiation reducing overall hot-end durability. The

magnitude of these effects and impact on operating costs are likely to be engine type

specific.

Laboratory testing on reference fuels to evaluate elastomer compatibility and impact on

emissions and hot-end durability may be appropriate when the revised specification is

finalized. Increasing the minimum smoke point specification requirement is an option

that should be given serious consideration to offset combustion-related problems.

Given the predicted downward shift in combustion properties the current requirements

for certification emissions testing reference (see Section 9.2.5.1) may need to be

redefined for future engine certifications.

9.2.3.5 Total Sulfur Content

The API model did not predict any impact on the sulfur level of the final product. Any

increase in sulfur level from the initial distillation would be offset by the use of
Report of Task Group 6/7 on Fuel Properties

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hydroprocessing. No significant effect of fuel sulfur content on engine operation is

expected.

9.2.3.6 Thermal Stability

No quantitative data is available on the impact of the proposed changes in flash point on

thermal stability. The API survey identifies that there will be an increasing incentive to

use less desirable streams and processes to offset the reduction in yield. This has the

potential to reduce both storage and thermal stability of the fuel pool. Conversely, there

are indications that increased use of hydrogen-based processing will be used, which could

improve thermal stability.

A significant reduction in the stability of the fuel pool would increase deposition and

consequent fouling of fuel control units and injectors, increasing operating costs due to

the increased maintenance. The magnitude of this effect cannot be estimated with the

current data, which is only qualitative. Laboratory and rig scale testing would provide a

quantitative prediction on the long-term impact of using these fuels.

At this stage removal of the two tier thermal stability limit present in the ASTM D1655

specification and introduce a single requirement of 260°C, or higher, could mitigate

thermal stability related problems.

9.2.3.7 Freeze Point (Cold Flow Properties)

Freeze point (the point at which wax-like crystal disappears when warming the fuel) is

one of the primary yield limiting parameters. To maximize jet fuel yield, high flash point

fuels may be much nearer to the freeze point than at present (less margin). Also, the

increased use of hydrocracked product will lead to a much sharper transition between

liquid and almost solid phases. Pour points of the fuel (the temperature at which the fuel

will not flow) are likely to be much closer to the freeze point and potentially there will be

changes in crystal size distribution compared to existing fuels.

Engine fuel systems are designed on the assumption that fuel is free from wax and water

crystals at the entry to the low pressure (LP) fuel filter, so filter element blockage will not

occur under normal circumstances. Most engines use a fuel/oil heat exchanger to heat the

fuel prior to entering the LP filter, which will prevent filter blockage during operation

(not during cold starting on the ground however). For engines without an upstream fuel

heater or a filter bypass, LP filter blockage is considered a hazard to engine safety.

However, low pressure filter blockage by wax crystals would normally only cause bypass

flow warnings and require subsequent maintenance action.

Given the potential changes in cold flow properties of the high flash point fuels,

evaluation is required to ensure heat input to fuel is sufficient to ensure that very cold fuel

will un-freeze prior to the low-pressure fuel filter.
Report of Task Group 6/7 on Fuel Properties

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9.2.3.8 Lubricity (Lubricating Quality)

Pressure on the producers to maintain yield will almost inevitably result in increase the

use of hydrocrackers, hydroprocessors and the possible blending of synthesized product.

These types of processes reduce fuel lubricity significantly. Low lubricity fuels can cause

increased wear rates in pump and control system components. This is primarily a

component life limiting issue and hence operating cost would increase if lubricity

reduced significantly. However, recent isolated incidents have demonstrated that with a

continuous diet of poor lubricity fuel sudden component failure can occur.

Lubricity is not currently a specification test requirement. Inclusion of a lubricity

requirement in the specification would significantly reduce the risks described. However,

further debate is required to define the limit to be imposed and how it would be applied.

An alternative option is to increase the use of lubricity improving additives. If it became

necessary to use these additives on a regular basis this would incur cost and logistics

penalties.

9.2.3.9 Heat of Combustion and Density

Predicted changes in both heat of combustion and density are not expected to adversely

impact engine performance. Lower heat of combustion will increase fuel consumption

(on a weight basis). A significant shift in the population of density or heat of combustion

or the established relationship between these two parameters may necessitate recalibration of fuel control units and flowmeters. Note that flowmeters may also be

sensitive to viscosity changes.

9.2.3.10 APU Operational Impact

The Auxiliary Power Unit (APU) is a small gas turbine engine used on all major transport

aircraft and on most regional and executive aircraft. The APU is typically used as a

power source for the aircraft air-conditioning units and electrical systems during ground

taxi and gate operations, and as a power source for main engine starting during rollback

from the gate. The APU is only used in-flight as an alternate electrical source in the

event of a failure of a main engine generator.

Under normal conditions the APU is considered non-essential equipment. Non-essential

equipment may be non-operational without jeopardizing safe operation of the aircraft

either on the ground or in-flight. There are certain conditions however, when the APU is

considered essential equipment on the aircraft minimum equipment list. Essential

equipment is necessary for maintaining safe operation of the aircraft either on the ground

or in-flight. For example, the APU may be considered essential equipment for ETOPS

(Extended Twin Operations) flights, where a twin-engine aircraft is more than a specified

flight time away from an airport (such as on most overseas flights). To obtain and

maintain an ETOPS rating, an APU must demonstrate reliable altitude and cold starting

capability, usually up to the maximum aircraft cruise altitude (some ETOPS APUs must

be operating prior to entering the ETOPS flight leg). This is significantly different than
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main engine relight requirements, which are typically only up to 20 to 25 thousand feet

altitude.

Since the APU compartment is usually not heated, the APU and the fuel are cold soaked

at the prevailing total air temperature conditions in-flight. Some regional and executive

aircraft do not have an APU inlet door, resulting in increased airflow through the engine

during flight with a corresponding decrease in time to stabilize at the cold soak

temperature. Even with a closed APU inlet door, the APU and fuel are usually stabilized

at the cold soak conditions after three to four hours in-flight. Typical APU cold soak

temperatures for a long range flight would be in the -20°F to -40°F range, but they can be

significantly lower for extreme cold or arctic conditions. The combination of the high

altitude and extreme cold soak requirements make APU starting a major design

consideration. APU usage varies considerably depending on the operator, the aircraft

type, and any local airport restrictions, but the APU is frequently started after landing and

prior to arriving at the gate.

APUs are designed to start and operate using a variety of kerosene and wide-cut fuels, up

to a maximum fuel viscosity of 12 centistoke. The refinery survey has indicated that an

increase in the flash point of commercial jet fuel would result in an increase in fuel

viscosity. The combination of reduced fuel volatility and increased viscosity with the

high flash point fuels could result in slow and difficult APU starting, or a no-start. Of

particular concern would be APU starting during or after a long flight, or after extensive

time on the ground in extreme cold conditions. APU ground start problems could result

in an increase in flight delays while backup ground start carts are brought up, or

cancellations of some flights (ETOPS).

If the fuel flash point is increased over current levels, addition of a fuel heater at the APU

inlet may be required to maintain the fuel temperature above that corresponding to a

maximum viscosity of 12 centistoke, to ensure reliable starting for all ambient conditions.

Detailed measurement of fuel temperatures at the APU fuel control inlet for various

aircraft would be required to fully evaluate the impact of a fuel flash point change on

APU starting. The fuel heater could be run off the APU battery in-flight, using the

existing battery charger powered by the main engine generators. The fuel heater could

only be used on the ground when the electric power was provided by the gate in order to

prevent the APU battery from being discharged too low for subsequent starts. Retrofit

requirements for an APU fuel heater are provided in Section 8.2, with cost information

provided in Section 12.6.2.

9.2.4 Ground Infrastructure & Fungibility

Raising the minimum flash point of jet fuel would not impose significant constraints on

the U.S. fungible pipeline system. However, this is based on the assumption that this

constitutes a change in the current fuel specification as opposed to adding an additional

grade of jet fuel. (See Section 6.3 for additional information on pipeline transportation).
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There are significant differences in the operation of multiproduct pipelines between

Europe and the U.S. Traditionally, Europe has adopted a process of recertification after

any movement of jet fuel where contamination with the products can occur. In this

process, contamination sensitive properties such as distillation, flash point, freeze point,

existent gum are measured after the operation and results compared with the original

values. If any of the values have changed by more than permitted amounts (based on

reproducibility of the test method), contamination is suspected and an investigation is

conducted.

In the corresponding U.S. process, the fuel is simply tested against the specification.

Provided that the values still meet the specification, all is well. Traditionally, pipeline

companies set specifications for entry into their systems which exceed the product

specification by a considerable margin to give them a buffer to absorb the effect of cross

grade contamination.

Entry specifications for flash point in the U.S. are significantly higher than the flash point

minimum, probably reflecting the potential for contamination with gasoline. In Europe,

jet fuel is usually buffered between gas oil or diesel tenders (no likelihood of a flash point

decrease even if contamination occurs). In the U.S., the lower demand for gas oil/diesel

increases the likelihood that jet fuel will be buffered by gasoline tenders thereby

increasing the risk of flash point reduction from interface mingling. The net effect of this

is that jet fuel is normally produced much closer to the minimum flash point specification

than in North America.

9.2.5 Environmental Effects

9.2.5.1 Aircraft Emissions

Since the 1980’s, gas turbine engine emissions have been regulated by the U.S.

Environmental Protection Agency (EPA) as defined by 40CFR Part 87, Control of Air

Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures.

Within this regulation visible emissions (smoke) are regulated on all turbo-prop engines

with a shaft horsepower of 1000 kW (1340 HP) or greater, and all gas turbine engines,

Class T3, T8, and TF, of a rated output of 26.7 kN (6000 # Fn) thrust or greater. The

invisible emissions (unburned hydrocarbons, carbon monoxide and oxides of nitrogen)

are regulated for all gas turbine engines, Class T3, T8, and TF, of a rated output of 26.7

kN (6000 # Fn) thrust or greater. The current regulatory levels are:

Unburned Hydrocarbons - 19.6 grams/ kilonewton

Carbon Monoxide - 118.0 grams/kilonewton

Oxides of Nitrogen - (40 + 2 (Rated Pressure Ratio))g/kN

Smoke For T3, T8 & TF Class - 83.6 (Rated Output, kN)^ -0.274 SN

The engine manufacturer’s approach to meeting emission regulations has been by careful

design of both the fuel injectors, and the combustors into which these fuel injectors fit.

Because of this, most modern gas turbine engines have emissions levels which are well
Report of Task Group 6/7 on Fuel Properties

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below the regulatory values noted above, and the slight influence of fuel properties has

not been considered that important. It is considered unlikely that the changes in fuel’s

properties will drive any engine over the regulatory limits. If some particular engine

model is required to recertify, there will be some cost to the manufacturer, in as much as

three engine tests are required plus the cost of the report.

If and when a higher flash point commercial fuel is selected, the engine manufacturers

will have to emissions test their engines to determine how emissions levels have changed.

This is necessary because stationary facilities, such as airports, are required to do an

emissions inventory (including aircraft emissions) and report the results of these surveys

to the EPA. Any increase in emissions must be reported.

Based on the fuel properties extrapolations done by API, and for a significant (+40

degrees F) increase in fuel flash point, increases in fuel viscosity, density and surface

tension will generally result in slightly larger fuel droplets from the fuel injectors at the

engine idle operating condition. This in turn reduces the initial vaporizing rate of the fuel,

which can result in local fuel rich pockets in the combustor primary burning zone. These

rich pockets, when burned, produce fractionally higher levels of unburned hydrocarbons

and carbon monoxide. Further, if the increase in fuel flash point does result in higher

aromatics for the pool of fuels available, then it is possible that smoke emissions will

increase slightly for some engine models. But for many engine models this increase will

be so small as to lie within the ability to measure smoke level.

Relative to fuel properties, there is insufficient information to analytically quantify how

emissions would change. Studies of fuels effects done by the Air Force in the late 1970’s

and early 1980’s, were done on combustor and fuel nozzle designs that have been

superseded by the technology used in today’s engines. The only way to determine the

fuel property change effects on engine emissions would be to test today’s engines.

In summary, it is felt that increasing fuel flash point could cause some, very minor,

increases in gas turbine emissions levels, depending on how large a flash point change is

selected. Up to about a 15 degree increase in flash point it is unlikely that the change in

important fuel properties would be sufficient to cause measurable change. As the selected

value of flash point increases away from the current fuels, it becomes more likely that

engine manufacturers will have to run emissions tests on their engines to (1) quantify the

increases in emissions levels for airport operator’s reports to the EPA and (2) assure that

engine models did not exceed EPA regulatory values for those engines which might now

be marginal in a particular contaminant.

9.2.5.2 Jet Fuel Manufacturing Emissions

CONCAWE, the European oil industry organization for environmental, health, and

safety, examined the effects of changing the jet fuel flash-point specification in the range

of 100°F to 140°F. The study involved an assessment of the effects on distillation yields

and an assessment of an EU refining simulation evaluating the overall impact and

remedial actions to restore the specified future demand quantity.
Report of Task Group 6/7 on Fuel Properties

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CONCAWE determined that restoring the jet demand would involve substantial

European investments in hydrocracking of approximately 25 million tons per year (Mtpa)

additional capacity with associated investments in hydrogen generation facilities. The

additional energy use in hydrocracking as well as the extra hydrogen consumption leads

to an increase in CO2 emissions estimated at 7-8 Mtpa.

The Task Group recommends that a linear interpolation of this data be used, which leads

to an estimated increase in CO2 emissions of 1.75-2 Mtpa per 10°F increase in jet flashpoint for the EU-15 countries. The increase in CO2 due to a 10°F increase in jet fuel

flash point would add about 1% to the total CO2 emissions from EU-15 refineries.

However, as a result of the Kyoto conference, there is a worldwide pressure to reduce

overall CO2 emissions.

9.2.5.3 Evaporative Emissions

Evaporation of fuel from tanks at airports, terminals, and refinery storage tanks depends

on the vapor pressure of fuel at ambient temperatures. Because jet fuel is a mixture, the

amount of fuel that can evaporate varies as a function of ullage to fuel volume, the

amount of weathering of the fuel, and other factors. One way to obtain an estimate of the

amount of evaporative emissions that can occur is to examine changes in the true vapor

pressure with flash point. The true vapor pressure is the pressure exerted by vapors of a

fuel in equilibrium at a specific temperature when the ullage to liquid volume ratio tends

to zero. Using the data of Section 9.2.1 and ASTM D2889, the true vapor pressure at

25oC as a function of flash point for jet fuel with a freezing point of -40oC can be

determined as shown in Section 9.2.5.3, Figure 1. Fuel with a freezing point of -47oC

should have comparable values.

Section 9.2.5.3, Figure 1--True Vapor Pressure of High Flash Jet A Fuel
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Evaporative emissions should be reduced with increasing flash point as the ratio of the

true vapor pressure. Section 9.2.5.3, Table 1 shows the approximate reduction in

evaporative emissions anticipated.

Flash Point (oF) % Reduction in Evaporative

Emissions

100 0

110 24

120 53

130 60

140 73

150 91

Section 9.2.5.3, Table 1--Reduction in Evaporative Emissions

with Increasing Flash Point

Since its initial boiling point and T10 distillation point largely drive a fuel’s vapor

pressure, raising the minimum flash point will lower the vapor pressure of jet fuel, further

diminishing its already low evaporative emissions.

9.2.6 Additives in High Flash Jet Fuels

Additives are used in jet fuel to affect its properties. In general, additives are effective

when used to control minor constituents in the fuel, or when they are used to affect some

property, which is sensitive to minor constituents. Additive concentrations, with one

exception, are in the parts-per-million range. Bulk properties are not normally affected.

Hence, it is not anticipated that an additive could be found which could affect flash point,

freezing point, distillation, or other compositional properties.

A variety of optional and mandatory additives are used in jet fuels. The probable changes

in performance, and any increased need for these additives are discussed in the following

paragraphs.

9.2.6.1 Antioxidants

These additives are used to prevent the formation of peroxides during storage of fuels that

have been hydrogen-treated. Use of 17-24 parts per million (ppm) is mandatory in

hydrogen –treated fuels outside the U.S. and in U.S. Military jet fuels. Use is optional in

jet fuels meeting ASTM D 1655. The performance of these additives is unlikely to show

any dependence on the flash point of the fuel; they have been used effectively in JP-5

high flash fuel for many years.

While the need for antioxidants is not affected by flash point, a somewhat larger fraction

of jet fuel outside the U.S. might require them if hydrocracking or other hydrogentreating processes are used to maximize the availability of jet fuels.
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9.2.6.2 Metal Deactivator Additive

Metal deactivator additive (MDA) is used in jet fuel to counter-act the tendency for

dissolved trace metals to reduce stability of jet fuel during storage and during high

temperature exposure in the turbine engine. A small proportion of jet fuel is treated with

MDA, mainly when minute traces of copper could be dissolved in fuel during refining or

during transportation. Use of 2 – 5.7 ppm of this additive is optional. No change in

performance or the frequency of use for this additive is expected based on flash point

considerations.

9.2.6.3 Static Dissipator Additive

Static dissipator additive (SDA) use is optional in U.S. civil jet fuels meeting ASTM D

1655, but is mandatory in some military jet fuel requirements and in most other civil jet

fuel specifications. This additive increases the fuel conductivity and hence aids in

dissipating electrostatic charge that has been generated by the fuel passing through filters

used during fuel transportation and at airports. Minimizing the static charge is necessary

to prevent the possibility of a spark that could ignite fuel vapors or mists. Increasing the

flash point may not change the need for this additive, especially if lower flash point jet

fuels (TS-1 and Jet B) may still be present in aircraft tanks.

An increase in the minimum flash point of jet fuel would require an increased

concentration (normally 0.5 to 1.5 ppm) of SDA to give the necessary conductivity

increase, but will not otherwise affect performance. Studies (see 9.2.1) show that jet

fuels with higher flash point will have a higher average viscosity, and the performance of

SDA will be slightly reduced since response is, in part, determined by this property.

9.2.6.4 Corrosion Inhibitor/Lubricity Additives

These additives are required at concentrations of 9-15 ppm in military jet fuels to

improve the lubricity of jet fuel in engine parts such as pumps and engine controls, and

can be used in civil jet fuels with the permission of the purchaser. Currently, a very small

portion of civil jet fuel contains lubricity improver additive. Lubricity of hydrogen

treated fuels is variable and may be poor; lubricity of non-hydrogen treated jet fuel is

normally adequate. A steady diet of poor lubricity fuel can cause component failure in

flight. It is known that only a few percent of fuel with good lubricity needs to be

commingled to give satisfactory performance. Military aircraft operating from fixed

bases may not benefit from commingling and wear problems have been eliminated by use

of lubricity additives.

Except in very rare circumstances, civil aircraft receive an adequately varied fuel diet to

ensure good performance, and these rare circumstances are being managed satisfactorily.

However, the current equilibrium might be disturbed by significant changes in fuel

production methods and distribution, and the potential for serious lubricity problems in a

rapidly changing situation should not be taken lightly. Lubricity properties are a current

concern in jet fuel specification activities.
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Corrosion inhibitor/lubricity additives may be added at any point during distribution.

Currently, broad use of this additive in civil fuels is inhibited by specification

requirements, which usually require acceptance by purchasers. These additives have a

negative effect on the performance of filter coalescers used to remove particulates and

water from jet fuels. Improved coalescers being developed for military use have

increased resistance to these and other additives, and might reduce the risks of using

lubricity improvers. At this time, however, broad use of lubricity improver is strongly

inhibited by water separation concerns.

9.2.6.5 Fuel System Icing Inhibitor (Anti-icing Additive)

This additive, diethyleneglycol monomethyl ether (DiEGME) is used in high

concentrations (0.10 to 0.15 volume percent) relative to other additives. It dissolves in

water, which may precipitate from the fuel and prevents freezing in cold climates or at

high altitude. Large commercial aircraft with filter heaters do not require this additive,

but many small aircraft need it. Because this additive has been used successfully in JP-5

for many years, there is no reason to expect any change in efficacy, or to expect any

change in the need for its use.

9.2.6.6 Miscellaneous Additives

• Biocides are used intermittently in some aircraft to inhibit microbiological growth.

There will be no change in the need for or the performance of these additives.

• Tracer A is a new additive being developed for intermittent use to detect leaks in

airport fuel hydrant systems. There will be no change in the need for or performance

of this additive.

• JP-8+100 Stabilizer is a new additive being developed for use in military aircraft, to

improve the thermal stability of jet fuel. While not yet approved for use in civil fuels,

this additive is likely to be used in the future. There is no likely change in

performance of this additive based on flash point alone, but these additives have

performed differently in different fuels. If unusual components are more commonly

used to meet flash point and availability, the need for the additive could increase or

new formulations may have to be developed. Improved filter coalescers, under

development for military use of this additive, would probably be required. Use

concentrations are 100 ppm or higher.

9.2.6.7 Research Opportunities for Additives

Freezing point is a property that is a strong function of the types of molecules present in

the fuel. It is highly unlikely that wax solubility could be affected by an additive.

However, pour point depressants could affect flow properties at low temperature. These

work by altering the size of the wax crystals formed. While this has worked well in diesel

fuels, there are occasionally times when agglomeration of the wax occurs, causing

operational problems. This would not be tolerated in aircraft. However, if the jet fuel
Report of Task Group 6/7 on Fuel Properties

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specifications were changed to a minimum pour point instead of freezing point, and better

additives were developed, increases in productivity would occur. It is unlikely that this

research effort and related no-harm testing could be completed in less than five years.
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10.0 AIRWORTHINESS REQUIREMENTS

Based on the API model predictions, a higher flash point fuel is likely to depart from the

current engine and API test and service experience in terms described previously. The

magnitude of changes is increasingly severe as flash point increases.

 Possible mitigating actions to off-set adverse impacts on engine and APU operation

(where available) were discussed in Section 9.2.3. These include:

• Hardware modifications, adjustments and re-calibrations

• Revisions to the fuel specification requirements in additions to the increase in flash

point

• Revised aircraft operational limits

The influence on airworthiness may be initially modest with respect to main powerplant

considerations for minor increases in flash point, to requiring significant corrective

actions for the highest flash point fuels. Moreover, there is the potential for the APU to

be significantly affected by relatively small increases in the flash point.

 Dependent on the magnitude of changes in fuel properties, specification limits, and

hardware changes, further actions may be required by the engine, APU, hardware (e.g.,

fuel system unit and component) manufacturers and airworthiness agencies to ensure that

civil airworthiness requirements continue to be met.
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11.0 SAFETY

11.1 Operation on Low/High Flash Fuels

Commercial airlines make frequent flights to other parts of the World and it is unknown

if some parts of the World will, or will be able to change to a high flash point fuel.

Therefore aircraft will continue to uplift low flash fuels particularly in Russia and the

Commonwealth of Independent States (C.I.S.). Defueling and the transfer of fuel

between tanks is not practical for commercial operations. In today's global market, there

is no practical way to avoid mixing fuels from different parts of the world.

European airlines with a high number of flights to Russia and the C.I.S will have the

greatest exposure, uplifting approximately 35% of the fuel required in these States.

Aircraft manufacturers will also need to continue to certify aircraft for safe use of these

fuels particularly when sold to an operator in these regions.

11.2 Operation in Cold Climates

11.2.1 Canada

From the Canadian point of view, an increase in flash point of kerosene-type aviation

fuels would be a move in the wrong direction. Increasing the flash point would reduce

the more volatile, low-boiling components of the fuel, which in turn leads to an increase

in viscosity and exacerbates an already tenuous cold starting situation. Cold starting

problems and "hung starts" are currently not uncommon during cold weather operations

at major Canadian airports such as Winnipeg and Edmonton, even though these airports

operate on Jet A-1 fuel. In the far north, commercial operations are mostly on Jet B / JP4 although some Jet A-1 is in use.

Additionally, the Air Element of the Canadian Forces, despite a total conversion to

kerosene-type fuels by all its allies, continues to use wide-cut JP-4 as its standard fuel for

all land-based operations in order to insure starts under all conditions at any time of the

year. A one-year trial of JP-8 at a Canadian Forces base located near Vancouver proved

unsuccessful due to starting problems, particularly with rotary aircraft. The base reverted

back to JP-4 following the trial period.

In the Canadian view raising the flash point of kerosene fuels will, in all likelihood,

create more problems than it will solve and is not viewed as an improvement to flight

safety.

11.2.2 Scandinavia and the Baltic States

Scandinavian and Baltic States operators are similarly concerned with the proposal to

raise the flash point of the fuel and the resulting effect on the fuel viscosity and

subsequent cold starting problems which would severely disrupt their operation in winter

months.
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11.2.3 Russia and the C.I.S.

Russia and the C.I.S use a kerosene fuel whose properties are controlled by the Russian

specification GOST 10227 Grade RT and TS-1. The distillation range, viscosity and

freeze point limits of Russian fuels is designed to allow operation, cold starting and

engine re-light at very cold temperatures experienced in Siberia. These fuels are more

volatile than Jet A/A-1 with a minimum flash point of 28oC ( 82.4oF).

The Chinese also specify two grades of fuel, RP1/2 with similar characteristics and flash

points to the Russian fuels but state that they now only deliver Jet Fuel No.3 (RP3) to

specification GB 6537-94 at all major International airports which meets International

Specifications including ASTM D1655 for Jet A-1.

11.3 Russian and C.I.S. Aircraft Operation on High Flash Fuel.

Russian aircraft and engines have not been designed to operate on high flash fuel.

Impacts on their operability and airworthiness have not been determined.

In the past they have experienced problems operating on Jet A from the U.S. and Merox

treated fuels resulting in lacquering of engine components.

11.4 Changing the Experience Database

The aviation fuel community is by nature very conservative. It has a high confidence

level with currently produced fuel because of a long experience base. Collectively, we

cannot readily measure the existing margin to alter the nature of the fuel for all aircraft

engine types. Effects from changes at a single source are difficult to determine because

they are usually lost in the pool fuel volume, so that continuous operation at the extremes

of the property limits is infrequent. Conversely, changes to the jet fuel pool as a whole

must of necessity be viewed with concern. The concern level for a change in minimum

flash point to 110-120oF is significant. The concern level for a change to 140oF is many

times higher because refiners can be expected to change production methods and reduce

specification margins on a broad scale.

Possible mitigating actions to off-set adverse effects on engine and APU operation might

include hardware modifications, adjustments and re-calibrations. There is a potential that

increased viscosity may require measures to moderate low temperature extremes in the

APU environment, or a change in the viscosity requirement. Other revisions of fuel

specification requirements might be necessary in addition to the increase in flash point,

and aircraft operational limits might require consideration. The current effort has not

included evaluation of impact on availability from other possible specification changes.

Conceptually, an increase in only the flash point should not markedly affect the

properties or suitability of jet fuel for its intended purpose. Some high volatility

components would be eliminated to increase flash point, and some low volatility

components would be eliminated to assure jet fuel still meets freezing point requirements.

Thus it would appear that all of the fuel would remain within the criteria bounded by the

previous requirements. This view, however, is an over-simplification. API review (see
Report of Task Group 6/7 on Fuel Properties

71

Section 9.2.1.1) of likely changes indicates the propensity to produce fuel with properties

and molecular composition outside current experience increases significantly with

increasing flash point requirements. This raises concerns about departure from current

engine and APU test and service experience for key specification limits and actual

property values in the population. This is true for individual key properties and

combinations thereof.

The vast majority of the world’s airline fleet operates on a varied diet of jet fuels as they

refuel at each destination. Major destinations in turn receive their fuel from more than

one refinery. Because most planes are exposed to an “average” diet of fuels, they

experience an averaged exposure to fuel property extremes. Changes to flash point are

likely to cause drift for several fuel properties, especially viscosity at low temperature,

aromatics content, thermal stability, and smoke point.

Jet fuel properties are largely determined by four variables: the initial and final boiling

points (together these define the boiling range), processing, and the type of crude oil

feedstock. Currently, nearly all jet fuel is either a boiling range fraction from the crude

oil distillation column (with further mild processing to improve properties without

significantly changing the hydrocarbons present) or a mixture of this fraction with

hydrocarbons of a similar boiling range obtained from a hydrocracking unit. Use of

hydrocracker component is more recent, and was introduced slowly; a few jet fuels now

contain only this component but most of the time it is blended with the kerosene boiling

range product from crude distillation.

A complex issue for further consideration, however, is that changes to increase the

minimum flash point may cause abrupt shifts in refinery process components which are

used to make up jet fuel, to maintain the current product volume. The motivation for

such shifts is proportional to the increase in minimum flash point. At 110-120F,

motivation would be light to moderate for Jet A production in the U.S., and moderate for

Jet A-1 elsewhere. At 140oF flash point pressure to include non-conventional streams

would be strong in the U.S., and can only be described as extreme elsewhere. Stated

differently, at a 140oF flash point a large enough proportion of jet fuel refiners could be

expected to include presently atypical components that the pool composition of fuel could

be changed outside of the current experience base.

For example, a component with a similar boiling range to kerosene can be obtained from

a fluid catalytic cracking unit, present on most refineries. This material is not normally

used in jet fuel because it has poor thermal stability, very high aromatics content and very

low smoke point. It can be expected that many refiners will need to produce at the

extremities of the specification by including such marginal streams, to meet fuel demand.

This will result in a reduction of the margin for these properties in the overall jet pool,

proportional to the increase in flash point.

Overall, at the extremes of contemplated flash point increases, such changes have a

characteristic unparalleled in aviation fuel history. Up until now, changes in fuel

composition and properties could be described as carefully measured and controlled,
Report of Task Group 6/7 on Fuel Properties

72

slowly evolving over time. Changes brought about by a significant change in minimum

flash point, it is feared, are likely to be rapid and uncontrolled, driven by urgent needs to

make up shortfalls in product volume, especially at refineries maximizing jet fuel

production. In the past, small adjustments have been agreed to after lengthy debate and

after gathering data on the suitability of the revised fuel specifications. For example, the

maximum freezing point of Jet A-1 was changed from –50o to –47oC after several years

of in-flight measurements and development of detailed climatic data. Maximum

aromatics content of fuel has slowly increased from a maximum of 20% to 22% to 25%

over a period of years, during which time refiners were required to report to customers

when fuels had aromatics content higher than 20% (later 22%). Inclusion of small

volumes of Fischer-Tropsch liquids sparked healthy debate and investigations over a

period of two years that have not yet been concluded.

Most of the jet fuel was totally unaffected by these changes, but by expanding the

envelope of allowed properties slightly, adequate fuel supplies were assured in select

areas. The average effect on jet pool quality was minor, and difficult to measure.

Because the increase in flash point will, for the first time, significantly restrict

availability, nearly all refiners, rather than a few, will be changing their production

methods and thus the properties of the most of the jet fuel pool could be modified.

Again, the magnitude of these changes is proportional to the change in minimum flash

point.
Report of Task Group 6/7 on Fuel Properties

73

12.0 COST AND AVAILABILITY IMPACT OF HIGH FLASH JET FUEL

 The API/NPRA survey results are included as Appendix 1. Seventy-eight refiners

completed the survey, which represented nearly 87% of the refining crude capacity and

practically 100% of jet fuel production, based on Department of Energy (DOE) weekly

production figures.

The survey was designed to assess the industry's ability to manufacture jet fuel with a

higher flash point and estimate the impact on manufacturing costs associated with a range

of property changes. Respondents were asked to complete a questionnaire for each

refinery in which they currently produce commercial aviation Jet A fuel. The first

question requested general information regarding the capacities of each refinery. The

second set of questions (2a through 2g) assumed a series of revised minimum flash points

and asked the respondents to determine:

a. Changes in jet fuel production volume

b. Total short term cost resulting from potential specification changes

c. Other product volume reductions or increases

d. Amount of reduction from (a) that could be made up in the short term

e. Total cost in (d) resulting from potential specification changes

f. Capital investments to make up as much of the lost production as

 feasible

g. Total cost of long term changes in (f) to recover this jet fuel

 production

The third set of questions (3a through 3g) assumed a series of revised minimum flash

points and a reduction of the freeze point minimum specification as a basis for

determining the same information (a through g) as above. The fourth question asked

whether any of the changes to the flash point specification would create difficulties in

complying with gasoline parameters.

The API/NPRA Survey was also distributed internationally. Survey responses from 33

European refineries were submitted by EUROPIA, the European Petroleum Industry

Association (Appendix 2) representing more than two thirds of the jet fuel production and

50% of the crude distillation capacity in Europe. The Petroleum Association of Japan

also submitted data from 24 refineries representing 85% of the jet fuel production and

72% of the crude distillation capacity in Japan (Appendix 3).

All survey results address jet fuel demand at 1998 levels. The survey does not address

long-term changes in jet fuel demand or changes that could result from environmental

regulations on other fuels. However, increases in demand or environmentally driven fuel

changes are likely to amplify the difficulties predicted for the 1998 level (see Section

12.2.4).
Report of Task Group 6/7 on Fuel Properties

74

Further, anticipated growth in jet fuel demand will put pressure on jet fuel availability

even without a flash point change. Any increase in flash point will further complicated

this situation.

12.1 Fuel Cost Estimates

All cost estimates reported are the estimated manufacturing costs to produce the new

fuels. The actual price for these fuels will be set by the marketplace. In addition, refiners

reported that these costs do not provide for 100% replacement of jet fuel production lost

as a result of the higher minimum flash points (see Section 12.2).

12.1.1 United States

The API/NPRA survey results indicated that requirements for higher flash point jet fuels

could result in United States refinery short-term (up to 24 months) production cost

increases of 2-3 cents per gallon at 120 degrees F up to 5-7 cents per gallon at 150

degrees F. These short term costs do not include capital investments, but include

incremental operating costs and economic losses through downgrades or changed

product slates.

Long-term (up to five year) cost estimates, which include potential capital investments,

ranged from 1.5-2.2 cents per gallon at 120 degrees F to 6-7.5 cents per gallon at 150

degrees F. Long term costs assumed 1998 dollars, 7% ROI for capital investment

decisions and 10% return on capital. Based on current U.S. jet fuel demand, this

translates into annual costs of $350-520 million at 120 degrees F to $1.4-1.7 billion at

150 degrees F.

U.S. refiners estimate their required capital investment to produce 120 degree F jet fuel at

about $3 billion up to about $9 billion for 150 degree F fuel.

12.1.2 Europe

The EUROPIA survey results indicated that the requirements for higher flash point jet

fuel could result in European refinery short-term (up to 24 months) production cost

increases of 9 cents per gallon at 120 degrees F to more than 15 cents per gallon at 150

degrees F. Long term cost increases were 8 cents per gallon at 120 degrees F to more

than 20 cents per gallon at 150 degrees F. European refiners estimate their capital

investment to produce 120 degree F jet fuel at about $5 billion for 120 degree F fuel up to

over $17 billion for 150 degree F fuel.

EUROPIA indicated that the impact in Europe is greater than the U.S. due to:

• The manufacture of the lower freeze point Jet A-1 grade in Europe which additionally

reduces the potential jet fuel yield on crude;
Report of Task Group 6/7 on Fuel Properties

75

• The demand barrel shape in Europe differs with less motor gasoline and more middle

distillates required from a barrel of crude oil. This tends to produce higher front end

cut points and flash points for U.S. jet fuel;

• Europe has a stronger demand for diesel fuel for which kerosene is also required.

Environmental pressures in Europe are likely to require a lighter diesel fuel

containing more kerosene in the near future.

12.1.3 Rest of the World

Survey results submitted by the Petroleum Association of Japan were consistent with data

submitted by EUROPIA for the three reasons given in 12.1.2. Further, the Japanese

reported that in order to manufacture a new specification of jet fuel, most of their refiners

would have to give up their current refinery slate and install new facilities to produce jet

fuel possibly including hydrocracking units. However, installing new units, or facilities

in Japan is difficult due to space limitations and environmental/safety regulations so their

report concluded that it would be economically infeasible to attempt to recover the lost

volume.

12.2 Availability of Fuel

It was generally agreed that worldwide, higher flash points would result in less

availability of jet fuel, and would require longer lead times for industry to meet demand.

It is impossible to speculate on the future business plans of refiners regarding their

decision to ensure that there would be an adequate supply of jet fuel.

12.2.1 United States

The API/NPRA survey results indicate that requirements for higher flash point jet fuel

will result in U.S. refinery shortfalls of up to five percent at 120 degrees F and up to

approximately 20 percent at 150 degrees F (assuming 1 to 2 years lead time and the

required short term investments are made.). Actual shortfalls will vary considerably by

refinery, season and area of the country.

12.2.2 Europe

EUROPIA reported European refinery shortfalls of 12% at 120 degrees F up to 49% at

150 degrees F (assuming 1 to 2 years lead time).

12.2.3 Rest of the World

Similar to EUROPIA, the Petroleum Industry of Japan reported significant short term

production losses of 26% at 120 degrees F and 67% production loss at 150 degrees F.

They concluded that for reasons discussed in Section 12.1.3, proposed specification

changes would create serious availability effect in Japan, not only on jet fuel, but also

only on household heating kerosene.
Report of Task Group 6/7 on Fuel Properties

76

12.2.4 Future Projection of Jet Fuel Demand

The projected demand for jet fuel needs to be viewed in context with that for other

refined petroleum products, including gasoline, diesel fuel, and fuel oil distillates. If

growth in jet fuel demand is matched by increased demand for other products, there will

be no dislocation requiring increased conversion of the crude barrel to jet fuel, and the

increased demand can be readily absorbed by overall increases in refining capacity.

In the United States, jet fuel demand has grown at a rate of about 1.8 % per year over the

past six years, and was in balance with similar growth in demand for gasoline, diesel fuel,

and fuel oil.1 However, jet fuel demand has been projected to increase 1.7% in 1998,

compared to about 1% higher demand for motor gasoline, and 1.2% increased demand

for other distillate fuels.2

World-wide demand for jet fuel is likely to grow at a rate of about 2.6-4.1% per year.3

The Pacific Rim, Europe, and many other areas outside the United States will show

higher demand growth rates. In the meantime, world-wide refined petroleum product

demand is expected to increase at a rate of just under 2.5% per year.4 On a world-wide

basis, demand growth for jet fuel will likely exceed production of other refined

transportation fuels by about 0.5 to1% each year. Thus by 2010, world-wide demand for

jet fuel is projected to grow 6 to 15% more than other refined petroleum products.

While this appears to be a modest dislocation, other forces are expected to magnify its

importance. The composition of gasoline and diesel fuels is increasingly being

reformulated to reduce environmental impact. These required changes to other fuels will

impact the supply and properties of jet fuel and some of these fuels may in fact compete

directly for the same portion of the barrel. For example, the rate of growth of diesel fuel

is high in Europe, and regulations may require greater use of “light” diesel fuels, which

compete for the jet fuel portion of the barrel.5

References

1

 Oil and Gas Journal, week of December 29, 1997.

2

 Oil and Gas Journal, week of January 26, 1998.

3

 ICAO Journal, March 1996, p 9.

4

 SN Crewson, “Oil Markets – Industry Supply and Demand Dynamics”, presented at the

IATA Fuel Trade Meeting, Prague, May 7/8, 1997.

5

 EUROPIA report to the ARAC Task Group 6/7, Atlanta, April 15/16, 1998.
Report of Task Group 6/7 on Fuel Properties

77

12.2.5 Local Situations

From the beginning, members of Task Group 6/7 expressed concerns about the possible

reduction of jet fuel supply at some airports if flash point was raised significantly,

possibly resulting in localized shortages. Unfortunately the formal surveys by EUROPIA

and API, to avoid anti-competitive practices, provided only broad area pictures of how

fuel availability would be effected by changes in the minimum flash point requirements.

A few non-petroleum company members of Task Group 6/7 carried out a confidential,

informal survey in cooperation with a few U.S. and international airlines, to better define

localized supply and demand imbalances, which might result from minimum flash point

changes. This effort was not highly successful, mainly because it was not possible to fully

develop an overall view of alternate supply feasibility for various airports.

In this survey, airlines asked their suppliers to advise the immediate impact of a change in

flash point, and did not request information on recovery of lost capacity (if any).

While it was generally not possible to define effects on specific airports, a review of the

responses by individual suppliers revealed tremendous variation in the impact on supply.

Availability from a few refiners was unaffected by minimum flash point requirements of

120 or 130oF. Others were significantly affected at these levels. Thus flexibility of

refiners to adapt varied markedly. In addition, those refiners known to be currently

maximizing the yield of jet fuel universally suffered significant production losses.

Results of the survey also indicated that refiners generally assumed that the current

freezing point requirements for their area would remain in place.

An informal Australian/New Zealand survey encompassed all nine refiners in that region.

The data again showed significant variation from refinery to refinery. Currently, supply

availability and demand are in balance. However, demand for jet fuel has been growing

in this area at a rate of 4-5% for the past ten years, while demand for gasoline has been

growing at a rate of 1-2%. Refiners were predicting difficulties in meeting jet fuel

demand during the next several years, even prior to the high flash jet fuel initiative. Data

are shown below in Section 12.2, Table 1 below. These data show immediate impact

without investment or other changes to improve jet fuel production, and in general

assume the fuel supplied would be Jet A-1 fuel with a maximum freezing point of –47oC

(-53oF).

Flash Point 49C 54C 60C 65C

Region I 10-30% 45-50% >50% >50%

Region II 5-10% 10-40% 20-50% 20-100%

Region III 5-50% 5-50% 20-100% 20-100%

Region IV 5-50% >50% >50% >50%

Region V 20-30% >50% >50% 100%

Section 12.2.5, Table 1. Percent Reduction in Australian/New Zealand Jet Fuel

Availability at Higher Flash Points
Report of Task Group 6/7 on Fuel Properties

78

12.3 Impact of Availability on Price

Note: The American Petroleum Institute, EUROPIA and member companies did

not participate in the analysis in Section 12.3 and do not endorse any conclusions,

stated or inferred regarding such impacts.

The proposed flash point changes for jet fuel will increase the cost of production and

shrink the available capacity to produce the fuel. Just like any commodity these events

will both impact the market price for jet fuel. The extra production costs will raise the

market price to the extent the market follows perfectly competitive marginal cost pricing

behavior. Given the industry survey results, the cost increase may have some upward

price repercussions. The reduction in capacity will create a temporary shortage of jet fuel

that will be relieved only when the capacity has been added by the industry. Increasing

the capacity will take approximately two years. The capacity shortage has the potential

for substantial price increases until the capacity constraint is lifted.

Price elasticity models are used to predict the impact of a decrease in quantity, to the

price of a commodity, relative to the demand. For this analysis, we did not assign a

specific price elasticity to jet fuel, but we can assume that it is likely very inelastic.

Inelastic demand means that the quantity demanded will decrease by less than one

percent given a one percent increase in price. A price elasticity of .5 means that a onepercent increase in price will lead to a .5% reduction in quantity.

To demonstrate what possible outcomes would be given a range of possible price

elasticities, we calculated the increases in price that could occur for various combinations

of capacity reductions and price elasticities. Also for this analysis we assume no

substitutions exist for jet fuel. In other words, we have assumed that the consumers

would not be able to switch to another petroleum product such as diesel as the jet fuel

price increased.

As Table 1 demonstrates, the possible potential impact on price from capacity constraints

is dramatic. The price increases will be more substantial the greater the capacity

reduction as a result of higher flash points, or the more inelastic the demand for jet fuel.
Report of Task Group 6/7 on Fuel Properties

79

Cost impact of higher jet fuel flash points

Higher prices due to lowered capacity

Percentage price increase due to capacity reduction

Capacity Price elasticity for jet fuel market

Flash Reduction 1.0 0.8 0.6 0.4 0.2

120 8.11% 8.11% 10.14% 13.52% 20.28% 40.55%

130 16.74% 16.74% 20.93% 27.90% 41.85% 83.70%

140 24.72% 24.72% 30.90% 41.20% 61.80% 123.60%

150 32.13% 32.13% 40.16% 53.55% 80.33% 160.65%

note: % change in price = % change in quantity / price elasticity*

Base price per gallon: $0.50

 Price increase due to capacity reduction

Capacity Price elasticity for jet fuel market

Flash Reduction 1.0 0.8 0.6 0.4 0.2

120 8.11% $0.04 $0.05 $0.07 $0.10 $0.20

130 16.74% $0.08 $0.10 $0.14 $0.21 $0.42

140 24.72% $0.12 $0.15 $0.21 $0.31 $0.62

150 32.13% $0.16 $0.20 $0.27 $0.40 $0.80

 Base quantity consumed: 23 (Billion gallons)

Years until capacity added: 2

 Cost of flash point increase until capacity added

Capacity Price elasticity for jet fuel market

Flash Reduction 1.0 0.8 0.6 0.4 0.2

120 8.11% $1,714,024,170 $2,142,530,213 $2,856,706,950 $4,285,060,425 $8,570,120,850

130 16.74% $3,205,676,520 $4,007,095,650 $5,342,794,200 $8,014,191,300 $16,028,382,600

140 24.72% $4,280,119,680 $5,350,149,600 $7,133,532,800 $10,700,299,200 $21,400,598,400

150 32.13% $5,015,525,130 $6,269,406,413 $8,359,208,550 $12,538,812,825 $25,077,625,650

Section 12.3, Table 1—Impact of Availability on Price
Report of Task Group 6/7 on Fuel Properties

80

Notes:

1. Costs are not adjusted for inflation

2. Costs are calculated using only the gallons still purchased. This analysis does not include any indirect

costs of using alternates to jet fuel and air travel.

3. These costs also do not include the additional costs of the fuel once the capacity has been added to

relieve the capacity constraint.

4. This analysis ignores growth in demand for jet fuel that would occur over the time period observed.

* Carlton, Dennis W., and Perloff, Jeffrey M., Modern Industrial Organization, 2nd Edition, Harper

Collins College Publishers, 1994.

12.4 Effects on Crude Oil Selection

An increased jet fuel flash point specification may impact the market for crude oils. The

mechanism of impact is complex and effects cannot be predicted at this time.

The issue is that crude oils differ with respect to the amount of jet fuel that they produce

at higher flash points. To illustrate this, the coded individual crude oil results from the

Jet Fuel Properties Survey (Section 9.2.1, Table 1) were used to make Section 12.4 ,Table

1 for Jet A [-40°F (-40°C) freeze point] and Section 12.4, Table 2 [-53°F (-47°C) freeze

point]. The Tables show the percentage of the base case [100°F (38°C) flash point

specification and -40°F (-40°F) freeze point] that the crude oil could produce at higher

flash point specification values. The Tables indicate only “Avail” (jet fuel produced) and

“Not Avail” (no jet fuel produced) for the three crude oils (B, N and D) where only

qualitative data were supplied.

Coded

Crude

100°F 110°F 120°F 130°F 140°F 150°F

L 100 96 92 87 83 79

J 100 94 89 83 78 72

E 100 94 89 83 78 72

G 100 90 79 69 59 48

I 100 87 74 61 49 36

O 100 89 76 63 49 36

A 100 87 74 60 47 34

H 100 84 67 51 35 18

K 100 86 73 59 45 31

F 100 81 62 43 24 5

C 100 77 54 31 8 0

M 100 72 43 15 0 0

B Avail Avail Avail Avail Avail Avail

N Avail Avail Avail Avail Avail Avail

D Avail Avail Avail Avail Not Avail Not Avail

Section 12.4, Table 1-- Relative Jet A yields (%) at selected flash point specification

values from the Jet Fuel Properties Survey.
Report of Task Group 6/7 on Fuel Properties

81

Coded

Crude

100°F 110°F 120°F 130°F 140°F 150°F

L 81 76 70 65 60 54

J 74 69 63 57 52 46

E 69 64 58 52 47 41

G 85 73 62 50 38 27

I 85 69 52 35 18 1

O 77 60 44 28 11 0

A 79 60 40 21 1 0

H 67 47 27 7 0 0

K 65 44 24 4 0 0

F 60 41 22 4 0 0

C 60 41 22 4 0 0

M 43 6 0 0 0 0

B Avail Avail Avail Not Avail Not Avail Not Avail

N Avail Avail Avail Avail Not Avail Not Avail

D Avail Avail Avail Avail Not Avail Not Avail

Section 12.4, Table 2-- Relative Jet A-1 yields (%) at selected flash point

specification values from the Jet Fuel Properties Survey

The results show that, for the representative crude oils evaluated here, jet fuel production

by distillation is greatly reduced at the higher flash point specification values for a

number of crude oils.

The impact of this is that if the flash point specification is increased enough to affect

availability that:

• The demand may increase for crude oils having higher jet fuel yield coupled with

reduced demand for other crude oils.

• Refineries and localities having little flexibility concerning crude oil source may be

impacted significantly better or worse than average.

12.5 Effect on Refining

The impact on the manufacturing cost of other fuels (gasoline and diesel) of a higher

minimum flash point was not assessed.

The API/NPRA survey results indicate that, as the minimum flash point increases, more

refiners could have difficulty producing gasoline and diesel that complies with current

state and federal environmental regulations. This impact would be particularly severe in

California and the East Coast (PADD 1), where the refiners surveyed reported that even

raising the jet fuel flash point to 120°F could severely affect their ability to comply with

the aromatics and distillation requirements for gasoline.
Report of Task Group 6/7 on Fuel Properties

82

12.6 Effect on APU Cost

If the fuel flash point is increased over current levels, addition of a fuel heater at the APU

inlet may be required to ensure reliable APU starting for all ambient conditions.

The rough order of magnitude (ROM) cost to develop and certify a direct current (DC)

powered APU fuel heater with BITE (Built in Test Equipment) was estimated to be up to

$1M per APU model. Approximately 24 months would be required for development and

qualification prior to delivery to the aircraft manufacturer. The reoccurring cost was

estimated to be approximately $10,000 per engine, with an increase of approximately 4

lb. in APU weight. An additional 12 to 24 months would be required to incorporate the

fuel heater in the field. The operator maintenance time to add the fuel heater and

implement other necessary changes is estimated to be approximately 8 hours.

Additional time and cost would be required to complete any aircraft modifications or

flight-testing required. Aircraft changes that may be required include wiring from the

APU to the electronic control unit (usually located in a different compartment),

modifications to the flight deck display, modifications to the APU battery or charger,

modifications to the main engine generators, modifications to aircraft operational

procedures, and any airplane manual revisions.

Additional recurring and non-recurring costs would be involved if an alternating current

(AC) powered fuel heater were employed.
Report of Task Group 6/7 on Fuel Properties

83

13.0 BIBLIOGRAPHY

This Section was not used.
Report of Task Group 6/7 on Fuel Properties

84

14.0 APPENDIXES

14.1 Final Report API/NPRA Aviation Fuel Properties Survey

14.2 EUROPIA Effect of Jet A-1 Flash Point on Product Availability and

Properties

14.3 PAJ Impacts of Jet A-1 Flash Point Changes

14.4 Fuel Property Effects on Engines (Section 9.3.2, Table 1)

14.5 Estimate of Ten-Year Cost of Fuel Change

***




















































































APPENDIX --- Section 14.5 --- Estimate of Ten-Year Cost of Flash Point Change for Jet Fuel

 In drafting the Executive Summary of the FTHWG Report (see request at end of this note), the “TenYear” Cost of the various Technology Options was estimated. For Flash Point Changes, the attached

spreadsheet was constructed to estimate the cost of a Flash Point Change.

 The estimate is straightforward based on the annual-cost information in the API/NPRA and EUROPIA

Surveys (Sections 14.1 and 14.2). These annual-cost information (basically the Answers to Survey

Question 2g) include “incremental operating costs, capital charges and any economic losses through

downgrades of changed product slate in cpg over the full volume of jet fuel produced.” Therefore the

spreadsheet displays the “Ten-Year” Cost for different “annual-cost” cpg numbers. Per the attached

request, the “Ten-Year” Cost can be for Jet Fuel Volume with / without a growth rate (ex. is 3.5%).

 If, in response to a Flash Point Change from 100F->120F, the Annual-Cost ( for 7% ROI) was 2 cpg

for U.S. Jet Fuel (with 1.6 Million Barrels/Day) and 8 cpg for Rest-of-World Jet Fuel (with 2.1 Million

Barrels/Day) ::

...the no-growth “Ten-Year” Costs are $ 4.9 Billion + $25.8 Billion Ë $30.7 Billion

 ( with 3.5% growth Ë $38.0 Billion)

 Different Volumes and cpg numbers can be estimated by simple interpolation/extrapolation of the

values in the tables ...or ... by simple calculation using the selected cpg number and volume for gallons/

ten-years.

==================================================================

==== Question from Ivor Thomas for "FTHWG Overview Report / Summary" ====

==================================================================

From: Thomas, Ivor[SMTP:Ivor.Thomas@PSS.Boeing.com]

Sent: Thursday, July 02, 1998 10:21 AM

To: Lieder CA (Chuck) at MSXWHWTC

Subject: Question about "Deltas / Increases" in Cost of Jet Fuel

Chuck, thanks for the input. On another subject: In order to do a cost benefit analysis we are

trying to estimate the US and World fleet cost to implement the various solutions over a

ten year duration. This would include cost of design and installation and running costs for

ten years. We haven't got enough to time worry implementation schedules. If I look at the

120 Flash Fuel, can you project out a ten year cost to the airlines. Oren did a quick look which

assumed a straight $.02/gal (US) and $.08/gal (Rest of the World) and a 3.5% pa growth rate.

This comes to $4.6B for US and $12.4B for Rest of the World. Is there any logic to assume the

 $.02/gal would come down over time as the refineries use the added capability to make more

profit on other components and as the cost gets lost in the overall price Competition.

 ...from Ivor Thomas

==================================================================
Ten-Year Cost Estimates

Some Cost Estimation of Jet Fuel SCENARIOs

....Assumptions.... MB/D Gallons/D Gallons/Yr Quickie Results.... DELTA CO$T "Summary" ...with Vol Increase ...No Vol Increase

if US => 2 cpg ; WorldWide => 8 cpg $35,968,451,430 $30,660,000,000

U.S. Jet Fuel Use 1.60E+06 6.72E+07 2.45E+10

if US => 2 cpg ; WorldWide => 5 cpg $24,638,389,230 $21,002,100,000

Rest-of-World Use 2.10E+06 8.82E+07 3.22E+10 if US => 3 cpg ; WorldWide => 8 cpg $38,845,927,545 $33,112,800,000

============================================================================================================================================================== =========================================================================================

U.S. Jet Fuel Use Delta CO$T = 1 cpg 2 cpg 3 cpg 4 cpg 6 cpg

Volume Increase from ZERO Year

Year ZERO 0 $245,280,000 $490,560,000 $735,840,000 $981,120,000 $1,471,680,000

ONE 3.5 $253,864,800 $507,729,600 $761,594,400 $1,015,459,200 $1,523,188,800

TWO 7.1 $262,750,068 $525,500,136 $788,250,204 $1,051,000,272 $1,576,500,408

THREE 10.9 $271,946,320 $543,892,641 $815,838,961 $1,087,785,282 $1,631,677,922

FOUR 14.8 $281,464,442 $562,928,883 $844,393,325 $1,125,857,766 $1,688,786,650

FIVE 18.8 $291,315,697 $582,631,394 $873,947,091 $1,165,262,788 $1,747,894,182

SIX 22.9 $301,511,746 $603,023,493 $904,535,239 $1,206,046,986 $1,809,070,479

SEVEN 27.2 $312,064,658 $624,129,315 $936,193,973 $1,248,258,630 $1,872,387,945

EIGHT 31.7 $322,986,921 $645,973,841 $968,960,762 $1,291,947,682 $1,937,921,524

NINE 36.3 $334,291,463 $668,582,926 $1,002,874,388 $1,337,165,851 $2,005,748,777

=TOTAL= =TOTAL= $2,877,476,114 $5,754,952,229 $8,632,428,343 $11,509,904,458 $17,264,856,687

TOTAL...if no Growth ---> $2,452,800,000 $4,905,600,000 $7,358,400,000 $9,811,200,000 $14,716,800,000

Rest-of-World Use Delta CO$T = 3cpg 5 cpg 8 cpg 10 cpg 15 cpg

Volume Increase from ZERO Year

Year ZERO 0 $965,790,000 $1,609,650,000 $2,575,440,000 $3,219,300,000 $4,828,950,000

ONE 3.5 $999,592,650 $1,665,987,750 $2,665,580,400 $3,331,975,500 $4,997,963,250

TWO 7.1 $1,034,578,393 $1,724,297,321 $2,758,875,714 $3,448,594,643 $5,172,891,964

THREE 10.9 $1,070,788,636 $1,784,647,727 $2,855,436,364 $3,569,295,455 $5,353,943,182

FOUR 14.8 $1,108,266,239 $1,847,110,398 $2,955,376,637 $3,694,220,796 $5,541,331,194

FIVE 18.8 $1,147,055,557 $1,911,759,262 $3,058,814,819 $3,823,518,524 $5,735,277,786

SIX 22.9 $1,187,202,502 $1,978,670,836 $3,165,873,338 $3,957,341,672 $5,936,012,508

SEVEN 27.2 $1,228,754,589 $2,047,924,315 $3,276,678,904 $4,095,848,631 $6,143,772,946

EIGHT 31.7 $1,271,761,000 $2,119,601,666 $3,391,362,666 $4,239,203,333 $6,358,804,999

NINE 36.3 $1,316,272,635 $2,193,787,725 $3,510,060,359 $4,387,575,449 $6,581,363,174

=TOTAL= =TOTAL= $11,330,062,201 $18,883,437,001 $30,213,499,202 $37,766,874,002 $56,650,311,003

TOTAL...if no Growth ---> $9,657,900,000 $16,096,500,000 $25,754,400,000 $32,193,000,000 $48,289,500,000

 Scenarios for Estimates => U.S. +1 / W +3cpg U.S. +2 / W +5cpg U.S. +3 / W +8cpg U.S. +4 / W +10cpg U.S. +6 / W +15cpg

= WorldWide TOTAL = = WorldWide TOTAL = $14,207,538,315 $24,638,389,230 $38,845,927,545 $49,276,778,460 $73,915,167,689

TOTAL...if no Growth ---> $12,110,700,000 $21,002,100,000 $33,112,800,000 $42,004,200,000 $63,006,300,000

Page 1
Ten-Year Cost Estimates

============================================================================================================

Page 2
Evaluation Standards and

Proposed Regulatory Action

Advisory Group

Task Group 8

Aviation Rulemaking

Advisory Committee

ARAC

JAA FAA

THE PUBLIC
14th July, 1998

1

1. Background

Task Group # 8 had two objectives;

1, Provide a common set of definitions to the other Task Groups so there

was consistency in the data used by all groups, and

2, Define Proposed regulatory Action

2. Summary

2.1 Objective 1,

Technical support was provided to all TG’s in the form of generic airplane definitions and

missions for use in assessing potential safety enhancements. A spreadsheet was developed

to provide a common source of data to be used by the task groups in order to ensure that

the potential methods were evaluated using consistent data and assumptions. Data were

included in the spreadsheet for six generic airplane types: small, medium and large

transports, regional turbofans, regional turboprops and business jets. The data included

summaries for each airplane type, such as fleet size, weights, fuel volumes and flight

distributions. Mission profile data such as weight, altitude, Mach number, fuel remaining

in each tank and body angle as a function of time was included for each generic airplane

type. Temperature profiles ranging from cold to extremely hot were also included in the

mission profiles. Performance trades and cost trades were also included to allow the

consistent calculation of performance and cost impacts.

2.2 Objective 2,

A proposed change to FAR 25 has been drafted together with the body of a supporting

Advisory Circular. The intent of the proposed regulatory action is to create a revised FAR

25.981 which will have two sections, the first addressing ignition source prevention in fuel

systems, and the second part addressing controlling the flammability exposure within fuel

tanks. The first part of the proposed FAR 25.981 will be addressed by the FAA directly

and is outside the TOR for the FTHWG. The intent of the second part of the proposed

FAR is to require that either the exposure of any tank to flammable fuel air mixtures be no

greater than 7 % of fleet operational time, or that protective systems be provided for tanks

that can not meet the flammability requirement. The requirement for flammability control

is based on the fleet history as provided by TG1 coupled with the flammability exposure

for the current fleet being provided by TG5. The other task groups have defined methods

to satisfy the requirements of the proposed regulation and provided costs of

implementation. Task Group 8 developed the proposed regulatory action and supporting

AC/ACJ to allow the other groups to develop and cost different means to satisfy the

proposed regulation. The cost benefits of each proposed means must be examined by the

FTHWG to determine if a suitable means to satisfy the regulation exists and should such a

regulation be proposed.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

2

The supporting AC material is drafted to provide the methodology for assessing any given

tank against the proposed rule, and will incorporate information on what alternatives are

available to the applicant to satisfy the requirement. This section includes information on

Foam, Inerting, Higher Flash Point Fuel etc.
14th

Task Group 8, Standards and Proposed Regulatory Action

3

3.1 Objective 1, Generic Standards

Technical support was provided to all TG’s in the form of generic airplane definitions and

A spreadsheet was developed

to provide a common source of data to be used by the task groups in order to ensure that

included in the spreadsheet for six generic airplane types: small, medium and large

transports, regional turbofans, regional turboprops and business jets. The data included

volumes and flight

in each tank and body angle as a function of time was included for each generic airplane

type. Temperature profiles ranging from cold to extremely hot were also included in the

consistent calculation of performance and cost impacts.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

4

3.2 Objective 2, Proposed Regulatory Action

In order to enhance fuel system safety, the task group 8 recommended to the FTHWG

that the following regulation be proposed to the FAA/JAA provided that the cost benefit

studies show a net gain to the aviation system:

Create a revised paragraph FAR 25.981 to address fuel tank protection from airplane

created threats that could prevent continued safe flight and landing. The proposed revision

is as follows:

Section 25.981 Fuel Tank Ignition

Prevention

 The fuel system must be designed and

arranged to prevent the ignition of fuel

vapor within the tanks, or mitigate the

effects of such an ignition by addressing:

(a) Ignition Sources

(a)1. Place the current 25.981 requirement

here

(a)2. Additional requirements in ignition

source mitigation as defined by the

FAA would be in section (a)2, (a)3, etc.

as defined by the SFAR effort underway

(b) Flammable Vapors

Limit the development of flammable

conditions in the fuel tanks, based on the

intended fuel types, to less than 7% of the

expected fleet operational time, or

Provide means to mitigate the effects of an

ignition of fuel vapors within the fuel tanks

such that any damage caused by an

ignition will not prevent continued safe

flight and landing.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

5

3.2.1 Discussion on the intent of the proposed requirement

The proposed regulatory action provides a single regulation to address ignition prevention,

thereby avoiding having several paragraphs which must be linked and interpreted in

conjunction with each other. It provides the industry with a requirement that addresses all

aspects of fuel tank ignition prevention/mitigation, which can be treated as a

comprehensive requirement and addressed as one issue. The existing requirements set

forth in sections 25.901, 25.954 and 25.981 are intended to preclude ignition sources from

being present in airplane fuel tanks. As proposed, Paragraph (a) maintains these

requirements, which have been, are, and shall continue to be, the essential primary

elements in fuel tank safety. Paragraph (b) provides a requirement to address flammability

mitigation as a new layer of protection to the fuel system. The intent of the combined

regulation is to prevent an applicant relying solely on ignition prevention or on

flammability reduction as the means to protect the fuel system from ignition events.

It is considered that there should be some ability on the part of the applicant to trade

improvement in ignition prevention for relief in flammability reduction, but only in specific

cases, for example, where the applicant had taken steps to significantly reduce potential

ignition sources such as designing a tank with no pumps or a non electric gauging system.

The Concept of flammability exposure as a “Percentage of Expected Fleet Operational

Time” is a measure of how much time will a given tank, in a fleet of a specific airplane

type, be operating within the flammable range, as determined by the fuel properties and

fuel temperature in that tank. This measure determines the likelihood of an ignition

occurring in a tank that contains a flammable mixture. This is based on the hypothesis that

ignition events occur very infrequently and randomly in any tank of a given airplane type

and thus ignition is dependent on the flammability probability. The “less than 7% of the

expected fleet operational time”, used in Section (b) is derived from examination of the

current fleet exposure, as reported by Task Group 1, which indicates that wing tanks are

statistically less likely to be involved in events than center wing tanks. Task Group 5,

corroborated the fleet history by providing analysis to show there is a significant difference

in fleet average exposure to flammable conditions between wing tanks (2% to 6% ) and

center wing tanks with nearby heat sources (approximately 30% ). Using this data it was

concluded that a 7% fleet average exposure would provide a significant improvement in

safety without unduly penalizing current tanks without heat sources in, or nearby the tank.

The combination of ignition source control, which is currently being upgraded through the

SFAR activity, and flammability control will provide fuel systems whose exposure to a

catastrophic event is much improved over today’s high standards.

Section (b) implicitly includes the option of using inerting of some form, or higher flash

point fuel, to satisfy the 7% criterion, and for the use of foam, or explosion protection

means, to satisfy the intent of mitigating the effects of an ignition in a tank where a

designer chooses to use that option.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

6
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

7

3.3 Supporting AC/ACJ Material

The wording below represents the proposed body of an AC/ACJ to support the proposed

new FAR 25.981(b). The AC/ACJ in support of the proposed FAR 25.981(a) is a separate

AC/ACJ and must be developed by the FAA/JAA either in house, or through a new

Harmonization Working Group.

It should be noted that the AC/ACJ material includes two methods of assessing fuel tank

flammability. The second method was developed late in the task group’s efforts and has

not been as thoroughly developed as the first method. Additional testing of the method is

required to validate it prior to adoption within the AC/ACJ.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

8

AC/ACJ 25.981(b)

1 - Purpose

This ACJ sets forth an acceptable method of compliance with the requirements of

FAR/JAR 25.981(b). The guidance provided within this AC is harmonized with the US

Federal Aviation Administration (FAA) and Joint Aviation Authority (JAA) and is

intended to provide a method of compliance that has been found acceptable. As with all

ACJ material, it is not mandatory and does not constitute a regulation.

2 - Applicability

This ACJ applies to part 25 airplanes for which a new, amended, or supplemental type

certificate is requested.

3 - Related Documents

FAR/JAR 25.901

FAR/JAR 25.954

FTHWG Report

TBD by FAA

4 - Background

The regulation is intended to provide requirements to reduce the probability of a fuel tank

explosion to an extremely improbable level. The regulation is divided into two parts,

Part (a) dealing with ignition prevention and

Part (b) dealing with fuel flammability limitation and explosion related damage

prevention.

Part (a) is the subject of a separate AC/ACJ.

Part (b) is addressed herein.

25.981(b) requires that either;

the probability of having a flammable fuel vapor/air mixture in a fuel tank is

reduced to an acceptable level,

or

means are used to prevent airplane damage if an explosion is initiated in a tank that

has a higher than acceptable fleet average flammability exposure.

This AC/ACJ provides an acceptable process for determining the fleet average

flammability exposure of a design, and discusses options that may be used to achieve the
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

9

required level, and discusses explosion suppression means that may be used in lieu of

reducing fleet average flammability exposure.

5 - Definitions

- Flammability; The ability for an fuel vapor/air mixture to be ignited when exposed to a

sufficiently energetic source of energy (electrical, such as a spark; thermal, such as a hot

surface; and mechanical, such as two metal parts rubbing together at high speed to

produce sparks).

- Flammability range; The pressure (i.e. altitude) / temperature domain where the fuel

vapor/ air mixture is flammable. The lower flammability limit (lfl), also known as the lower

explosive limit (lel), defines the temperature/ altitude below which the fuel vapor/air

mixture is too lean to burn. The upper flammability limit (ufl) defines the upper part of the

domain, above which the fuel vapor/air mixture is too rich to burn. This domain is

dependent of the type of fuel used.

Lower Flammability Limit; For the purpose of this AC, the lower flammability limit

should be taken to be equal to the fuel flash point (FP) as determined by ASTM D-56 and

corrected for altitude by -1oF per 800ft altitude increase from sea level.

Upper Flammability Limit; For the purpose of this AC, the upper flammability limit

should be taken to be equal to the fuel flash point +70oF, and corrected for altitude by

-1oF per 600 ft altitude increase from sea level.

Note; This simple approach to define lfl and ufl has been taken

in lieu of any conclusive data on flammability versus ignition

energy versus altitude, and the lack of any data on the

probability of an ignition source of a given energy level being

present in a fuel tank if an ignition source were to be present.

(The FAA Document DOT/FAA/AR-98/26 provides further

information on this subject.)

Fuel types; Different fuels are approved for use in turbine powered aircraft. The most

widely used fuel types are JET-A/JET-A1, JET-B (JP-4). For an aircraft, the approved

fuel types are listed in the Airplane Flight Manual (AFM). Each fuel type has its own

properties, those directly related to flammability are flash point and distillation

characteristics. Property differences can occur in a given fuel type as a results of variations

in the source crude oil properties and the refining process used to produce the fuel.

Fuel tank; An aircraft volume containing fuel. Tanks contains both liquid fuel and, in the

ullage space, a fuel vapor/air mixture, with some water vapor depending on the relative

humidity in the tank.

Ullage, or Ullage Space; The volume within the tank not occupied by liquid fuel.

Operational time; The time from the start of preparing the aircraft for flight, ( turning on

the APU/Ground Power, Starting Environmental Control Systems etc.,), through the

actual flight and landing and the time to disembark any payload/passengers and crew.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

10

6 - Design considerations to limit the probability of flammable conditions

Generally, the drivers in limiting the probability of a flammable mixture in the tank are the

fuel type, fuel temperature and any design feature that increases the potential for fuel mists

to be created. Current design practices which reduce the potential for fuel agitation should

be continued. This prevents the flammability range from widening at the lean end because

of the presence of fuel mist, which may be flammable at temperatures well below the flash

point.

Design practices that reduce the overall risk are described within this paragraph of this

ACJ. Airplane designs submitted for evaluation by the regulatory authorities will be

evaluated against these practices.

The intent of the regulation is to limit the exposure to flammable fuel vapor/air mixtures to

a small amount of the operational time for that aircraft type. Analysis has shown that this

exposure needs to be less than 7% of operational time to provide an acceptably low risk

of a fuel tank explosion. Practical design precautions should be used achieve this criterion.

On any one aircraft type, the most effective methods may vary between different tanks,

according to their exposure to the risk. For instance, tanks located in the wings with little

or no heat input from aircraft systems have been analyzed and shown to meet the

regulation, whereas tanks located within the fuselage contours will require more design

attention. Such tanks may have less ability to reject heat to ambient air, both on the

ground and in flight, and might be subject to heat sources from equipment located nearby

in the fuselage such as the air conditioning packs that supply cool air to the cabin. For

tanks that, because of installation location and/or other factors, do not readily meet the

7% flammability exposure criterion of 25.981(b), additional design considerations should

be considered. The following are provide as examples, but are not the only design

solutions that may be proposed;

a- Limiting heat transfer to the tank

The transfer of significant heat quantities into fuel tanks under normal operation

conditions should be prevented to satisfy the requirement. Locating heat producing

systems away from the tanks should be considered. If this is not a practical solution,

controlling heat transfer to the fuel tank should be addressed. Possible technical solutions

are the use of thermal blankets and/or providing ventilation to remove excess heat from

the area near the tank.

b- Fuel tank ullage sweeping

A positive ventilation system may be used to “sweep” the ullage of flammable fuel

vapor/air mixtures at a rate that keeps the ullage lean in spite of a higher than desirable

fuel temperature. This ventilation system may be used as needed to satisfy the requirement

of the regulation, but should address any negative effects such as sweeping unburned

hydrocarbons into the atmosphere. Evidence that the ullage sweeping system does not

leave pockets of flammable fuel vapor-air mixtures within the tank should be provided.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

11

c- Fuel tank inerting

Fuel tank inerting is another way of reducing the flammability exposure within a given

tank. The accepted level for tank inerting is to reduce the oxygen content of the tank

ullage to less than 9%. The applicant may show that inerting is only needed for certain

missions or parts of a mission to bring the tank fuel vapor/air mixture average exposure

down to an acceptable level. Inerting may be achieved be supplying inert gas from onboard storage bottles, holding either gas or liquid inertant, on board inert gas generation

systems (OBIGGS) or from a ground storage system if the tank is inerted only on the

ground. Evidence that the inerting system does not leave pockets of high oxygen

concentration within the tank should be provided. The effect of oxygen evolving from the

fuel during pressure reduction conditions, such as during climb, should be addressed. The

applicant should demonstrate that the added system does not decrease the overall safety of

the aircraft.

d- Higher Flash Point Fuels

The applicant may consider using only high flash point fuels to reduce the flammability

exposure to an acceptable level.

7 Acceptable means to mitigate of the effects of an explosion

An alternative means of satisfying 25.981(b) is to provide a means to protect a tank from

structural and systems damage that could prevent continued safe flight and landing. This

alternative recognizes that an applicant may choose to accept a high flammability exposure

in a given tank and to provide additional protection to extinguish or suppress an explosion

in a tank if an ignition occurs. The following are provide as examples, but are not the only

design solutions that may be proposed;

a- Foam

The use of appropriate foams to fill the fuel tank and thereby control the pressure rise

following an ignition of the fuel vapor/air mixture has been demonstrated by the USAF

and other military forces to be effective, and is in use on several airplane types. The

applicant may use such a foam installation to satisfy the requirement of 25.981(b). The

foam type should be demonstrated to be effective in suppressing explosions to a level

where structural and system damage is prevented.

The applicant should;

 Provide data on the foam, including material, pore size, and intended method for

installing the foam in the tank.

Address the potential for, and the effects of, degradation of the foam, from any

environmental effects and long term aging, on both the airplane and engine fuel

systems

Address the effect of the foam installation on the airplane fuel system, as well as

the APU and engine fuel systems, and
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

12

Develop maintenance procedures to ensure the foam is correctly installed both

initially and when reinstalled, if removed for access to the tank.

Address the effects of the foam installation on fuel system performance , including

engine feed, venting, fueling and defueling including the effect of the foam on

electrostatic build up in the tank.

b- Explosion suppression

The use of a simple flame propagation suppression system has been approved by the FAA

for use in fuel system surge tanks on some commercial transport aircraft. This technology

has not been proven for use inside fuel tanks but may be pursued by an applicant. An

explosion suppression system typically consists of one or more optical sensors which are

capable of rapidly detecting a flame within their field of view, and then the system

commands the release of extinguishing agent from one or more containers sufficiently

quickly to extinguish the fire before a damaging over-pressure can develop. These systems

may be considered for use in fuel tanks to satisfy 25.981(b).

The applicant should consider the following:

1, Do the sensors’ field of view cover enough of the tank volume to effectively recognize

a explosion developing anywhere in the tank?

2, Is the sensor field of view and sensitive affected by the presence of fuel in the field of

view?,

3, Will the release of extinguishing agent in the tank cause an over pressure, particularly if

the agent is released below the fuel surface?.

4 Will failures of the systems cause over-pressure of the tank?

8- Acceptable Means of Determining the Flammability Exposure of a Given Tank.

In service experience indicates that a satisfactory level of safety can be achieved if the

presence of flammable vapors is less than approximately 7% of operational time as

determined by either of the methods set forth below.

Method I

The presence of flammable vapors should be determined independently for each tank.

Within each tank, separate volumes where barriers or walls prevent mixing of the fuel /air

mixtures, should be treated independently to determine the worst case exposure for that

tank.

The analysis should take into account all fuel types for which certification is sought and

listed in the AFM, and the expected usage of each fuel type.
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

13

To ensure that a consistent method and assumptions are used in this process, specific

ground rules have been developed and must be followed by the applicant.

The amount of ground operation time to be included in determining Airplane Operational

Time as defined in this ACJ, should use the following:

Pre-flight Time;

Small airplanes (maximum TOGW equivalent to a 130 passenger airplane or smaller,) = 45

min,

Medium airplanes (maximum TOGW equivalent to a 130 to 300 passenger airplane) =

1 hr,

Large (maximum TOGW equivalent to more than a 300 passenger airplane) = 1.5 hr, and

Post Flight time;

30 minutes after completion of the landing roll landing for all airplanes.

For each tank in the airplane under consideration, the applicant should determine the

exposure to flammable mixtures in the tank as a percentage of operational time for the

expected fleet as follows;

The applicant should develop a computer model of the thermal environment of the tank so

as to calculate the temperature of the fuel in the tank as a function of operational time as

defined above, including normal airplane system usage, and the effects of any heating or

cooling systems operating in or nearby the tank.

This model may be a detailed thermodynamic of all the heat flows into and out of the tank

in question, or may be a simple model based on sufficient flight tests to allow accurate

corrections for outside conditions and internal heat flow changes with flight conditions.

The applicant should define the flammability regions of the certified or proposed fuel types

as a function of altitude and determine the statistical variation of the flammability range

based on known or expected characteristics of the fuel as delivered to the airplane or

airport. The attached figure is to be used for jet A type fuels, and similar data should be

used in considering the use of higher flash point fuels

The thermal model should be used to calculate the total time the fuel in the tank is in the

flammable region as a percentage of the total operational time of each flight, for a

sufficient number of flights over various range flights, in various ambient temperatures and

with a variety of fuel properties within the specifications of the expected fuel types, to

assess the average fleet exposure to being in the flammability region.

The following factors are to be used in determining fleet exposure.

1, The fleet of airplanes is in use on a world wide basis, i.e. the effect of initial

deliveries to a small number of users in a given part of the world should not be

considered in this analysis but rather assume that the mature fleet will be used

throughout the world.

2, The operational environment is world wide when considering both airport

ambient and flight temperatures, as defined on the first figure below
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

14

3 The properties of certified fuels (as defined in the AFM) should be based on the

distributions defined on second figure below,

In order to simplify the process, the airplane flight times may be reduced to three types, a

short flight and medium flight and a long flight.

A random selection process is used to define a set of “flights” from which the fleet average

exposure is determined.

The technique is described as follows:

Sets of values are created for each variable that define a given flight, such as fuel flash

point, ground ambient temperature, cruise ambient temperature, range, fuel load and

usage, etc. Each set will contain a large number of values ( typically several thousands)

such that the data in each set matches the distribution of the values expected in service.

Each data set is then “shuffled” to generate a random order. By selecting the nth value of

variables from each set a “random” flight is created. This is then used to compute the fuel

temperature and time of flammability for a single flight. This process is repeated several

thousand times and the individual flight flammability exposures are summed to develop a

fleet average flammability exposure. Computing time can be reduced considerably by

calculating a matrix of flight cases for a range of ambient and flight conditions and

interpolating for each random flight case being considered.

An example of the process is attached as appendix 1.

To satisfy the requirement of the FAR/JAR, the fleet average exposure for each tank

should be less than 7% of total operational time. If the 7% level cannot be achieved, the

applicant should consider alternative means to reduce flammability, or to mitigate the

effect of an ignition in the tank. These are discussed in Section 6 above.

Method II

This process may only be used on airplanes which have approved fuels with a flash point

of 100oF or above.

In flight, the fuel temperature in a typical wing fuel tank responds to a step change in TAT

( total air temperature) with an exponential decay response to eventually reach the new

TAT, assuming the flight continues for a long enough time. (The most common analogy

to this process is the decay of capacitor voltage during discharge across a fixed

resistance). Analysis of such tanks on a variety of certified airplanes, using Jet A type

fuels, has shown that tanks with a rapid enough response to changes in total air

temperature will result in a satisfactory flammability exposure as required by 25.981(b),

provided there is no large heat input on the ground to increase fuel temperatures in the

tank prior to flight or significant heat input from airplane systems in flight.

This method of demonstrating an acceptable flammability exposure is therefore to show by

analysis or test the thermal response of each tank on the ground and in flight. The

response of the fuel temperature to a change in TAT may be expressed as an exponential

response as follows:
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

15

Delta FTt = Delta TAT x (1-e-t/T )

Where Delta FTt is the change in fuel temperature at time t, and Delta TAT is a step

change in TAT, and T is the time constant for the fuel temperature in the subject tank.

A tank will meet the intent of the flammability exposure requirement of 25.981(b) if the

tank satisfies the following;

1, The response of the fuel temperature is such that the time constant T is less

than 120 minutes with a full tank,

( Note: at the time of submittal of this report the value of the time constant had

not been finalized and needs to be verified)

2, The time constant, T, decreases as fuel is used and is not subject to additional

heat load at lower fuel quantities,

3, The fuel temperature does not increase on the ground from heat input from

other airplane systems during normal operation, by more that 5oF per hour with

any amount of fuel in the tank from unusable to full.

Fleetwide Distribution of Ambient Temperatures

Ground (Sea Level) and Cruise (Altitude of 35,000 ft.)

0%

25%

50%

75%

100%

-80 -60 -40 -20 0 20 40 60 80 100 120

Ambient Temperature (F)

Cummulative Probability

Ground Temp (F)

Cruise Temp (F)
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

16

Jet A Fuel, Worldwide Distribution

Fleetwide Distribution of Fuel Flash Point

0%

25%

50%

75%

100%

100 105 110 115 120 125

Fuel Flash Point Temperature (F)

Cummulative Probability
14th July, 1998

Task Group 8, Standards and Proposed Regulatory Action

17

Attachment to Task Group 8 Report

Common Airplane and Mission Data

and

Performance Trades and Cost Trades
Std missions exl7A.xls

Fleetwide Distribution of Ambient Temperatures

Ground & Cruise (Altitude of 35,000 ft.)

0

0.2

0.4

0.6

0.8

1

1.2

-9

0

-8

0

-7

0

-6

0

-5

0

-4

0

-3

0

-2

0

-1

0

0 10203040506070809010

0

11

0

12

0

13

0

Ambient Temperature (F)

Cummulative Probability

Ground

Cruise (35K)

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Small Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Small Airplane

Short Range Mission

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

0 1 2 3

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Small Airplane

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Small Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3 4

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Small Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

0 1 2 3 4

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Small Airplane

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Small Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temperature (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Small Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Small Airplane

Long Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temperature (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Medium Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Medium Airplane

Short Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Medium Airplane

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Medium Airplane

Long Range Mission

0

20,000

40,000

60,000

80,000

100,000

120,000

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Long Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Large Airplane

Short Range Mission

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Short Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Large Airplane

Medium Range Mission

0

50,000

100,000

150,000

200,000

250,000

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Medium Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10111213141516

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Large Airplane

Long Range Mission

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

0 1 2 3 4 5 6 7 8 9 10111213141516

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Long Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10111213141516

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Regional Turbofan

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2

Time (hr)

Altitude (ft)

Pressure Alt

Regional Turbofan

-100

-50

0

50

100

150

0 1 2

Time (hr)

Ambient Temp (F)

-8

37

57

72

90

100

111

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Regional Turbofan

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

0 1 2

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Regional Turbofan

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Regional Turboprop

0

5,000

10,000

15,000

20,000

25,000

0 1 2

Time (hr)

Altitude (ft)

Pressure Alt

Regional Turboprop

-40

-20

0

20

40

60

80

100

120

0 1 2

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Regional Turboprop

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

0 1 2

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Regional Turboprop

-40

-20

0

20

40

60

80

100

120

140

0 1 2

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Bizjet

Short Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Bizjet

Short Range Mission

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

0 1 2 3 4

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot

99.9%

Bizjet

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7 8

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Very Hot 99%

7/8/98 Bookexl4 Attachement to TG 8 Report
Std missions exl7A.xls

Bizjet

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

0 1 2 3 4 5 6 7 8

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

7/8/98 Bookexl4 Attachement to TG 8 Report
Standards-generic

Model Large Medium Small Regional Regional Bizjet

T/fan T/prop

General

 Fleet size 2,000 1,400 8,600 1,000 2,000 8,600

 MTOGW 800,000 330,000 160,000 78,000 40,000 23,000

 MLW 600,000 270,000 130,000 69,000 38,000 20,000

Fuel Volume:

 Total 54,000 24,000 5,000 3200 1400 1200

 Center 25,000 10,000 3,000 800 0 0

 Wing 26,000 12,000 2,000 2400 1400 800

 Tail 3,000 2,000 0 0

 Body (optional) (optional) (optional) 0 0 400

Tank Configurations

 % fleet with Center Tanks 92 97 97 6

 % of Center Tanks with Heat Input 64 78 72 0

 % fleet with Tail Tanks 36 25 0 0

 % fleet with Body Tanks 2 0 8 54

Tank Pressure

 Positive +1.5 +1.5 +1.5 2 2 +1.5

 Negative -0.5 -0.5 -0.5 -1 -1 -0.5

Bleed flow available after ECS

Bleed pressure avail after ECS

Bleed temperature avail after ECS

Precooler flow avail after ECS

Precooler max outlet temperature at 

max flow

Payload (lbs) 100,000 55,000 40,000 35,000 22,000 1,200

passengers 400 250 150 75 50 6

Short mission

 Range (nm) 2,000 1,000 500 1000

 Ground Time (hr) 2.00 1.50 1.25

 Block Time (hr) 4.6 2.3 1.6

 # of flights per day 2,914 3,682 35,548

Medium Mission

 Range (nm) 4,000 2,000 1,000 450 250 3000

 Ground Time (hr) 2.00 1.50 1.25 0.33 0.33

 Block Time (hr) 8.6 4.6 2.8 1.4 1.1

 # of flights per day 1,141 919 10,053 10,000 20,000

Long mission

 Range (nm) 6,000 4,000 2,000 6500

 Ground Time (hr) 2.00 1.50 1.25

 Block Time (hr) 12.7 8.9 5.1

 # of flights per day 544 541 2,566

Distribution

 % short missions 63% 72% 74% 54%

 %medium missions 25% 18% 21% 100% 100% 27%

 %long missions 12% 11% 5% 19%

Operating environment

 Max. Cruise Alt. 43,000 43,000 37,000 35,000 25,000 41,000

 Ground temp max 130 Deg F 130 Deg F 130 Deg F 122 Deg F 122 Deg F 122 Deg F

 Ground temp min -65 Deg F -65 Deg F -65 Deg F -40 Deg F -40 Deg F -40 Deg F

 Distribution of Ground Temp -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F

 Distribution of Cruise Temp -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F

 Distribtuion of Flash Point 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F

 Vmo 365 360 340 320 250 360

 Mmo 0.92 0.85 0.82 .0.80 0.5 0.83

 M cruise 0.85 0.80 0.77 0.75 290T/220E 0.8

 Climb rate (Max, Sea Level) 5,000 5,000 4,500 3000 2000

 Descent rate (Normal) 2,000 1,500 2,000 2000 2000

 Descent rate (Max) 3,500 4,000 3,000

Airplane Standards (3).xls Page 1 7/8/98
Standards-modeled

Model Large Medium Small Regional Regional Bizjet

T/fan T/prop

General

 Fleet size 2,000 1,400 8,600 1,000 2,000 787

 MTOGW 800,000 330,000 160,000 78,000 40,000 90,500

 MLW 600,000 270,000 130,000 69,000 38,000 75,300

Fuel Volume: 0 0 0 0 0

 Total 54,000 24,000 5,000 3,200 1,400 6,150

 Center 25,000 10,000 3,000 800 0 0

 Wing 26,000 12,000 2,000 2,400 1,400 6,150

 Tail 3,000 2,000 0 0 0 0

 Body (optional) (optional) (optional) 0 0 0

Tank Configurations

 % fleet with Center Tanks 92 97 97 0

 % of Center Tanks with Heat Input 64 78 72 0

 % fleet with Tail Tanks 36 25 0 0

 % fleet with Body Tanks 2 0 8 0

Tank Pressure

 Positive +1.5 +1.5 +1.5 2 2 2

 Negative -0.5 -0.5 -0.5 -1 -1 -0.5

Bleed flow available after ECS -

Bleed pressure avail after ECS -

Bleed temperature avail after ECS -

Precooler flow avail after ECS -

Precooler max outlet temperature at 

max flow -

Payload (lbs) 100,000 55,000 40,000 35,000 22,000 6,500

passengers 400 250 150 75 50 6 to19

Short mission

 Range (nm) 2,000 1,000 500 1,000

 Ground Time (hr) 2.0 1.5 1.3 1

 Block Time (hr) 4.6 2.3 1.6 3

 # of flights per day 2,914 3,682 35,548 1

Medium Mission

 Range (nm) 4,000 2,000 1,000 400 250 3,000

 Ground Time (hr) 2.0 1.5 1.3 0.5 0.3 1

 Block Time (hr) 8.6 4.6 2.8 1.0 1.1 7

 # of flights per day 1,141 919 10,053 20,000 1

Long mission

 Range (nm) 6,000 4,000 2,000 800 6,000

 Ground Time (hr) 2.0 1.5 1.3 0.5 1

 Block Time (hr) 12.7 8.9 5.1 2.0 15

 # of flights per day 544 541 2,566 1

Distribution Now/2002

 % short missions 63.4% 71.6% 73.8% 0.0% 0.0% 82.9/74.4

 %medium missions 24.8% 17.9% 20.9% 100.0% 100.0% 16.5/20.2

 %long missions 11.8% 10.5% 5.3% 0.0% 0.0% 0.6/5.4

Operating environment

 Max. Cruise Alt. 43,000 43,000 37,000 35,000 25,000 51,000

 Ground temp max 130 Deg F 130 Deg F 130 Deg F 122 Deg F 122 Deg F 133°F

 Ground temp min -65 Deg F -65 Deg F -65 Deg F -40 Deg F -40 Deg F -65°F

 Distribution of Ground Temp -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F -40 to 122 F

 Distribution of Cruise Temp -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F -87 to -22 F

 Distribtuion of Flash Point 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F 100 to 150 F

 Vmo 365 360 340 320 250 340kTAS

 Mmo 1 1 1 .0.80 1 1

 M cruise 1 1 1 1 290T/220E 1

 Climb rate (Max, Sea Level) 5,000 5,000 4,500 3,000 2,000 6700/3600 @ 51,000# / 90,500

 Descent rate (Normal) 2,000 1,500 2,000 2,000 2,000 2,000

 Descent rate (Max) 3,500 4,000 3,000 0 0 20,000

Airplane Standards (3).xls Page 1 7/8/98
Cost Estimator

NOTES:

This page attempts to estimate the performance related costs to the airlines of increased airplane weight

and / or reduced fuel volume. These costs include increased fuel burn and payload reduction.

They do not include airline maintenance costs, manufacturers cost or airplane price changes.

The assumptions used in this cost estimate are shown on the top of the Peformance & Cost Trades worksheet

Data is not ready for the Regional Turboprop.

Input airplane weight increase and / or fuel volume decrease. The airline cost will update automatically.

Model Large Medium Small Regional Regional Bizjet

T/fan T/prop

Input :

 Airplane weight increase (lb) 1,000 1,000 1,000 1,000 1,000 1,000

 Fuel volume decrease (gal) 100 100 100 100 100 100

Airline cost increase (total fleet per year)

 short mission $16,050,712 $8,691,207 $63,252,006 $0 $0 $2,041,454

 medium mission $8,212,986 $2,932,221 $21,346,537 $19,765,404 $0 $1,895,636

 long mission (takeoff weight limited) $153,400,000 $86,450,000 $224,318,714 $0 $0 $592,000,794

 long mission (fuel volume limited) $306,800,000 $181,545,000 $717,819,886 $0 $0 $1,340,923,194

Output:

 Total Airline Cost Increase (entire fleet per year) $484,463,698 $279,618,429 $1,026,737,144 $19,765,404 $0 $1,936,861,077

 Total Airline Cost Increase (per airplane per year) $242,232 $199,727 $119,388 $19,765 $0 $225,216

Airplane Standards (3).xls, Cost Estimator 7/8/98
Performance & Cost Trades

Assumptions:

Fuel Density = 6.70 Lbs/Gal

Model Large Medium Small Regional Regional Bizjet

T/fan T/prop

Assumed Fuel Price ($ / gallon) $0.70 $0.70 $0.70 $0.70 $0.70 $1.50

Trades when not limited by takeoff weight or fuel volume (short / medium missions)

 ( i.e. add extra fuel to carry extra aircraft weight over a fixed range with a fixed payload) Bizjet data

based on generic

Airline Cost per Airplane bizjet, not the

modelled bizjet

Short mission

 Range (nm) 2,000 1,000 500 400

 # of flights per year per airplane 795 1,300 2,120 149

 % Block fuel / 1000 lbs OEW 0.17% 0.30% 0.63% 0.34%

 Block Fuel (lb) 89,647 21,279 7,142 2100

 Lbs block fuel / 1000 lbs OEW / Flight 152 64 45 7

 Lbs block fuel / 1000 lbs OEW / Year 121,158 82,988 95,389 1,060

 $ / 1000 lbs OEW / Year 12,658 8,670 9,966 237

Medium mission

 Range (nm) 4,000 2,000 1,000 450 250 1000

 # of flights per year per airplane 475 795 1,300 3650 3650 74

 % Block fuel / 1000 lbs OEW 0.18% 0.34% 0.68% 1.30% 0% 0.34%

 Block Fuel (lb) 185,366 41,433 12,859 3987 1534 3900

 Lbs block fuel / 1000 lbs OEW / Flight 334 141 87 52 0 13

 Lbs block fuel / 1000 lbs OEW / Year 158,488 111,993 113,674 189,183 0 985

 $ / 1000 lbs OEW / Year 16,558 11,701 11,876 19,765 0 220

Long mission

 Range (nm) 6,000 4,000 2,000 2000

 # of flights per year per airplane 350 475 795 52

 % Block fuel / 1000 lbs OEW 0.19% 0.35% 0.81% 0.34%

 Block Fuel (lb) 298,697 86,603 25,174 6400

 Lbs block fuel / 1000 lbs OEW / Flight 568 303 204 22

 Lbs block fuel / 1000 lbs OEW / Year 198,634 143,977 162,108 1,137

 $ / 1000 lbs OEW / Year 20,753 15,042 16,937 255

Trades when limited by takeoff weight (50% of long missions)

 ( i.e. reduce payload by amount of increased aircraft weight to maintain fixed range)

Range Trade -25 -45 -90 -160 -300

(N. Mi. / 1000 lbs OEW)

Payload Trade 1,000 1,000 1,000 1000 1000 1000

(Reduced payload / 1000 lbs OEW)

Airline Cost

 Reduced Payload (lb) 1,000 1,000 1,000 1000 1000 1000

 Passengers left behind (210 lbs/pass) 4.8 4.8 4.8 4.8 4.8 4.8

 Range (nm) 6,000 4,000 2,000 2000

 $ per Revenue Seat Mile $0.130 $0.130 $0.130 $0.135 $0.135 $0.138

 # of flights per year per airplane 350 475 795 52

 $ / 1000 lbs OEW / airplane / year 1,300,000 1,176,190 984,286 0 0 68,837

Cost assumes the airplane is takeoff weight

limited on every flight.

Trades when limited by fuel volume (50% of long missions)

 ( i.e. reduce payload by amount of increased aircraft weight and OEW/gallon trade)

Range Trade -12 -20 -25

(N. Mi. / 1000 lbs OEW)

Airline Cost

 Increased OEW effect (per 1000 lbs)

 $ / 1000 lbs OEW / airplane / year 1,300,000 1,176,190 984,286 0 0 68,837

 (Same as takeoff weight limited case)

 Decreased fuel volume effect (per 100 gal)

 Payload reduction per gal of fuel 10 11 22 0 0 43

 Reduced Payload (lb) 1,000 1,100 2,200 0 0

 Passengers left behind (210 lbs/pass) 4.8 5.2 10.5 0.0 0.0

 Range (nm) 6,000 4,000 2,000

 $ per Revenue Seat Mile $0.130 $0.130 $0.130 $0.135 $0.135

 # of flights per year per airplane 350 475 795

 $ / 100 gal / airplane / year 1,300,000 1,293,810 2,165,429 0 0 87,084

Cost assumes the flight is fuel volume

limited on every flight.

Airplane Standards (3).xls, Performance & Cost Trades Page 1 7/8/98
Temperatures

Condition of Day Cummulative Probability Ground Cruise (35K) Ground Cruise (35K) NOTE: This temperature data is built into the profiles 

( Deg C) ( Deg C) ( Deg F) ( Deg F)

Min 0.01% -40 -66 -40 -87

Extremely Cold 0.1% -30 -64 -22 -83 Very Cold 1%Cool 25% Average 50% Warm 75%Hot 95%Very Hot 99%Extremely Hot 99.9%

Very Cold 1% -22 -61 -8 -78 Ground Ambient (F) -8 37 57 72 90 100 111

Cold 25% 3 -51 37 -60 Enroute Ambient (35k, Deg F) -78 -60 -53 -45 -38 -33 -27

Average 50% 14 -47 57 -53 Enroute Isa +(F) -12 6 13 20 28 33 38

Warm 75% 22 -43 72 -45

Hot 95% 32 -39 90 -38 Altitude Ambient Temperature - Degrees F

Very Hot 99% 38 -36 100 -33 0 -8 37 57 72 90 100 111

Extremely Hot 99.9% 44 -33 111 -27 1000 -8 35 54 68 86 96 107

Max 99.99% 50 -30 122 -22 2000 -9 33 52 65 82 92 103

3000 -10 31 49 62 78 88 98

BOLD Indicates cases to run in thermal model 4000 -11 29 46 59 75 84 94

5000 -12 26 43 56 71 80 90

6000 -13 24 40 53 67 76 86

7000 -13 22 37 49 64 73 81

8000 -14 20 35 46 60 69 77

9000 -15 18 32 43 56 65 73

10000 -16 16 29 40 52 61 69

11000 -17 13 26 37 49 57 64

12000 -18 11 23 33 45 53 60

13000 -18 9 21 30 41 49 56

14000 -19 7 18 27 38 45 52

15000 -20 5 15 24 34 41 47

16000 -21 2 12 21 30 37 43

17000 -22 0 9 18 26 33 39

18000 -23 -2 7 14 23 29 35

19000 -23 -4 4 11 19 25 30

20000 -24 -6 1 8 15 21 26

21000 -28 -10 -3 5 12 17 23

22000 -31 -13 -6 1 8 14 19

23000 -35 -17 -10 -3 5 10 15

24000 -39 -21 -13 -6 1 6 12

25000 -42 -24 -17 -10 -3 3 8

26000 -46 -28 -21 -13 -6 -1 5

27000 -49 -31 -24 -17 -10 -4 1

28000 -53 -35 -28 -20 -13 -8 -2

29000 -56 -38 -31 -24 -17 -11 -6

30000 -60 -42 -35 -28 -20 -15 -10

31000 -64 -46 -38 -31 -24 -19 -13

32000 -67 -49 -42 -35 -27 -22 -17

33000 -71 -53 -45 -38 -31 -26 -20

34000 -74 -56 -49 -42 -35 -29 -24

35000 -78 -60 -53 -45 -38 -33 -27

36000 -81 -63 -56 -49 -42 -36 -31

36089 -82 -64 -56 -49 -42 -37 -31

37000 -82 -64 -56 -49 -42 -37 -31

38000 -82 -64 -56 -49 -42 -37 -31

39000 -82 -64 -56 -49 -42 -37 -31

40000 -82 -64 -56 -49 -42 -37 -31

41000 -82 -64 -56 -49 -42 -37 -31

42000 -82 -64 -56 -49 -42 -37 -31

43000 -82 -64 -56 -49 -42 -37 -31

44000 -82 -64 -56 -49 -42 -37 -31

45000 -82 -64 -56 -49 -42 -37 -31

46000 -82 -64 -56 -49 -42 -37 -31

47000 -82 -64 -56 -49 -42 -37 -31

48000 -82 -64 -56 -49 -42 -37 -31

49000 -82 -64 -56 -49 -42 -37 -31

50000 -82 -64 -56 -49 -42 -37 -31

51000 -82 -64 -56 -49 -42 -37 -31

52000 -82 -64 -56 -49 -42 -37 -31

53000 -82 -64 -56 -49 -42 -37 -31

54000 -82 -64 -56 -49 -42 -37 -31

55000 -82 -64 -56 -49 -42 -37 -31

56000 -82 -64 -56 -49 -42 -37 -31

57000 -82 -64 -56 -49 -42 -37 -31

58000 -82 -64 -56 -49 -42 -37 -31

59000 -82 -64 -56 -49 -42 -37 -31

60000 -82 -64 -56 -49 -42 -37 -31

Fleetwide Distribution of Ambient Temperatures

Ground & Cruise (Altitude of 35,000 ft.)

-20%

0%

20%

40%

60%

80%

100%

120%

-9

0

-8

0

-7

0

-6

0

-5

0

-4

0

-3

0

-2

0

-1

0

0 10 20 30 40 50 60 70 80 90 10

0

11

0

12

0

13

0

Ambient Temperature (F)

Cummulative Probability

Ground

Cruise (35K)

Airplane Standards (3).xls, Temperatures 7/8/98
Small Commercial Transport

Short Range Mission

Ground Time (takeoff) = 45.000 minutes Main 1 Fuel Volume = 1000 gal Tank Volume = 1020 Main 1/2 =

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 1000 gal Tank Volume = 1020

CWT Fuel Volume = 3,000 gal Tank Volume = 3060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

Main 

Tank 2 

Fuel 

Remainin

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 110874 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 13173 6587 6587 0 0

36.0 0.6 0 0.0 0.000 110874 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 13173 6587 6587 0 0

45.0 0.8 0 0.0 0.000 110622 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 16119 269 12921 6461 6461 0 0

46.6 0.8 1500 3.5 0.388 110211 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 16119 269 12510 6255 6255 0 4525 14.3

46.7 0.8 2000 4.0 0.391 110181 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 15950 266 12480 6240 6240 0 4482 14.1

47.1 0.8 4000 5.9 0.406 110063 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 15290 255 12362 6181 6181 0 4309 13.4

47.6 0.8 6000 8.0 0.420 109945 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 14649 244 12244 6122 6122 0 4135 12.8

48.1 0.8 8000 10.3 0.436 109826 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 14004 233 12125 6063 6063 0 3950 12.2

48.6 0.8 10000 12.7 0.452 109708 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 12007 6004 6004 0 3753 11.6

48.6 0.8 10000 12.7 0.452 109708 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 12007 6004 6004 0 500 5.2

48.9 0.8 10126 14.0 0.507 109651 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13555 226 11950 5975 5975 0 500 4.0

48.9 0.8 10126 14.0 0.507 109651 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13553 226 11950 5975 5975 0 3783 9.8

49.4 0.8 12000 16.8 0.525 109539 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 12980 216 11838 5919 5919 0 3577 9.2

50.0 0.8 14000 20.0 0.544 109417 -19 7 18 27 38 45 52 7 34 46 56 67 74 82 12377 206 11716 5858 5858 0 3355 8.7

50.6 0.8 16000 23.6 0.565 109293 -21 2 12 21 30 37 43 7 32 42 51 61 68 75 11750 196 11592 5796 5796 0 3125 8.1

51.2 0.9 18000 27.5 0.587 109166 -23 -2 7 14 23 29 35 7 30 39 47 56 62 69 11125 185 11465 5733 5733 0 2889 7.6

52.0 0.9 20000 32.0 0.610 109036 -24 -6 1 8 15 21 26 8 27 35 43 51 56 62 10562 176 11335 5668 5668 0 2658 7.1

52.7 0.9 22000 36.9 0.634 108900 -31 -13 -6 1 8 14 19 3 22 30 38 46 52 57 10082 168 11199 5600 5600 0 2438 6.6

53.6 0.9 24000 42.6 0.659 108759 -39 -21 -13 -6 1 6 12 -2 18 25 33 41 47 53 9600 160 11058 5529 5529 0 2217 6.2

54.6 0.9 26000 49.0 0.685 108611 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37 42 48 9125 152 10910 5455 5455 0 1986 5.7

55.6 0.9 28000 56.5 0.713 108451 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32 38 44 8679 145 10750 5375 5375 0 1752 5.2

56.8 0.9 29855 64.6 0.740 108291 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 10590 5295 5295 0 1531 4.8

56.8 0.9 29855 64.6 0.740 108291 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 10590 5295 5295 0 2091 5.5

56.8 0.9 30000 65.1 0.740 108282 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28 34 40 8248 137 10581 5291 5291 0 2072 5.5

57.9 1.0 32000 72.6 0.740 108144 -67 -49 -42 -35 -27 -22 -17 -24 -4 4 12 20 26 32 7682 128 10443 5222 5222 0 1806 5.5

59.1 1.0 34000 81.3 0.740 107995 -74 -56 -49 -42 -35 -29 -24 -32 -12 -4 4 12 18 24 7134 119 10294 5147 5147 0 1521 5.5

59.8 1.0 35000 86.2 0.740 107914 -78 -60 -53 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 6868 114 10213 5107 5107 0 1373 5.5

71.1 1.2 35000 167.5 0.745 107029 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4665 78 9328 4664 4664 0 0 3.5

84.8 1.4 35000 265.2 0.745 105970 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4633 77 8269 4135 4135 0 0 3.5

98.6 1.6 35000 363.7 0.745 104912 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4602 77 7211 3606 3606 0 0 3.5

103.6 1.7 35000 400.1 0.745 104523 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4590 77 6822 3411 3411 0 0 3.5

103.7 1.7 34923 400.3 0.740 104522 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 6821 3411 3411 0 3101 -0.6

103.7 1.7 34923 400.3 0.740 104522 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 6821 3411 3411 0 2274 0.5

104.1 1.7 34000 403.1 0.726 104517 -74 -56 -49 -42 -35 -29 -24 -34 -14 -6 2 10 16 22 760 13 6816 3408 3408 0 2239 0.5

105.0 1.7 32000 409.4 0.696 104506 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 775 13 6805 3403 3403 0 2195 0.6

105.9 1.8 30000 415.5 0.668 104493 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 820 14 6792 3396 3396 0 2143 0.7

106.8 1.8 28000 421.6 0.641 104480 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 877 15 6779 3390 3390 0 2091 0.7

107.8 1.8 26000 427.6 0.616 104465 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 933 16 6764 3382 3382 0 2039 0.7

108.8 1.8 24000 433.6 0.592 104449 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 996 17 6748 3374 3374 0 1989 0.8

109.8 1.8 22000 439.6 0.569 104432 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 1062 18 6731 3366 3366 0 1941 0.8

110.9 1.8 20000 445.5 0.547 104413 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 1132 19 6712 3356 3356 0 1894 0.7

111.9 1.9 18000 451.4 0.526 104392 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 1206 20 6691 3346 3346 0 1843 0.8

113.0 1.9 16000 457.3 0.506 104369 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 1283 21 6668 3334 3334 0 1792 0.8

114.2 1.9 14000 463.2 0.487 104344 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 1365 23 6643 3322 3322 0 1741 0.8

115.3 1.9 12000 469.0 0.469 104317 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 1450 24 6616 3308 3308 0 1691 0.7

116.5 1.9 10000 474.9 0.452 104287 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 1540 26 6586 3293 3293 0 1640 0.7

117.8 2.0 8000 480.7 0.436 104254 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 1633 27 6553 3277 3277 0 1591 0.7

119.1 2.0 6000 486.6 0.420 104218 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 1732 29 6517 3259 3259 0 1541 0.8

120.4 2.0 4000 492.5 0.406 104179 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 1853 31 6478 3239 3239 0 1483 0.8

121.8 2.0 2000 498.5 0.391 104134 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 2004 33 6433 3217 3217 0 1421 0.8

122.1 2.0 1500 500.0 0.388 104122 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 2045 34 6421 3211 3211 0 1405 0.8

127.1 2.1 0 500.0 0.000 103872 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 6171 3086 3086 0 0

132.1 2.2 0 500.0 0.000 103732 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6031 3016 3016 0 0

157.1 2.6 0 500.0 0.000 103732 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6031 3016 3016 0 0

Airplane Standards (3).xls, Profile-small-short 7/8/98
Charts-small-short

Small Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Short Range Mission

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

0 1 2 3

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Small Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Small Airplane

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-small-short 7/8/98
Small Commercial Transport

Medium Range Mission

Ground Time (takeoff) = 45.000 minutes Main 1 Fuel Volume = 1000 gal Tank Volume = 1020

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 1000 gal Tank Volume = 1020

CWT Fuel Volume = 3,000 gal Tank Volume = 3060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

Main 

Tank 2 

Fuel 

Remainin

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 

99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 116876 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 19176 6700 6700 5776 0

36.0 0.6 0 0.0 0.000 116876 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 19176 6700 6700 5776 0

45.0 0.8 0 0.0 0.000 116624 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 16119 269 18924 6700 6700 5524 0

46.6 0.8 1500 3.6 0.388 116192 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 16119 269 18492 6700 6700 5092 4236 13.9

46.7 0.8 2000 4.1 0.391 116160 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 15950 266 18460 6700 6700 5060 4195 13.8

47.2 0.8 4000 6.2 0.406 116033 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 15290 255 18333 6700 6700 4933 4029 13.1

47.7 0.8 6000 8.4 0.420 115907 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 14649 244 18207 6700 6700 4807 3863 12.5

48.2 0.8 8000 10.9 0.436 115780 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 14004 233 18080 6700 6700 4680 3686 11.9

48.8 0.8 10000 13.5 0.452 115653 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 17953 6700 6700 4553 3498 11.3

48.8 0.8 10000 13.5 0.452 115653 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 17953 6700 6700 4553 500 5.5

49.0 0.8 10137 14.9 0.507 115592 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13551 226 17892 6700 6700 4492 500 4.2

49.0 0.8 10137 14.9 0.507 115592 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13550 226 17892 6700 6700 4492 3536 9.5

49.6 0.8 12000 17.8 0.525 115472 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 12980 216 17772 6700 6700 4372 3341 9.0

50.2 0.8 14000 21.3 0.544 115342 -19 7 18 27 38 45 52 7 34 46 56 67 74 82 12377 206 17642 6700 6700 4242 3129 8.5

50.9 0.8 16000 25.1 0.565 115208 -21 2 12 21 30 37 43 7 32 42 51 61 68 75 11750 196 17508 6700 6700 4108 2910 8.0

51.6 0.9 18000 29.4 0.587 115072 -23 -2 7 14 23 29 35 7 30 39 47 56 62 69 11125 185 17372 6700 6700 3972 2685 7.5

52.4 0.9 20000 34.2 0.610 114932 -24 -6 1 8 15 21 26 8 27 35 43 51 56 62 10562 176 17232 6700 6700 3832 2463 7.0

53.2 0.9 22000 39.5 0.634 114786 -31 -13 -6 1 8 14 19 3 22 30 38 46 52 57 10082 168 17086 6700 6700 3686 2253 6.5

54.1 0.9 24000 45.6 0.659 114633 -39 -21 -13 -6 1 6 12 -2 18 25 33 41 47 53 9600 160 16933 6700 6700 3533 2042 6.1

55.2 0.9 26000 52.6 0.685 114471 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37 42 48 9125 152 16771 6700 6700 3371 1822 5.7

56.3 0.9 28000 60.8 0.713 114297 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32 38 44 8679 145 16597 6700 6700 3197 1598 5.2

57.6 1.0 29855 69.8 0.740 114120 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 16420 6700 6700 3020 1383 4.8

57.6 1.0 29855 69.8 0.740 114120 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 16420 6700 6700 3020 1889 5.4

57.7 1.0 30000 70.3 0.740 114110 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28 34 40 8248 137 16410 6700 6700 3010 1871 5.4

58.8 1.0 32000 78.7 0.740 113956 -67 -49 -42 -35 -27 -22 -17 -24 -4 4 12 20 26 32 7682 128 16256 6700 6700 2856 1605 5.4

60.2 1.0 34000 88.6 0.740 113787 -74 -56 -49 -42 -35 -29 -24 -32 -12 -4 4 12 18 24 7134 119 16087 6700 6700 2687 1322 5.4

61.0 1.0 35000 94.3 0.740 113693 -78 -60 -53 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 6868 114 15993 6700 6700 2593 1173 5.4

64.9 1.1 35000 121.9 0.745 113379 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4873 81 15679 6700 6700 2279 0 3.8

78.0 1.3 35000 215.5 0.745 112321 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4837 81 14621 6700 6700 1221 0 3.8

91.1 1.5 35000 309.8 0.745 111263 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4801 80 13563 6700 6700 163 0 3.7

104.4 1.7 35000 404.9 0.745 110204 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4766 79 12504 6252 6252 0 0 3.7

117.8 2.0 35000 500.6 0.745 109146 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4732 79 11446 5723 5723 0 0 3.6

131.3 2.2 35000 597.0 0.745 108087 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4698 78 10387 5194 5194 0 0 3.6

144.8 2.4 35000 694.1 0.745 107029 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4665 78 9329 4665 4665 0 0 3.5

158.5 2.6 35000 791.8 0.745 105970 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4633 77 8270 4135 4135 0 0 3.5

172.2 2.9 35000 890.3 0.745 104912 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4602 77 7212 3606 3606 0 0 3.5

173.6 2.9 35000 900.0 0.745 104808 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4599 77 7108 3554 3554 0 0 3.5

173.6 2.9 34923 900.2 0.740 104808 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 7108 3554 3554 0 3099 -0.6

173.6 2.9 34923 900.2 0.740 104808 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 7108 3554 3554 0 2272 0.5

174.0 2.9 34000 903.1 0.726 104802 -74 -56 -49 -42 -35 -29 -24 -34 -14 -6 2 10 16 22 760 13 7102 3551 3551 0 2237 0.6

174.9 2.9 32000 909.3 0.696 104791 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 775 13 7091 3546 3546 0 2193 0.6

175.8 2.9 30000 915.4 0.668 104779 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 820 14 7079 3540 3540 0 2142 0.7

176.8 2.9 28000 921.5 0.641 104765 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 877 15 7065 3533 3533 0 2089 0.7

177.8 3.0 26000 927.6 0.616 104751 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 933 16 7051 3526 3526 0 2037 0.8

178.8 3.0 24000 933.6 0.592 104735 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 996 17 7035 3518 3518 0 1987 0.8

179.8 3.0 22000 939.6 0.569 104717 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 1062 18 7017 3509 3509 0 1940 0.8

180.8 3.0 20000 945.5 0.547 104698 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 1132 19 6998 3499 3499 0 1892 0.8

181.9 3.0 18000 951.4 0.526 104677 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 1206 20 6977 3489 3489 0 1841 0.8

183.0 3.0 16000 957.3 0.506 104654 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 1283 21 6954 3477 3477 0 1790 0.8

184.1 3.1 14000 963.1 0.487 104629 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 1365 23 6929 3465 3465 0 1740 0.8

185.3 3.1 12000 969.0 0.469 104602 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 1450 24 6902 3451 3451 0 1690 0.8

186.5 3.1 10000 974.8 0.452 104572 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 1540 26 6872 3436 3436 0 1639 0.8

187.7 3.1 8000 980.7 0.436 104539 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 1633 27 6839 3420 3420 0 1590 0.8

189.0 3.2 6000 986.6 0.420 104503 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 1732 29 6803 3402 3402 0 1539 0.8

190.3 3.2 4000 992.5 0.406 104464 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 1853 31 6764 3382 3382 0 1482 0.8

191.7 3.2 2000 998.5 0.391 104419 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 2004 33 6719 3360 3360 0 1420 0.8

192.1 3.2 1500 1000.0 0.388 104407 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 2045 34 6707 3354 3354 0 1404 0.9

197.1 3.3 0 1000.0 0.000 104157 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 6457 3229 3229 0 0

202.1 3.4 0 1000.0 0.000 104017 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6317 3159 3159 0 0

227.1 3.8 0 1000.0 0.000 104017 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6317 3159 3159 0 0

Airplane Standards (3).xls, Profile-small-medium 7/8/98
Charts-small-medium

Small Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3 4

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Medium Range Mission

Time (hr)

Small Airplane

Medium Range Mission

Time (hr)

Small Airplane

Medium Range Mission

Time (hr)

Airplane Standards (3).xls, Charts-small-medium 7/8/98
Small Commercial Transport

Long Range Mission

Ground Time (takeoff) = 45.000 minutes Main 1 Fuel Volume = 1000 gal Tank Volume = 1020 Main 1/2 =

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 1000 gal Tank Volume = 1020

CWT Fuel Volume = 3,000 gal Tank Volume = 3060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 129807 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 32108 6700 6700 18708 0

36.0 0.6 0 0.0 0.000 129807 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 32108 6700 6700 18708 0

45.0 0.8 0 0.0 0.000 129555 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 16119 269 31856 6700 6700 18456 0

46.7 0.8 1500 3.8 0.388 129082 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 16119 269 31383 6700 6700 17983 3694 13.3

46.8 0.8 2000 4.4 0.391 129045 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 15950 266 31346 6700 6700 17946 3657 13.2

47.4 0.8 4000 6.8 0.406 128900 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 15290 255 31201 6700 6700 17801 3505 12.6

48.0 0.8 6000 9.4 0.420 128754 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 14649 244 31055 6700 6700 17655 3353 12.1

48.6 0.8 8000 12.2 0.436 128608 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 14004 233 30909 6700 6700 17509 3190 11.5

49.2 0.8 10000 15.2 0.452 128461 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 30762 6700 6700 17362 3016 11.0

49.2 0.8 10000 15.2 0.452 128461 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 13350 223 30762 6700 6700 17362 500 6.1

49.6 0.8 10162 16.9 0.507 128389 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13544 226 30690 6700 6700 17290 500 4.7

49.6 0.8 10162 16.9 0.507 128389 -16 15 29 39 52 60 68 7 40 54 65 78 87 95 13542 226 30690 6700 6700 17290 3070 9.2

50.2 0.8 12000 20.2 0.525 128253 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 12980 216 30554 6700 6700 17154 2895 8.7

50.9 0.8 14000 24.2 0.544 128101 -19 7 18 27 38 45 52 7 34 46 56 67 74 82 12377 206 30402 6700 6700 17002 2701 8.3

51.7 0.9 16000 28.7 0.565 127947 -21 2 12 21 30 37 43 7 32 42 51 61 68 75 11750 196 30248 6700 6700 16848 2502 7.8

52.5 0.9 18000 33.7 0.587 127788 -23 -2 7 14 23 29 35 7 30 39 47 56 62 69 11125 185 30089 6700 6700 16689 2296 7.3

53.4 0.9 20000 39.3 0.610 127623 -24 -6 1 8 15 21 26 8 27 35 43 51 56 62 10562 176 29924 6700 6700 16524 2093 6.9

54.4 0.9 22000 45.6 0.634 127450 -31 -13 -6 1 8 14 19 3 22 30 38 46 52 57 10082 168 29751 6700 6700 16351 1901 6.5

55.5 0.9 24000 52.9 0.659 127268 -39 -21 -13 -6 1 6 12 -2 18 25 33 41 47 53 9600 160 29569 6700 6700 16169 1708 6.0

56.8 0.9 26000 61.3 0.685 127074 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37 42 48 9125 152 29375 6700 6700 15975 1507 5.6

58.2 1.0 28000 71.3 0.713 126862 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32 38 44 8679 145 29163 6700 6700 15763 1301 5.2

59.8 1.0 29855 82.5 0.740 126641 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 28942 6700 6700 15542 1094 4.8

59.8 1.0 29855 82.5 0.740 126641 -59 -41 -34 -27 -20 -14 -9 -16 4 12 20 28 34 40 8289 138 28942 6700 6700 15542 1495 5.3

59.9 1.0 30000 83.2 0.740 126628 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28 34 40 8248 137 28929 6700 6700 15529 1476 5.3

60.6 1.0 31000 88.3 0.740 126532 -64 -46 -38 -31 -24 -19 -13 -20 0 8 16 24 30 36 7965 133 28833 6700 6700 15433 1349 5.3

71.8 1.2 31000 170.0 0.745 125495 -64 -46 -38 -31 -24 -19 -13 -20 0 8 16 24 30 36 5531 92 27796 6700 6700 14396 0 3.4

72.6 1.2 32000 175.7 0.745 125394 -67 -49 -42 -35 -27 -22 -17 -24 -4 4 12 20 26 32 7705 128 27695 6700 6700 14295 1220 5.2

74.5 1.2 34000 189.4 0.745 125159 -74 -56 -49 -42 -35 -29 -24 -31 -11 -3 5 13 19 25 7156 119 27460 6700 6700 14060 924 5.2

75.7 1.3 35000 198.0 0.745 125019 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 6891 115 27320 6700 6700 13920 761 5.2

87.6 1.5 35000 283.1 0.745 123964 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5300 88 26265 6700 6700 12865 0 4.2

99.6 1.7 35000 369.3 0.745 122905 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5253 88 25206 6700 6700 11806 0 4.1

111.7 1.9 35000 456.3 0.745 121847 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5206 87 24148 6700 6700 10748 0 4.1

124.0 2.1 35000 544.0 0.745 120789 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5161 86 23090 6700 6700 9690 0 4.1

136.4 2.3 35000 632.5 0.745 119730 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5116 85 22031 6700 6700 8631 0 4.0

148.8 2.5 35000 721.8 0.745 118672 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5072 85 20973 6700 6700 7573 0 4.0

161.4 2.7 35000 811.8 0.745 117613 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 5030 84 19914 6700 6700 6514 0 4.0

174.1 2.9 35000 902.5 0.745 116555 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4989 83 18856 6700 6700 5456 0 3.9

186.9 3.1 35000 994.0 0.745 115496 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4950 82 17797 6700 6700 4397 0 3.9

199.7 3.3 35000 1086.2 0.745 114438 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4911 82 16739 6700 6700 3339 0 3.8

212.7 3.5 35000 1179.1 0.745 113379 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4873 81 15680 6700 6700 2280 0 3.8

225.8 3.8 35000 1272.7 0.745 112321 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4837 81 14622 6700 6700 1222 0 3.8

239.0 4.0 35000 1367.0 0.745 111263 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4801 80 13564 6700 6700 164 0 3.7

252.3 4.2 35000 1462.0 0.745 110204 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4766 79 12505 6253 6253 0 0 3.7

265.6 4.4 35000 1557.8 0.745 109146 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4732 79 11447 5724 5724 0 0 3.6

279.1 4.7 35000 1654.2 0.745 108087 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4698 78 10388 5194 5194 0 0 3.6

292.7 4.9 35000 1751.3 0.745 107029 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4665 78 9330 4665 4665 0 0 3.5

306.3 5.1 35000 1849.0 0.745 105970 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4633 77 8271 4136 4136 0 0 3.5

313.4 5.2 35000 1899.7 0.745 105424 -78 -60 -53 -45 -38 -33 -27 -35 -15 -7 1 9 15 21 4617 77 7725 3863 3863 0 0 3.5

313.4 5.2 34923 1899.9 0.740 105424 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 7725 3863 3863 0 3094 -0.6

313.4 5.2 34923 1899.9 0.740 105424 -78 -60 -52 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 760 13 7725 3863 3863 0 2269 0.5

313.8 5.2 34000 1902.8 0.726 105419 -74 -56 -49 -42 -35 -29 -24 -34 -14 -6 2 10 16 22 760 13 7720 3860 3860 0 2233 0.6

314.7 5.2 32000 1909.0 0.696 105407 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 775 13 7708 3854 3854 0 2189 0.7

315.7 5.3 30000 1915.2 0.668 105395 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 820 14 7696 3848 3848 0 2138 0.7

316.6 5.3 28000 1921.3 0.641 105381 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 877 15 7682 3841 3841 0 2085 0.8

317.6 5.3 26000 1927.3 0.616 105367 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 933 16 7668 3834 3834 0 2034 0.8

318.6 5.3 24000 1933.4 0.592 105351 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 996 17 7652 3826 3826 0 1983 0.8

319.6 5.3 22000 1939.3 0.569 105333 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 1062 18 7634 3817 3817 0 1936 0.8

320.6 5.3 20000 1945.3 0.547 105314 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 1132 19 7615 3808 3808 0 1888 0.8

321.7 5.4 18000 1951.2 0.526 105293 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 1206 20 7594 3797 3797 0 1838 0.8

322.8 5.4 16000 1957.1 0.506 105270 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 1283 21 7571 3786 3786 0 1787 0.8

324.0 5.4 14000 1963.0 0.487 105245 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 1365 23 7546 3773 3773 0 1737 0.8

325.1 5.4 12000 1968.8 0.469 105218 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 1450 24 7519 3760 3760 0 1686 0.8

326.3 5.4 10000 1974.7 0.452 105188 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 1540 26 7489 3745 3745 0 1636 0.8

327.6 5.5 8000 1980.6 0.436 105155 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 1633 27 7456 3728 3728 0 1587 0.8

328.9 5.5 6000 1986.5 0.420 105119 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 1732 29 7420 3710 3710 0 1537 0.8

330.2 5.5 4000 1992.4 0.406 105079 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 1853 31 7380 3690 3690 0 1480 0.8

331.6 5.5 2000 1998.4 0.391 105035 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 2004 33 7336 3668 3668 0 1417 0.9

331.9 5.5 1500 1999.9 0.388 105023 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 2045 34 7324 3662 3662 0 1402 0.9

336.9 5.6 0 1999.9 0.000 104773 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1680 28 7074 3537 3537 0 0

341.9 5.7 0 1999.9 0.000 104633 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6934 3467 3467 0 0

Airplane Standards (3).xls, Profile-small-long 7/8/98
Small Commercial Transport

Long Range Mission

366.9 6.1 0 1999.9 0.000 104633 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6934 3467 3467 0 0

Airplane Standards (3).xls, Profile-small-long 7/8/98
Charts-small-long

Small Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Small Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Small Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temperature (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Small Airplane

Long Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temperature (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-small-long 7/8/98
Charts-med-short

Medium Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Short Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-med-short 7/8/98
Charts-med-short

Medium Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Short Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-med-short 7/8/98
Medium Commercial Transport

Medium Range Mission

Ground Time (takeoff) = 60.000 minutes Main 1 Fuel Volume = 6,000 gal Tank Volume = 6,120 Threshold fuel in CWT to trigger

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 6,000 gal Tank Volume = 6,120 tail fuel transfer = 4,000 gal

CWT Fuel Volume = 10,000 gal Tank Volume = 10,200

Tail Tank Fuel Volume = 2,000 gal Tank Volume = 2,040

Fuel Distribution (Generic Tanks)

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

Main 

Tank 2 

Fuel 

Remainin

CWT 

Fuel 

Remainin

g

Tail Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 278650 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 53272 26636 26636 0 0 0 0.0

51.0 0.9 0 0.0 0.000 278650 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 3307 55 53272 26636 26636 0 0 0 0.0

60.0 1.0 0 0.0 0.000 278154 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 29301 488 52776 26388 26388 0 0 0 0.0

61.6 1.0 1500 3.3 0.388 277359 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 29301 488 51980 25990 25990 0 0 3946 12.0

61.8 1.0 2000 3.8 0.391 277297 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 29290 488 51918 25959 25959 0 0 3960 12.0

62.0 1.0 3000 4.9 0.398 277173 -10 31 49 62 78 88 98 4 46 65 79 96 106 116 29323 489 51795 25897 25897 0 0 3995 11.9

62.3 1.0 4000 6.0 0.406 277052 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 29259 488 51674 25837 25837 0 0 4018 11.8

62.5 1.0 5000 7.1 0.413 276931 -12 26 43 56 71 80 90 4 43 60 73 89 99 109 29458 491 51552 25776 25776 0 0 4092 11.9

62.8 1.0 6000 8.2 0.420 276812 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 29385 490 51433 25717 25717 0 0 4117 11.8

63.0 1.1 7000 9.3 0.428 276693 -13 22 37 49 64 73 81 3 40 56 68 83 92 101 28997 483 51314 25657 25657 0 0 4071 11.6

63.3 1.1 8000 10.4 0.436 276576 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 28587 476 51197 25599 25599 0 0 4012 11.3

63.5 1.1 9000 11.6 0.444 276457 -15 18 32 43 56 65 73 2 37 51 63 77 85 94 28307 472 51078 25539 25539 0 0 3975 11.1

63.8 1.1 10000 12.8 0.452 276338 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 27987 466 50959 25480 25480 0 0 3931 10.9

64.1 1.1 10000 14.6 0.541 276172 -16 16 29 40 52 61 69 10 43 58 69 82 91 100 28455 474 50794 25397 25397 0 0 4035 8.2

64.4 1.1 11000 16.1 0.551 276053 -17 13 26 37 49 57 64 10 42 56 67 80 88 96 27875 465 50675 25337 25337 0 0 3934 7.9

64.6 1.1 12000 17.6 0.561 275937 -18 11 23 33 45 53 60 10 41 54 65 77 85 93 27278 455 50558 25279 25279 0 0 3825 7.6

64.9 1.1 13000 19.2 0.571 275815 -18 9 21 30 41 49 56 10 40 52 62 74 82 90 26662 444 50437 25218 25218 0 0 3711 7.4

65.2 1.1 14000 20.8 0.582 275696 -19 7 18 27 38 45 52 11 38 50 60 71 79 86 26056 434 50318 25159 25159 0 0 3592 7.1

65.4 1.1 15000 22.5 0.593 275575 -20 5 15 24 34 41 47 11 37 48 58 69 76 83 25468 424 50197 25098 25098 0 0 3472 6.8

65.7 1.1 16000 24.4 0.604 275452 -21 2 12 21 30 37 43 11 36 47 56 66 73 80 24983 416 50073 25037 25037 0 0 3368 6.6

66.0 1.1 17000 26.3 0.615 275328 -22 0 9 18 26 33 39 11 35 45 54 63 70 77 24464 408 49950 24975 24975 0 0 3259 6.3

66.3 1.1 18000 28.3 0.627 275200 -23 -2 7 14 23 29 35 12 34 43 52 61 67 73 23902 398 49822 24911 24911 0 0 3140 6.1

66.7 1.1 19000 30.4 0.639 275072 -23 -4 4 11 19 25 30 12 33 42 50 58 64 70 23303 388 49694 24847 24847 0 0 3012 5.8

67.0 1.1 20000 32.6 0.651 274942 -24 -6 1 8 15 21 26 13 32 40 48 56 61 67 22672 378 49564 24782 24782 0 0 2876 5.5

67.4 1.1 21000 35.0 0.664 274810 -28 -10 -3 5 12 17 23 10 30 38 45 53 59 65 22300 372 49432 24716 24716 0 0 2783 5.3

67.7 1.1 22000 37.5 0.677 274676 -31 -13 -6 1 8 14 19 8 27 35 43 51 57 63 21854 364 49297 24649 24649 0 0 2677 5.1

68.1 1.1 23000 40.1 0.690 274539 -35 -17 -10 -3 5 10 15 5 25 33 41 49 55 61 21343 356 49160 24580 24580 0 0 2560 4.9

68.5 1.1 24000 42.9 0.703 274398 -39 -21 -13 -6 1 6 12 3 23 31 39 47 53 58 20772 346 49019 24510 24510 0 0 2433 4.7

68.9 1.1 25000 45.9 0.717 274254 -42 -24 -17 -10 -3 3 8 1 21 29 37 44 50 56 20152 336 48876 24438 24438 0 0 2300 4.4

69.4 1.2 26000 49.2 0.731 274107 -46 -28 -21 -13 -6 -1 5 -1 18 26 34 42 48 54 19700 328 48728 24364 24364 0 0 2190 4.2

69.8 1.2 27000 52.6 0.745 273955 -49 -31 -24 -17 -10 -4 1 -4 16 24 32 40 46 52 19220 320 48576 24288 24288 0 0 2073 4.0

70.3 1.2 28000 56.3 0.760 273796 -53 -35 -28 -20 -13 -8 -2 -6 14 22 30 38 44 50 18715 312 48417 24209 24209 0 0 1952 3.7

70.9 1.2 29000 60.3 0.775 273635 -56 -38 -31 -24 -17 -11 -6 -8 12 20 28 36 42 48 18184 303 48256 24128 24128 0 0 1835 3.5

71.4 1.2 29959 64.5 0.790 273472 -60 -42 -35 -27 -20 -15 -9 -10 10 18 27 35 41 47 17657 294 48093 24047 24047 0 0 1709 3.2

71.4 1.2 29959 64.5 0.790 273472 -60 -42 -35 -27 -20 -15 -9 -10 10 18 27 35 41 47 17657 294 48093 24047 24047 0 0 2417 4.1

71.4 1.2 30000 64.6 0.790 273467 -60 -42 -35 -28 -20 -15 -10 -10 10 18 26 34 41 47 17635 294 48089 24044 24044 0 0 2413 4.1

71.9 1.2 31000 67.9 0.790 273344 -64 -46 -38 -31 -24 -19 -13 -14 6 14 22 30 37 43 16953 283 47965 23983 23983 0 0 2266 4.1

72.3 1.2 32000 71.5 0.790 273218 -67 -49 -42 -35 -27 -22 -17 -18 2 10 18 26 33 39 16285 271 47840 23920 23920 0 0 2115 4.1

72.8 1.2 33000 75.2 0.790 273086 -71 -53 -45 -38 -31 -26 -20 -22 -2 6 14 22 29 35 15684 261 47708 23854 23854 0 0 1960 4.0

73.3 1.2 34000 79.3 0.790 272949 -74 -56 -49 -42 -35 -29 -24 -26 -6 2 10 18 24 31 15084 251 47571 23785 23785 0 0 1796 4.0

73.9 1.2 35000 83.7 0.790 272806 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 14493 242 47428 23714 23714 0 0 1628 4.0

73.9 1.2 35000 83.7 0.790 272808 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9259 154 47428 23714 23714 0 0 0 2.0

99.0 1.6 35000 273.9 0.790 268961 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9156 153 43581 21790 21790 0 0 0 1.9

113.5 1.9 35000 383.9 0.790 266757 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9098 152 41376 20688 20688 0 0 0 1.9

128.1 2.1 35000 494.6 0.790 264552 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9041 151 39171 19586 19586 0 0 0 1.9

142.7 2.4 35000 606.0 0.790 262347 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8986 150 36967 18483 18483 0 0 0 1.8

157.5 2.6 35000 718.0 0.790 260143 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8931 149 34762 17381 17381 0 0 0 1.8

172.4 2.9 35000 830.8 0.790 257938 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8876 148 32558 16279 16279 0 0 0 1.8

176.1 2.9 35000 859.3 0.790 257383 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8862 148 32002 16001 16001 0 0 0 1.8

176.1 2.9 35000 859.3 0.790 257383 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 14493 242 32002 16001 16001 0 0 1867 4.1

176.7 2.9 36000 863.6 0.790 257250 -81 -63 -56 -49 -42 -36 -31 -34 -14 -6 2 10 16 23 13823 230 31870 15935 15935 0 0 1675 4.0

176.7 2.9 36089 864.0 0.790 257237 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13766 229 31856 15928 15928 0 0 1519 3.9

176.7 2.9 36089 864.0 0.790 257237 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13766 229 31856 15928 15928 0 0 1519 3.9

177.4 3.0 37000 868.8 0.790 257094 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13243 221 31713 15857 15857 0 0 1358 3.8

178.2 3.0 38000 874.7 0.790 256924 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 12690 211 31543 15772 15772 0 0 1173 3.8

179.1 3.0 39000 881.9 0.790 256728 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 12039 201 31347 15674 15674 0 0 945 3.7

179.1 3.0 39000 881.9 0.790 256730 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8788 146 31347 15674 15674 0 0 0 2.5

201.1 3.4 39000 1048.2 0.790 253529 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8653 144 28146 14073 14073 0 0 0 2.5

216.5 3.6 39000 1164.3 0.790 251324 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8565 143 25942 12971 12971 0 0 0 2.5

232.0 3.9 39000 1281.5 0.790 249120 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8477 141 23737 11868 11868 0 0 0 2.4

247.7 4.1 39000 1399.9 0.790 246915 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8391 140 21532 10766 10766 0 0 0 2.4

263.5 4.4 39000 1519.5 0.790 244711 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8316 139 19328 9664 9664 0 0 0 2.3

279.5 4.7 39000 1640.2 0.790 242506 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8243 137 17123 8562 8562 0 0 0 2.3

295.6 4.9 39000 1761.9 0.790 240301 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8170 136 14919 7459 7459 0 0 0 2.3

310.0 5.2 39000 1870.0 0.790 238359 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8106 135 12976 6488 6488 0 0 0 2.2

310.0 5.2 39000 1870.0 0.790 238359 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 2088 35 12976 6488 6488 0 0 -2340 -0.7

310.4 5.2 38036 1873.1 0.790 238344 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 2103 35 12961 6480 6480 0 0 -2355 -0.9

310.4 5.2 38035 1873.1 0.790 238344 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 2103 35 12961 6480 6480 0 0 -1708 -0.1

311.0 5.2 37000 1877.6 0.773 238324 -82 -64 -56 -49 -42 -37 -31 -37 -16 -8 0 8 14 20 2061 34 12941 6471 6471 0 0 -1689 -0.1

311.5 5.2 36089 1881.6 0.758 238304 -82 -64 -56 -49 -42 -37 -31 -38 -18 -10 -2 6 12 18 1993 33 12921 6461 6461 0 0 -1687 0.0

311.5 5.2 36089 1881.6 0.758 238304 -82 -64 -56 -49 -42 -37 -31 -38 -18 -10 -2 6 12 18 1993 33 12921 6461 6461 0 0 -1788 -0.1

Airplane Standards (3).xls, Profile-med-med 7/8/98
Charts-med-med

Medium Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-med-med 7/8/98
Medium Commercial Transport

Medium Range Mission

312.1 5.2 35000 1886.0 0.741 238284 -78 -60 -53 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 1916 32 12901 6451 6451 0 0 -1786 -0.1

312.7 5.2 34000 1889.9 0.726 238267 -74 -56 -49 -42 -35 -29 -24 -34 -14 -6 2 10 16 22 1836 31 12884 6442 6442 0 0 -1793 -0.1

313.2 5.2 33000 1893.8 0.711 238249 -71 -53 -45 -38 -31 -26 -20 -31 -12 -4 4 12 18 24 1750 29 12866 6433 6433 0 0 -1807 -0.2

313.8 5.2 32000 1897.5 0.696 238233 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 1656 28 12851 6425 6425 0 0 -1828 -0.1

314.3 5.2 31000 1901.2 0.682 238218 -64 -46 -38 -31 -24 -19 -13 -27 -7 1 9 17 23 28 1675 28 12835 6418 6418 0 0 -1814 -0.2

314.9 5.2 30000 1904.9 0.668 238203 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 1698 28 12820 6410 6410 0 0 -1800 -0.2

315.4 5.3 29000 1908.5 0.655 238187 -56 -38 -31 -24 -17 -11 -6 -22 -2 6 13 21 27 33 1709 28 12804 6402 6402 0 0 -1789 -0.2

316.0 5.3 28000 1912.1 0.641 238172 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 1709 28 12789 6394 6394 0 0 -1781 -0.1

316.6 5.3 27000 1915.6 0.628 238156 -49 -31 -24 -17 -10 -4 1 -17 3 10 18 26 32 37 1746 29 12773 6387 6387 0 0 -1762 -0.2

317.1 5.3 26000 1919.2 0.616 238139 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 1786 30 12756 6378 6378 0 0 -1743 -0.2

317.7 5.3 25000 1922.7 0.604 238121 -42 -24 -17 -10 -3 3 8 -12 8 15 23 31 37 42 1823 30 12738 6369 6369 0 0 -1725 -0.2

318.3 5.3 24000 1926.2 0.592 238103 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 1861 31 12721 6360 6360 0 0 -1707 -0.2

318.9 5.3 23000 1929.7 0.580 238086 -35 -17 -10 -3 5 10 15 -6 13 20 28 36 42 47 1896 32 12703 6351 6351 0 0 -1690 -0.2

319.5 5.3 22000 1933.1 0.569 238068 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 1922 32 12685 6343 6343 0 0 -1677 -0.2

320.1 5.3 21000 1936.6 0.558 238048 -28 -10 -3 5 12 17 23 -1 18 26 33 41 47 53 1940 32 12665 6333 6333 0 0 -1666 -0.2

320.7 5.3 20000 1939.9 0.547 238028 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 1951 33 12646 6323 6323 0 0 -1658 -0.2

321.3 5.4 19000 1943.3 0.536 238009 -23 -4 4 11 19 25 30 2 22 30 38 47 53 59 2006 33 12626 6313 6313 0 0 -1638 -0.2

321.9 5.4 18000 1946.7 0.526 237989 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 2059 34 12606 6303 6303 0 0 -1619 -0.2

322.5 5.4 17000 1950.0 0.516 237967 -22 0 9 18 26 33 39 2 25 34 43 52 59 65 2110 35 12584 6292 6292 0 0 -1602 -0.2

323.2 5.4 16000 1953.3 0.506 237947 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 2154 36 12564 6282 6282 0 0 -1588 -0.2

323.8 5.4 15000 1956.6 0.497 237923 -20 5 15 24 34 41 47 2 28 38 48 58 65 72 2202 37 12540 6270 6270 0 0 -1572 -0.3

324.4 5.4 14000 1959.9 0.487 237901 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 2251 38 12518 6259 6259 0 0 -1556 -0.3

325.1 5.4 13000 1963.2 0.478 237876 -18 9 21 30 41 49 56 2 30 43 53 64 72 79 2295 38 12493 6247 6247 0 0 -1541 -0.3

325.7 5.4 12000 1966.4 0.469 237850 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 2337 39 12467 6234 6234 0 0 -1528 -0.3

326.4 5.4 11000 1969.7 0.461 237826 -17 13 26 37 49 57 64 2 33 47 58 70 79 87 2372 40 12443 6221 6221 0 0 -1517 -0.3

327.0 5.5 10000 1972.9 0.452 237799 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 2394 40 12416 6208 6208 0 0 -1511 -0.4

327.0 5.5 10000 1972.9 0.452 237799 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 2394 40 12416 6208 6208 0 0 -1511 -0.4

327.7 5.5 9000 1976.0 0.444 237773 -15 18 32 43 56 65 73 2 37 51 63 77 85 94 2394 40 12390 6195 6195 0 0 -1511 -0.4

328.4 5.5 8000 1979.1 0.436 237746 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 2392 40 12363 6182 6182 0 0 -1513 -0.5

329.0 5.5 7000 1982.2 0.428 237720 -13 22 37 49 64 73 81 3 40 56 68 83 92 101 2429 40 12337 6168 6168 0 0 -1501 -0.5

329.7 5.5 6000 1985.3 0.420 237693 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 2478 41 12310 6155 6155 0 0 -1487 -0.5

330.4 5.5 5000 1988.3 0.413 237665 -12 26 43 56 71 80 90 4 43 60 73 89 99 109 2524 42 12282 6141 6141 0 0 -1473 -0.5

331.1 5.5 4000 1991.3 0.406 237636 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 2568 43 12253 6127 6127 0 0 -1461 -0.5

331.7 5.5 3000 1994.3 0.398 237607 -10 31 49 62 78 88 98 4 46 65 79 96 106 116 2621 44 12225 6112 6112 0 0 -1447 -0.5

332.4 5.5 2000 1997.3 0.391 237577 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 2670 44 12194 6097 6097 0 0 -1433 -0.6

332.8 5.5 1500 1998.8 0.388 237561 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 2692 45 12178 6089 6089 0 0 -1427 -0.6

336.5 5.6 0 1998.8 0.000 237222 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 11839 5919 5919 0 0 0 0.0

366.5 6.1 0 1998.8 0.000 237222 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 11839 5919 5919 0 0 0 0.0

Airplane Standards (3).xls, Profile-med-med 7/8/98
Charts-med-med

Medium Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-med-med 7/8/98
Medium Commercial Transport

Long Range Mission

Ground Time (takeoff) = 60.000 minutes Main 1 Fuel Volume = 6,000 gal Tank Volume = 6,120 Threshold fuel in CWT to trigger

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 6,000 gal Tank Volume = 6,120 tail fuel transfer = 4,000 gal

CWT Fuel Volume = 10,000 gal Tank Volume = 10,200

Tail Tank Fuel Volume = 2,000 gal Tank Volume = 2,040

Fuel Distribution (Generic Tanks)

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

Main 

Tank 2 

Fuel 

Remainin

CWT 

Fuel 

Remainin

g

Tail Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 326138 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 100763 40200 40200 20363 0 0 0.0

51.0 0.9 0 0.0 0.000 326138 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 3307 55 100763 40200 40200 20363 0 0 0.0

60.0 1.0 0 0.0 0.000 325641 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 29301 488 100267 40200 40200 19867 0 0 0.0

61.9 1.0 1500 3.9 0.388 324678 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 29301 488 99304 40200 40200 18904 0 3198 11.3

62.1 1.0 2000 4.6 0.391 324601 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 29290 488 99227 40200 40200 18827 0 3209 11.2

62.4 1.0 3000 5.9 0.398 324449 -10 31 49 62 78 88 98 4 46 65 79 96 106 116 29323 489 99075 40200 40200 18675 0 3237 11.2

62.7 1.0 4000 7.3 0.406 324299 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 29259 488 98925 40200 40200 18525 0 3254 11.1

63.0 1.1 5000 8.6 0.413 324151 -12 26 43 56 71 80 90 4 43 60 73 89 99 109 29458 491 98777 40200 40200 18377 0 3316 11.1

63.3 1.1 6000 9.9 0.420 324003 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 29385 490 98629 40200 40200 18229 0 3334 11.1

63.6 1.1 7000 11.3 0.428 323856 -13 22 37 49 64 73 81 3 40 56 68 83 92 101 28997 483 98482 40200 40200 18082 0 3293 10.9

63.9 1.1 8000 12.7 0.436 323708 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 28587 476 98334 40200 40200 17934 0 3240 10.7

64.2 1.1 9000 14.2 0.444 323563 -15 18 32 43 56 65 73 2 37 51 63 77 85 94 28307 472 98188 40200 40200 17788 0 3206 10.5

64.6 1.1 10000 15.7 0.452 323415 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 27987 466 98041 40200 40200 17641 0 3166 10.4

65.0 1.1 10000 18.0 0.541 323210 -16 16 29 40 52 61 69 10 43 58 69 82 91 100 28455 474 97836 40200 40200 17436 0 3299 7.6

65.3 1.1 11000 19.7 0.551 323066 -17 13 26 37 49 57 64 10 42 56 67 80 88 96 27875 465 97692 40200 40200 17292 0 3211 7.4

65.6 1.1 12000 21.6 0.561 322921 -18 11 23 33 45 53 60 10 41 54 65 77 85 93 27278 455 97547 40200 40200 17147 0 3116 7.1

65.9 1.1 13000 23.5 0.571 322775 -18 9 21 30 41 49 56 10 40 52 62 74 82 90 26662 444 97401 40200 40200 17001 0 3016 6.9

66.3 1.1 14000 25.6 0.582 322626 -19 7 18 27 38 45 52 11 38 50 60 71 79 86 26056 434 97252 40200 40200 16852 0 2912 6.7

66.6 1.1 15000 27.7 0.593 322476 -20 5 15 24 34 41 47 11 37 48 58 69 76 83 25468 424 97102 40200 40200 16702 0 2807 6.4

67.0 1.1 16000 30.0 0.604 322324 -21 2 12 21 30 37 43 11 36 47 56 66 73 80 24983 416 96949 40200 40200 16549 0 2716 6.2

67.4 1.1 17000 32.3 0.615 322169 -22 0 9 18 26 33 39 11 35 45 54 63 70 77 24464 408 96795 40200 40200 16395 0 2621 6.0

67.7 1.1 18000 34.8 0.627 322013 -23 -2 7 14 23 29 35 12 34 43 52 61 67 73 23902 398 96639 40200 40200 16239 0 2517 5.8

68.2 1.1 19000 37.5 0.639 321854 -23 -4 4 11 19 25 30 12 33 42 50 58 64 70 23303 388 96480 40200 40200 16080 0 2406 5.5

68.6 1.1 20000 40.3 0.651 321689 -24 -6 1 8 15 21 26 13 32 40 48 56 61 67 22672 378 96315 40200 40200 15915 0 2287 5.3

69.0 1.2 21000 43.3 0.664 321523 -28 -10 -3 5 12 17 23 10 30 38 45 53 59 65 22300 372 96149 40200 40200 15749 0 2205 5.1

69.5 1.2 22000 46.4 0.677 321351 -31 -13 -6 1 8 14 19 8 27 35 43 51 57 63 21854 364 95977 40200 40200 15577 0 2112 4.9

70.0 1.2 23000 49.8 0.690 321177 -35 -17 -10 -3 5 10 15 5 25 33 41 49 55 61 21343 356 95803 40200 40200 15403 0 2010 4.7

70.5 1.2 24000 53.4 0.703 320999 -39 -21 -13 -6 1 6 12 3 23 31 39 47 53 58 20772 346 95625 40200 40200 15225 0 1900 4.5

71.0 1.2 25000 57.2 0.717 320813 -42 -24 -17 -10 -3 3 8 1 21 29 37 44 50 56 20152 336 95439 40200 40200 15039 0 1785 4.3

71.6 1.2 26000 61.4 0.731 320622 -46 -28 -21 -13 -6 -1 5 -1 18 26 34 42 48 54 19700 328 95248 40200 40200 14848 0 1691 4.1

72.2 1.2 27000 65.9 0.745 320425 -49 -31 -24 -17 -10 -4 1 -4 16 24 32 40 46 52 19220 320 95051 40200 40200 14651 0 1591 3.9

72.9 1.2 28000 70.7 0.760 320218 -53 -35 -28 -20 -13 -8 -2 -6 14 22 30 38 44 50 18715 312 94844 40200 40200 14444 0 1491 3.7

73.6 1.2 29000 76.0 0.775 320004 -56 -38 -31 -24 -17 -11 -6 -8 12 20 28 36 42 48 18184 303 94630 40200 40200 14230 0 1384 3.5

74.3 1.2 29959 81.6 0.790 319788 -60 -42 -35 -27 -20 -15 -9 -10 10 18 27 35 41 47 17657 294 94414 40200 40200 14014 0 1269 3.2

74.3 1.2 29959 81.6 0.790 319788 -60 -42 -35 -27 -20 -15 -9 -10 10 18 27 35 41 47 17657 294 94414 40200 40200 14014 0 1795 3.9

74.3 1.2 30000 81.7 0.790 319782 -60 -42 -35 -28 -20 -15 -10 -10 10 18 26 34 41 47 17635 294 94408 40200 40200 14008 0 1790 3.9

74.9 1.2 31000 86.3 0.790 319614 -64 -46 -38 -31 -24 -19 -13 -14 6 14 22 30 37 43 16953 283 94240 40200 40200 13840 0 1638 3.9

75.5 1.3 32000 91.2 0.790 319438 -67 -49 -42 -35 -27 -22 -17 -18 2 10 18 26 33 39 16285 271 94064 40200 40200 13664 0 1480 3.9

76.2 1.3 33000 96.7 0.790 319246 -71 -53 -45 -38 -31 -26 -20 -22 -2 6 14 22 29 35 15684 261 93872 40200 40200 13472 0 1313 3.9

77.1 1.3 34000 103.0 0.790 319036 -74 -56 -49 -42 -35 -29 -24 -26 -6 2 10 18 24 31 15084 251 93662 40200 40200 13262 0 1128 3.8

78.0 1.3 35000 110.4 0.790 318794 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 14493 242 93420 40200 40200 13020 0 914 3.8

78.0 1.3 35000 110.4 0.790 318798 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10924 182 93420 40200 40200 13020 0 0 2.7

97.6 1.6 35000 259.1 0.790 315258 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10758 179 89879 40200 40200 9479 0 0 2.6

110.0 1.8 35000 352.9 0.790 313053 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10655 178 87675 40200 40200 7275 0 0 2.6

122.5 2.0 35000 447.5 0.790 310849 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10556 176 85470 40200 40200 5070 0 0 2.5

135.1 2.3 35000 543.1 0.790 308644 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10461 174 83266 40200 40200 2866 0 0 2.5

147.8 2.5 35000 639.5 0.790 306439 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10373 173 81061 40200 40200 661 0 0 2.5

160.6 2.7 35000 736.7 0.790 304235 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10284 171 78856 39428 39428 0 0 0 2.4

173.5 2.9 35000 834.7 0.790 302030 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10196 170 76652 38326 38326 0 0 0 2.4

186.5 3.1 35000 933.6 0.790 299826 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10108 168 74447 37224 37224 0 0 0 2.4

199.6 3.3 35000 1033.3 0.790 297621 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 10031 167 72243 36121 36121 0 0 0 2.4

212.9 3.5 35000 1133.7 0.790 295416 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9956 166 70038 35019 35019 0 0 0 2.3

226.2 3.8 35000 1234.9 0.790 293212 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9883 165 67833 33917 33917 0 0 0 2.3

239.6 4.0 35000 1336.9 0.790 291007 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9810 164 65629 32814 32814 0 0 0 2.3

253.2 4.2 35000 1439.6 0.790 288803 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9738 162 63424 31712 31712 0 0 0 2.2

266.8 4.4 35000 1543.1 0.790 286598 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9667 161 61220 30610 30610 0 0 0 2.2

280.5 4.7 35000 1647.3 0.790 284393 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9599 160 59015 29507 29507 0 0 0 2.2

294.4 4.9 35000 1752.2 0.790 282189 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9530 159 56810 28405 28405 0 0 0 2.1

308.3 5.1 35000 1857.9 0.790 279984 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9464 158 54606 27303 27303 0 0 0 2.1

322.3 5.4 35000 1964.4 0.790 277780 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9396 157 52401 26201 26201 0 0 0 2.1

336.5 5.6 35000 2071.6 0.790 275575 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9336 156 50197 25098 25098 0 0 0 2.0

350.7 5.8 35000 2179.5 0.790 273370 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9275 155 47992 23996 23996 0 0 0 2.0

365.0 6.1 35000 2288.0 0.790 271166 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9215 154 45787 22894 22894 0 0 0 2.0

379.4 6.3 35000 2397.3 0.790 268961 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9156 153 43583 21791 21791 0 0 0 1.9

393.9 6.6 35000 2507.3 0.790 266757 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9098 152 41378 20689 20689 0 0 0 1.9

408.4 6.8 35000 2618.0 0.790 264552 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 9041 151 39174 19587 19587 0 0 0 1.9

423.1 7.1 35000 2729.4 0.790 262347 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8986 150 36969 18484 18484 0 0 0 1.8

437.9 7.3 35000 2841.4 0.790 260143 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8931 149 34764 17382 17382 0 0 0 1.8

452.7 7.5 35000 2954.2 0.790 257938 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8876 148 32560 16280 16280 0 0 0 1.8

456.4 7.6 35000 2981.8 0.790 257400 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 8862 148 32022 16011 16011 0 0 0 1.8

456.4 7.6 35000 2981.8 0.790 257400 -78 -60 -53 -45 -38 -33 -27 -30 -10 -2 6 14 20 27 14493 242 32022 16011 16011 0 0 1867 4.1

Airplane Standards (3).xls, Profile-med-long 7/8/98
Charts-med-long

Medium Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Altitude (ft)

Pressure Alt

Medium Airplane

Long Range Mission

0

20,000

40,000

60,000

80,000

100,000

120,000

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

#REF!

#REF!

Medium Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Medium Airplane

Long Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11 12

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-med-long 7/8/98
Large Commercial Transport

Short Range Mission

Ground Time (takeoff) = 90.000 minutes Main 1 Fuel Volume = 13,000 gal Tank Volume = 13,260 Threshold fuel in CWT to trigger Main 1/4 =

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 13,000 gal Tank Volume = 13,260 tail fuel transfer = 10,000 gal Main 2/3 =

CWT Fuel Volume = 25,000 gal Tank Volume = 25,500

Tail Tank Fuel Volume = 3,000 gal Tank Volume = 3,060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Tail Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 574995 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 114775 57388 57388 0 0 0

81.0 1.4 0 0.0 0.000 574995 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 6000 100 114775 57388 57388 0 0 0

90.0 1.5 0 0.0 0.000 574095 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 75955 1266 113875 56938 56938 0 0 0

92.0 1.5 1500 4.9 0.388 571691 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 75955 1266 111471 55736 55736 0 0 4629 12.6

92.1 1.5 2000 5.4 0.391 571554 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 75487 1258 111334 55667 55667 0 0 4613 12.5

92.5 1.5 4000 7.2 0.406 571011 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 73623 1227 110791 55396 55396 0 0 4537 12.2

93.0 1.5 6000 9.2 0.420 570471 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 71491 1192 110251 55126 55126 0 0 4425 11.8

93.5 1.6 8000 11.3 0.436 569933 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 69018 1150 109713 54857 54857 0 0 4274 11.3

93.9 1.6 10000 13.5 0.452 569394 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 66503 1108 109174 54587 54587 0 0 4114 10.8

93.9 1.6 10000 13.5 0.452 569394 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 66503 1108 109174 54587 54587 0 0 0 2.8

94.4 1.6 10000 16.3 0.584 568823 -16 16 29 40 52 61 69 14 48 62 74 87 96 105 69827 1164 108603 54302 54302 0 0 0 1.5

94.4 1.6 10000 16.3 0.584 568823 -16 16 29 40 52 61 69 14 48 62 74 87 96 105 69827 1164 108603 54302 54302 0 0 4429 8.2

94.9 1.6 12000 19.2 0.605 568293 -18 11 23 33 45 53 60 15 46 59 70 82 90 98 66844 1114 108073 54037 54037 0 0 4170 7.7

95.4 1.6 14000 22.4 0.628 567752 -19 7 18 27 38 45 52 15 44 55 65 77 84 92 63860 1064 107532 53766 53766 0 0 3896 7.1

95.9 1.6 16000 26.0 0.651 567199 -21 2 12 21 30 37 43 16 42 52 62 72 79 86 61097 1018 106979 53490 53490 0 0 3640 6.6

96.5 1.6 18000 29.9 0.676 566633 -23 -2 7 14 23 29 35 17 40 49 58 67 73 80 58500 975 106413 53207 53207 0 0 3403 6.1

97.1 1.6 20000 34.2 0.701 566050 -24 -6 1 8 15 21 26 18 38 46 54 62 68 74 55160 919 105830 52915 52915 0 0 3098 5.5

97.8 1.6 22000 39.0 0.728 565449 -31 -13 -6 1 8 14 19 14 34 42 50 58 64 70 53553 893 105229 52615 52615 0 0 2932 5.1

98.5 1.6 24000 44.4 0.756 564828 -39 -21 -13 -6 1 6 12 10 30 38 46 54 60 66 51555 859 104608 52304 52304 0 0 2716 4.7

99.3 1.7 26000 50.3 0.785 564179 -46 -28 -21 -13 -6 -1 5 5 26 34 42 50 56 62 49211 820 103959 51980 51980 0 0 2466 4.2

100.1 1.7 28000 57.2 0.816 563491 -53 -35 -28 -20 -13 -8 -2 1 22 30 38 46 52 58 46567 776 103271 51636 51636 0 0 2183 3.7

101.1 1.7 30000 65.4 0.848 562740 -60 -42 -35 -28 -20 -15 -10 -2 18 26 35 43 49 55 43799 730 102520 51260 51260 0 0 1847 3.1

101.2 1.7 30097 65.9 0.850 562701 -60 -42 -35 -28 -21 -15 -10 -3 18 26 34 43 49 55 43653 728 102481 51241 51241 0 0 1828 3.1

101.2 1.7 30097 65.9 0.850 562701 -60 -42 -35 -28 -21 -15 -10 -3 18 26 34 43 49 55 43653 728 102481 51241 51241 0 0 2700 4.1

101.9 1.7 32000 72.1 0.850 562178 -67 -49 -42 -35 -27 -22 -17 -10 10 18 27 35 41 47 40354 673 101958 50979 50979 0 0 2397 4.0

102.8 1.7 34000 79.5 0.850 561600 -74 -56 -49 -42 -35 -29 -24 -19 2 10 19 27 33 39 36957 616 101380 50690 50690 0 0 2069 4.0

103.9 1.7 36000 88.2 0.850 560973 -81 -63 -56 -49 -42 -36 -31 -27 -6 2 10 19 25 31 33491 558 100753 50377 50377 0 0 1699 3.9

103.9 1.7 36089 88.7 0.850 560944 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 33334 556 100724 50362 50362 0 0 1681 3.9

103.9 1.7 36089 88.7 0.850 560944 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 33334 556 100724 50362 50362 0 0 1519 3.7

105.4 1.8 38000 100.4 0.850 560182 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 30422 507 99962 49981 49981 0 0 1175 3.6

106.3 1.8 39000 107.9 0.850 559723 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 29009 483 99503 49752 49752 0 0 994 3.6

112.0 1.9 39000 153.9 0.850 557761 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20758 346 97541 48771 48771 0 0 0 2.4

126.7 2.1 39000 273.7 0.850 552682 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20584 343 92462 46231 46231 0 0 0 2.4

141.6 2.4 39000 394.5 0.850 547603 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20416 340 87383 43692 43692 0 0 0 2.4

156.6 2.6 39000 516.3 0.850 542525 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20253 338 82305 41153 41153 0 0 0 2.3

171.7 2.9 39000 639.0 0.850 537446 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20096 335 77226 38613 38613 0 0 0 2.3

186.9 3.1 39000 762.7 0.850 532367 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19940 332 72147 36074 36074 0 0 0 2.2

202.2 3.4 39000 887.3 0.850 527288 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19789 330 67068 33534 33534 0 0 0 2.2

217.7 3.6 39000 1012.9 0.850 522209 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19641 327 61989 30995 30995 0 0 0 2.2

233.3 3.9 39000 1139.5 0.850 517130 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19494 325 56910 28455 28455 0 0 0 2.1

249.0 4.1 39000 1267.0 0.850 512051 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19351 323 51831 25916 25916 0 0 0 2.1

254.5 4.2 39000 1311.8 0.850 510274 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19302 322 50054 25027 25027 0 0 0 2.1

255.3 4.3 40000 1318.4 0.850 509892 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 27464 458 49672 24836 24836 0 0 1144 3.6

257.5 4.3 42000 1336.1 0.850 508954 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 24874 415 48734 24367 24367 0 0 770 3.5

259.0 4.3 43000 1348.3 0.850 508348 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 23669 394 48128 24064 24064 0 0 585 3.5

266.6 4.4 43000 1410.5 0.850 505898 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19150 319 45678 22839 22839 0 0 0 2.8

275.6 4.6 43000 1483.6 0.850 503037 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19036 317 42817 21409 21409 0 0 0 2.8

284.7 4.7 43000 1557.1 0.850 500175 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18922 315 39955 19978 19978 0 0 0 2.8

293.8 4.9 43000 1631.0 0.850 497314 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18811 314 37094 18547 18547 0 0 0 2.7

302.9 5.0 43000 1705.4 0.850 494453 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18698 312 34233 17117 17117 0 0 0 2.7

312.1 5.2 43000 1780.2 0.850 491591 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18584 310 31371 15686 15686 0 0 0 2.7

321.4 5.4 43000 1855.5 0.850 488730 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18472 308 28510 14255 14255 0 0 0 2.7

322.6 5.4 43000 1865.2 0.850 488363 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18457 308 28143 14072 14072 0 0 0 2.7

322.9 5.4 42000 1867.9 0.850 488349 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 2622 44 28129 14065 14065 0 0 3028 -1.0

323.6 5.4 40000 1873.2 0.850 488319 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 2817 47 28099 14050 14050 0 0 3068 -1.5

324.2 5.4 38000 1878.4 0.850 488288 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 2980 50 28068 14034 14034 0 0 3178 -1.9

324.6 5.4 36672 1881.8 0.850 488267 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 3087 51 28047 14024 14024 0 0 3277 -2.3

324.6 5.4 36672 1881.8 0.850 488267 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 3087 51 28047 14024 14024 0 0 2292 -1.1

324.9 5.4 36089 1883.8 0.840 488254 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17 23 29 3120 52 28034 14017 14017 0 0 2257 -1.1

324.9 5.4 36089 1883.8 0.840 488254 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17 23 29 3120 52 28034 14017 14017 0 0 2417 -1.3

324.9 5.4 36000 1884.1 0.838 488252 -81 -63 -56 -49 -42 -36 -31 -28 -8 1 9 17 23 29 3124 52 28032 14016 14016 0 0 2412 -1.2

325.8 5.4 34000 1890.8 0.805 488208 -74 -56 -49 -42 -35 -29 -24 -24 -4 4 12 20 27 33 3213 54 27988 13994 13994 0 0 2336 -1.1

326.6 5.4 32000 1897.4 0.773 488161 -67 -49 -42 -35 -27 -22 -17 -20 0 8 16 24 30 36 3304 55 27941 13971 13971 0 0 2286 -1.0

327.5 5.5 30000 1903.9 0.742 488111 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28 34 40 3407 57 27891 13946 13946 0 0 2239 -1.0

328.4 5.5 28000 1910.4 0.713 488058 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32 38 44 3571 60 27838 13919 13919 0 0 2180 -0.9

329.3 5.5 26000 1916.9 0.685 488002 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37 42 48 3738 62 27782 13891 13891 0 0 2124 -0.9

330.3 5.5 24000 1923.3 0.659 487941 -39 -21 -13 -6 1 6 12 -2 18 25 33 41 47 53 3926 65 27721 13861 13861 0 0 2066 -0.9

331.3 5.5 22000 1929.7 0.634 487875 -31 -13 -6 1 8 14 19 3 22 30 38 46 52 57 4135 69 27655 13828 13828 0 0 2008 -0.9

332.3 5.5 20000 1936.1 0.610 487803 -24 -6 1 8 15 21 26 8 27 35 43 51 56 62 4346 72 27583 13792 13792 0 0 1954 -0.9

333.3 5.6 18000 1942.4 0.587 487727 -23 -2 7 14 23 29 35 7 30 39 47 56 62 69 4542 76 27507 13754 13754 0 0 1914 -1.0

334.4 5.6 16000 1948.7 0.565 487645 -21 2 12 21 30 37 43 7 32 42 51 61 68 75 4749 79 27425 13713 13713 0 0 1881 -1.1

335.5 5.6 14000 1954.9 0.544 487558 -19 7 18 27 38 45 52 7 34 46 56 67 74 82 5023 84 27338 13669 13669 0 0 1841 -1.1

336.6 5.6 12000 1961.1 0.525 487462 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 5359 89 27242 13621 13621 0 0 1793 -1.2

336.6 5.6 12000 1961.1 0.525 487462 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 5359 89 27242 13621 13621 0 0 1250 -0.3

338.4 5.6 10000 1970.5 0.452 487293 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 5704 95 27073 13537 13537 0 0 976 0.4

338.4 5.6 10000 1970.5 0.452 487293 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 5704 95 27073 13537 13537 0 0 1370 -0.4

Airplane Standards (3).xls, Profile-large-short 7/8/98
Charts-large-short

Large Airplane

Short Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

0 1 2 3 4 5 6 7

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Short Range Mission

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

0 1 2 3 4 5 6 7

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Short Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-large-short 7/8/98
Large Commercial Transport

Medium Range Mission

Ground Time (takeoff) = 90.000 minutes Main 1 Fuel Volume = 13,000 gal Tank Volume = 13,260 Threshold fuel in CWT to trigger

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 13,000 gal Tank Volume = 13,260 tail fuel transfer = 10,000 gal

CWT Fuel Volume = 25,000 gal Tank Volume = 25,500

Tail Tank Fuel Volume = 3,000 gal Tank Volume = 3,060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F)

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95%

0.0 0.0 0 0.0 0.000 675500 -8 37 57 72 90 100 111 -8 37 57 72 90

81.0 1.4 0 0.0 0.000 675500 -8 37 57 72 90 100 111 -8 37 57 72 90

90.0 1.5 0 0.0 0.000 674600 -8 37 57 72 90 100 111 -8 37 57 72 90

92.0 1.5 1500 5.4 0.388 671951 -9 34 53 67 84 94 105 5 49 68 83 100

92.1 1.5 2000 6.0 0.405 671785 -9 33 52 65 82 92 103 6 49 68 82 100

92.7 1.5 4000 8.3 0.420 671124 -11 29 46 59 75 84 94 5 46 64 77 94

93.2 1.6 6000 10.8 0.435 670466 -13 24 40 53 67 76 86 4 43 59 72 87

93.8 1.6 8000 13.5 0.451 669807 -14 20 35 46 60 69 77 4 39 55 67 81

94.3 1.6 10000 16.3 0.468 669146 -16 16 29 40 52 61 69 3 36 50 62 75

94.3 1.6 10000 16.3 0.468 669146 -16 16 29 40 52 61 69 3 36 50 62 75

95.0 1.6 10000 20.0 0.602 668409 -16 16 29 40 52 61 69 16 50 65 76 90

95.0 1.6 10000 20.0 0.602 668409 -16 16 29 40 52 61 69 16 50 65 76 90

95.6 1.6 12000 23.7 0.624 667754 -18 11 23 33 45 53 60 17 48 61 72 84

96.2 1.6 14000 27.8 0.647 667082 -19 7 18 27 38 45 52 18 46 58 68 79

96.8 1.6 16000 32.3 0.671 666390 -21 2 12 21 30 37 43 19 44 55 64 74

97.6 1.6 18000 37.4 0.696 665677 -23 -2 7 14 23 29 35 20 42 52 60 70

98.3 1.6 20000 43.0 0.723 664936 -24 -6 1 8 15 21 26 21 41 49 57 65

99.2 1.7 22000 49.3 0.750 664165 -31 -13 -6 1 8 14 19 17 37 45 53 61

100.1 1.7 24000 56.3 0.779 663360 -39 -21 -13 -6 1 6 12 13 33 41 49 57

101.1 1.7 26000 64.3 0.809 662507 -46 -28 -21 -13 -6 -1 5 8 29 37 45 53

102.2 1.7 28000 73.8 0.840 661583 -53 -35 -28 -20 -13 -8 -2 5 25 33 42 50

102.6 1.7 28599 76.9 0.850 661286 -55 -37 -30 -23 -15 -10 -5 4 24 32 41 49

102.6 1.7 28599 76.9 0.850 661286 -55 -37 -30 -23 -15 -10 -5 4 24 32 41 49

103.3 1.7 30000 82.4 0.850 660799 -60 -42 -35 -28 -20 -15 -10 -2 18 27 35 43

104.3 1.7 32000 91.1 0.850 660063 -67 -49 -42 -35 -27 -22 -17 -10 10 18 27 35

105.6 1.8 34000 101.6 0.850 659250 -74 -56 -49 -42 -35 -29 -24 -19 2 10 19 27

106.3 1.8 35000 107.7 0.850 658800 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

123.8 2.1 35000 250.8 0.850 651689 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

143.2 2.4 35000 408.5 0.850 643927 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

162.7 2.7 35000 567.9 0.850 636164 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

182.4 3.0 35000 728.9 0.850 628401 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

202.3 3.4 35000 891.4 0.850 620639 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

202.7 3.4 35000 894.8 0.850 620477 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23

203.4 3.4 36000 900.6 0.850 620069 -81 -63 -56 -49 -42 -36 -31 -27 -6 2 10 19

203.5 3.4 36089 901.2 0.850 620031 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

203.5 3.4 36089 901.2 0.850 620031 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

205.5 3.4 38000 917.5 0.850 618978 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

206.9 3.4 39000 929.1 0.850 618279 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

219.1 3.7 39000 1027.7 0.850 613629 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

232.4 3.9 39000 1136.3 0.850 608550 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

245.9 4.1 39000 1245.9 0.850 603471 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

259.5 4.3 39000 1356.5 0.850 598392 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

273.3 4.6 39000 1468.1 0.850 593313 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

287.1 4.8 39000 1580.8 0.850 588234 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

301.1 5.0 39000 1694.4 0.850 583155 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

315.2 5.3 39000 1809.2 0.850 578077 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

329.5 5.5 39000 1924.9 0.850 572998 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

343.9 5.7 39000 2041.7 0.850 567919 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

358.4 6.0 39000 2159.4 0.850 562840 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

373.0 6.2 39000 2278.2 0.850 557761 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

387.7 6.5 39000 2398.0 0.850 552682 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

402.6 6.7 39000 2518.8 0.850 547603 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

417.6 7.0 39000 2640.6 0.850 542525 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

432.7 7.2 39000 2763.3 0.850 537446 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

447.9 7.5 39000 2887.0 0.850 532367 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

463.2 7.7 39000 3011.7 0.850 527288 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

478.7 8.0 39000 3137.2 0.850 522209 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

494.3 8.2 39000 3263.8 0.850 517130 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

510.0 8.5 39000 3391.3 0.850 512051 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

525.8 8.8 39000 3519.7 0.850 506972 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

541.7 9.0 39000 3649.0 0.850 501893 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

557.7 9.3 39000 3779.3 0.850 496815 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

569.5 9.5 39000 3875.2 0.850 493096 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

569.8 9.5 38000 3877.8 0.850 493080 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

570.3 9.5 36672 3881.2 0.850 493059 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

570.3 9.5 36672 3881.2 0.850 493059 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18

570.5 9.5 36089 3883.3 0.840 493046 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17

570.5 9.5 36089 3883.3 0.840 493046 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17

570.6 9.5 36000 3883.6 0.838 493044 -81 -63 -56 -49 -42 -36 -31 -28 -8 1 9 17

571.4 9.5 34000 3890.2 0.805 492999 -74 -56 -49 -42 -35 -29 -24 -24 -4 4 12 20

572.3 9.5 32000 3896.9 0.773 492952 -67 -49 -42 -35 -27 -22 -17 -20 0 8 16 24

573.2 9.6 30000 3903.4 0.742 492902 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28

574.1 9.6 28000 3910.0 0.713 492850 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32

575.0 9.6 26000 3916.4 0.685 492793 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37

576.0 9.6 24000 3922.9 0.659 492731 -39 -21 -13 -6 1 6 12 -2 18 25 33 41

576.9 9.6 22000 3929.3 0.634 492665 -31 -13 -6 1 8 14 19 3 22 30 38 46

578.0 9.6 20000 3935.8 0.610 492593 -24 -6 1 8 15 21 26 8 27 35 43 51

579.0 9.6 18000 3942.1 0.587 492516 -23 -2 7 14 23 29 35 7 30 39 47 56

580.1 9.7 16000 3948.4 0.565 492434 -21 2 12 21 30 37 43 7 32 42 51 61

581.1 9.7 14000 3954.7 0.544 492346 -19 7 18 27 38 45 52 7 34 46 56 67

582.2 9.7 12000 3960.9 0.525 492251 -18 11 23 33 45 53 60 7 37 50 61 73

582.2 9.7 12000 3960.9 0.525 492251 -18 11 23 33 45 53 60 7 37 50 61 73

584.1 9.7 10000 3970.3 0.452 492081 -16 16 29 40 52 61 69 2 35 49 60 73

584.1 9.7 10000 3970.3 0.452 492081 -16 16 29 40 52 61 69 2 35 49 60 73

585.6 9.8 8000 3977.3 0.436 491939 -14 20 35 46 60 69 77 3 38 53 65 80

587.1 9.8 6000 3984.3 0.420 491790 -13 24 40 53 67 76 86 3 41 58 71 86

588.6 9.8 4000 3991.3 0.406 491635 -11 29 46 59 75 84 94 4 45 63 76 92

590.2 9.8 2000 3998.2 0.391 491475 -9 33 52 65 82 92 103 5 48 67 81 99

590.6 9.8 1500 3999.9 0.388 491434 -9 34 53 67 84 94 105 5 49 68 83 100

594.6 9.9 0 3999.9 0.000 490634 -8 37 57 72 90 100 111 -8 37 57 72 90

599.6 10.0 0 3999.9 0.000 490134 -8 37 57 72 90 100 111 -8 37 57 72 90

624.6 10.4 0 3999.9 0.000 490134 -8 37 57 72 90 100 111 -8 37 57 72 90

Airplane Standards (3).xls, Profile-large-medium 7/8/98
Charts-large-medium

Large Airplane

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Medium Range Mission

0

50,000

100,000

150,000

200,000

250,000

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Medium Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-large-medium 7/8/98
Large Commercial Transport

Long Range Mission

Ground Time (takeoff) = 90.000 minutes Main 1 Fuel Volume = 13,000 gal Tank Volume = 13,260 Threshold fuel in CWT to trigger

Ground Time (landing) = 30.000 minutes Main 2 Fuel Volume = 13,000 gal Tank Volume = 13,260 tail fuel transfer = 10,000 gal

CWT Fuel Volume = 25,000 gal Tank Volume = 25,500

Tail Tank Fuel Volume = 3,000 gal Tank Volume = 3,060

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Tail Fuel 

Remainin

g

Rate of 

Climb / 

Descent

Body 

Pitch 

Attitude

minutes hours feet N. Mi. lbs

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs lbs ft/min degrees

0.0 0.0 0 0.0 0.000 794498 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 334278 87100 87100 160078 0 0

81.0 1.4 0 0.0 0.000 794498 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 6000 100 334278 87100 87100 160078 0 0

90.0 1.5 0 0.0 0.000 793598 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 76691 1278 333378 87100 87100 159178 0 0

92.3 1.5 1500 6.4 0.425 790626 -9 34 53 67 84 94 105 7 52 71 86 104 114 125 76691 1278 330406 87100 87100 156206 0 3130 9.4

92.5 1.5 2000 7.1 0.428 790422 -9 33 52 65 82 92 103 7 51 70 85 102 113 123 76259 1271 330202 87100 87100 156002 0 3117 9.4

93.1 1.6 4000 10.2 0.444 789608 -11 29 46 59 75 84 94 7 48 66 79 96 106 116 74464 1241 329388 87100 87100 155188 0 3054 9.2

93.8 1.6 6000 13.5 0.460 788793 -13 24 40 53 67 76 86 6 45 61 74 90 99 109 72317 1205 328573 87100 87100 154373 0 2956 8.9

94.5 1.6 8000 16.9 0.477 787974 -14 20 35 46 60 69 77 6 42 57 69 83 93 102 69890 1165 327754 87100 87100 153554 0 2829 8.7

95.2 1.6 10000 20.7 0.494 787146 -16 16 29 40 52 61 69 6 39 53 64 77 86 94 67394 1123 326926 87100 87100 152726 0 2695 8.4

95.2 1.6 10000 20.7 0.494 787146 -16 16 29 40 52 61 69 6 39 53 64 77 86 94 67394 1123 326926 87100 87100 152726 0 0 3.6

96.0 1.6 10000 25.5 0.624 786215 -16 16 29 40 52 61 69 19 53 67 79 92 101 110 70690 1178 325995 87100 87100 151795 0 0 2.1

96.0 1.6 10000 25.5 0.624 786215 -16 16 29 40 52 61 69 19 53 67 79 92 101 110 70690 1178 325995 87100 87100 151795 0 2869 6.2

96.7 1.6 12000 30.4 0.647 785380 -18 11 23 33 45 53 60 19 51 64 75 87 95 104 67607 1127 325160 87100 87100 150960 0 2656 5.8

97.5 1.6 14000 35.8 0.670 784515 -19 7 18 27 38 45 52 20 49 61 71 82 90 98 64672 1078 324295 87100 87100 150095 0 2445 5.4

98.4 1.6 16000 41.9 0.695 783615 -21 2 12 21 30 37 43 21 47 58 67 77 85 92 61943 1032 323395 87100 87100 149195 0 2249 5.0

99.3 1.7 18000 48.7 0.721 782679 -23 -2 7 14 23 29 35 23 46 55 64 73 79 86 59848 997 322459 87100 87100 148259 0 2092 4.7

100.3 1.7 20000 56.3 0.748 781695 -24 -6 1 8 15 21 26 24 44 52 60 68 74 80 56856 948 321475 87100 87100 147275 0 1869 4.3

101.4 1.7 22000 65.0 0.776 780656 -31 -13 -6 1 8 14 19 20 40 48 56 65 71 77 55074 918 320436 87100 87100 146236 0 1725 3.9

102.6 1.7 24000 74.8 0.806 779554 -39 -21 -13 -6 1 6 12 16 36 45 53 61 67 73 52962 883 319334 87100 87100 145134 0 1551 3.6

104.0 1.7 26000 86.2 0.836 778359 -46 -28 -21 -13 -6 -1 5 12 33 41 49 57 64 70 50660 844 318139 87100 87100 143939 0 1348 3.2

104.7 1.7 26854 91.7 0.850 777807 -49 -31 -24 -16 -9 -4 2 11 31 39 48 56 62 68 49459 824 317587 87100 87100 143387 0 1237 3.0

104.7 1.7 26854 91.7 0.850 777807 -49 -31 -24 -16 -9 -4 2 11 31 39 48 56 62 68 49459 824 317587 87100 87100 143387 0 1828 3.6

105.3 1.8 28000 97.3 0.850 777280 -53 -35 -28 -20 -13 -8 -2 6 27 35 43 51 57 64 47350 789 317060 87100 87100 142860 0 1682 3.6

106.6 1.8 30000 108.2 0.850 776291 -60 -42 -35 -28 -20 -15 -10 -2 18 27 35 43 49 55 43826 730 316071 87100 87100 141871 0 1405 3.7

107.4 1.8 31000 114.5 0.850 775750 -64 -46 -38 -31 -24 -19 -13 -6 14 23 31 39 45 51 42064 701 315530 87100 87100 141330 0 1248 3.7

127.1 2.1 31000 278.3 0.850 766100 -64 -46 -38 -31 -24 -19 -13 -6 14 23 31 39 45 51 29215 487 305880 87100 87100 131680 0 0 2.2

144.6 2.4 31000 423.6 0.850 757630 -64 -46 -38 -31 -24 -19 -13 -6 14 23 31 39 45 51 28922 482 297410 87100 87100 123210 0 0 2.1

145.4 2.4 32000 430.1 0.850 757092 -67 -49 -42 -35 -27 -22 -17 -10 10 18 27 35 41 47 40074 668 296872 87100 87100 122672 0 1191 3.7

147.4 2.5 34000 446.8 0.850 755805 -74 -56 -49 -42 -35 -29 -24 -19 2 10 19 27 33 39 36700 612 295585 87100 87100 121385 0 843 3.7

148.8 2.5 35000 457.9 0.850 754999 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 35058 584 294779 87100 87100 120579 0 660 3.7

153.8 2.6 35000 499.4 0.850 752602 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 28210 470 292382 87100 87100 118182 0 0 2.9

170.5 2.8 35000 635.1 0.850 744840 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 27855 464 284620 87100 87100 110420 0 0 2.8

187.3 3.1 35000 772.5 0.850 737077 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 27517 459 276857 87100 87100 102657 0 0 2.8

204.3 3.4 35000 911.6 0.850 729315 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 27187 453 269095 87100 87100 94895 0 0 2.7

221.6 3.7 35000 1052.3 0.850 721552 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 26854 448 261332 87100 87100 87132 0 0 2.7

239.0 4.0 35000 1194.8 0.850 713790 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 26527 442 253570 87100 87100 79370 0 0 2.6

256.7 4.3 35000 1339.1 0.850 706027 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 26211 437 245807 87100 87100 71607 0 0 2.6

274.5 4.6 35000 1485.0 0.850 698264 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 25904 432 238044 87100 87100 63844 0 0 2.6

292.6 4.9 35000 1632.7 0.850 690502 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 25609 427 230282 87100 87100 56082 0 0 2.5

310.9 5.2 35000 1782.1 0.850 682739 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 25322 422 222519 87100 87100 48319 0 0 2.5

329.4 5.5 35000 1933.1 0.850 674977 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 25038 417 214757 87100 87100 40557 0 0 2.4

348.1 5.8 35000 2085.8 0.850 667214 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 24762 413 206994 87100 87100 32794 0 0 2.4

367.0 6.1 35000 2240.3 0.850 659452 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 24493 408 199232 87100 87100 25032 0 0 2.3

386.2 6.4 35000 2396.4 0.850 651689 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 24233 404 191469 87100 87100 17269 0 0 2.3

405.5 6.8 35000 2554.2 0.850 643927 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 23985 400 183707 87100 87100 9507 0 0 2.2

425.0 7.1 35000 2713.5 0.850 636164 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 23745 396 175944 87100 87100 1744 0 0 2.2

444.7 7.4 35000 2874.5 0.850 628401 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 23510 392 168181 84091 84091 0 0 0 2.1

464.6 7.7 35000 3037.1 0.850 620639 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 23281 388 160419 80210 80210 0 0 0 2.1

465.0 7.8 35000 3040.5 0.850 620477 -78 -60 -53 -45 -38 -33 -27 -23 -2 6 14 23 29 35 23277 388 160257 80129 80129 0 0 0 2.1

465.7 7.8 36000 3046.3 0.850 620069 -81 -63 -56 -49 -42 -36 -31 -27 -6 2 10 19 25 31 33259 554 159849 79925 79925 0 0 1301 3.8

465.8 7.8 36089 3046.9 0.850 620031 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 33102 552 159811 79906 79906 0 0 1283 3.8

465.8 7.8 36089 3046.9 0.850 620031 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 33102 552 159811 79906 79906 0 0 1159 3.6

467.8 7.8 38000 3063.2 0.850 618978 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 30211 504 158758 79379 79379 0 0 805 3.6

469.2 7.8 39000 3074.8 0.850 618279 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 28807 480 158059 79030 79030 0 0 621 3.6

481.4 8.0 39000 3173.4 0.850 613629 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 22903 382 153409 76705 76705 0 0 0 2.8

494.7 8.2 39000 3282.0 0.850 608550 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 22696 378 148330 74165 74165 0 0 0 2.8

508.2 8.5 39000 3391.6 0.850 603471 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 22491 375 143251 71626 71626 0 0 0 2.8

521.8 8.7 39000 3502.2 0.850 598392 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 22285 371 138172 69086 69086 0 0 0 2.7

535.6 8.9 39000 3613.8 0.850 593313 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 22081 368 133093 66547 66547 0 0 0 2.7

549.4 9.2 39000 3726.5 0.850 588234 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 21879 365 128014 64007 64007 0 0 0 2.6

563.4 9.4 39000 3840.1 0.850 583155 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 21681 361 122935 61468 61468 0 0 0 2.6

577.6 9.6 39000 3954.9 0.850 578077 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 21488 358 117857 58929 58929 0 0 0 2.6

591.8 9.9 39000 4070.6 0.850 572998 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 21299 355 112778 56389 56389 0 0 0 2.5

606.2 10.1 39000 4187.4 0.850 567919 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 21116 352 107699 53850 53850 0 0 0 2.5

620.7 10.3 39000 4305.1 0.850 562840 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20936 349 102620 51310 51310 0 0 0 2.5

635.3 10.6 39000 4423.9 0.850 557761 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20758 346 97541 48771 48771 0 0 0 2.4

650.0 10.8 39000 4543.7 0.850 552682 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20584 343 92462 46231 46231 0 0 0 2.4

664.9 11.1 39000 4664.5 0.850 547603 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20416 340 87383 43692 43692 0 0 0 2.4

679.9 11.3 39000 4786.3 0.850 542525 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20253 338 82305 41153 41153 0 0 0 2.3

695.0 11.6 39000 4909.0 0.850 537446 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 20096 335 77226 38613 38613 0 0 0 2.3

710.2 11.8 39000 5032.7 0.850 532367 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19940 332 72147 36074 36074 0 0 0 2.2

725.5 12.1 39000 5157.4 0.850 527288 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19789 330 67068 33534 33534 0 0 0 2.2

741.0 12.3 39000 5282.9 0.850 522209 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19641 327 61989 30995 30995 0 0 0 2.2

756.6 12.6 39000 5409.5 0.850 517130 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19494 325 56910 28455 28455 0 0 0 2.1

772.3 12.9 39000 5537.0 0.850 512051 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19351 323 51831 25916 25916 0 0 0 2.1

788.1 13.1 39000 5665.4 0.850 506972 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19212 320 46752 23376 23376 0 0 0 2.1

Airplane Standards (3).xls, Profile-large-long 7/8/98
Charts-large-long

Large Airplane

Long Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Altitude (ft)

Pressure Alt

Large Airplane

Long Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Large Airplane

Long Range Mission

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Tail Fuel Remaining

Large Airplane

Long Range Mission

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-large-long 7/8/98
Regional Turbofan Mission

Ground Time (takeoff) = 20 minutes Main 1 Fuel Volume = 1,200 gal Tank Volume = 1,224

Ground Time (landing) = 10 minutes Main 2 Fuel Volume = 1,200 gal Tank Volume = 1,224

^ CWT Fuel Volume = 800 gal Tank Volume = 816

JRS Guess

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0.0 0.000 64270 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 6770 3385 3385 0 0

10.0 0.2 0 0.0 0.000 64270 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 1260 21 6770 3385 3385 0 0

20.0 0.3 0 0.0 0.000 64060 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 9000 150 6560 3280 3280 0 0

21.5 0.4 1500 1.9 0.388 63851 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 7471 125 6351 3176 3176 0 3194

21.6 0.4 2000 2.6 0.391 63832 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 7405 123 6332 3166 3166 0 3166

22.3 0.4 4000 5.4 0.406 63754 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 7143 119 6254 3127 3127 0 3053

22.9 0.4 6000 8.4 0.420 63676 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 6887 115 6176 3088 3088 0 2937

23.6 0.4 8000 11.5 0.436 63598 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 6637 111 6098 3049 3049 0 2817

24.4 0.4 10000 15.0 0.452 63519 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 6386 106 6019 3010 3010 0 2693

25.1 0.4 12000 18.7 0.469 63439 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 6148 102 5939 2970 2970 0 2559

25.9 0.4 14000 22.7 0.487 63359 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 5910 99 5859 2930 2930 0 2422

26.8 0.4 16000 27.1 0.506 63276 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 5678 95 5776 2888 2888 0 2280

27.7 0.5 18000 31.9 0.526 63192 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 5454 91 5692 2846 2846 0 2137

28.6 0.5 20000 37.3 0.547 63106 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 5231 87 5606 2803 2803 0 1994

29.7 0.5 22000 43.2 0.569 63017 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 5012 84 5517 2759 2759 0 1832

30.8 0.5 24000 49.9 0.592 62924 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 4795 80 5424 2712 2712 0 1670

32.1 0.5 26000 57.5 0.616 62825 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 4582 76 5325 2663 2663 0 1503

33.5 0.6 28000 66.4 0.641 62720 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 4375 73 5220 2610 2610 0 1331

35.1 0.6 30000 76.8 0.668 62605 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 4171 70 5105 2553 2553 0 1157

37.0 0.6 32000 89.3 0.696 62478 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 3972 66 4978 2489 2489 0 978

37.2 0.6 32200 90.7 0.699 62464 -68 -50 -43 -35 -28 -23 -17 -30 -10 -2 6 14 20 26 3952 66 4964 2482 2482 0 960

37.3 0.6 32250 91.0 0.700 62461 -68 -50 -43 -36 -28 -23 -18 -30 -10 -2 6 14 20 26 3947 66 4961 2481 2481 0 955

37.9 0.6 33000 95.2 0.700 62421 -71 -53 -45 -38 -31 -26 -20 -33 -13 -5 3 11 17 23 3852 64 4921 2461 2461 0 1205

38.8 0.6 34000 101.0 0.700 62367 -74 -56 -49 -42 -35 -29 -24 -36 -17 -9 -1 7 13 19 3728 62 4867 2434 2434 0 1117

39.7 0.7 35000 107.3 0.700 62309 -78 -60 -53 -45 -38 -33 -27 -40 -21 -13 -5 3 9 15 3604 60 4809 2405 2405 0 1019

45.8 0.8 35000 152.5 0.770 62000 -78 -60 -53 -45 -38 -33 -27 -33 -12 -4 4 12 18 24 3039 51 4500 2250 2250 0 0

55.7 0.9 35000 225.6 0.770 61500 -78 -60 -53 -45 -38 -33 -27 -33 -12 -4 4 12 18 24 3029 50 4000 2000 2000 0 0

65.7 1.1 35000 299.1 0.770 61000 -78 -60 -53 -45 -38 -33 -27 -33 -12 -4 4 12 18 24 3018 50 3500 1750 1750 0 0

73.1 1.2 35000 355.0 0.770 60620 -78 -60 -53 -45 -38 -33 -27 -33 -12 -4 4 12 18 24 3009 50 3120 1560 1560 0 0

74.0 1.2 34000 360.7 0.700 60622 -74 -56 -49 -42 -35 -29 -24 -36 -17 -9 -1 7 13 19 2992 50 3122 1561 1561 0 434

74.3 1.2 33000 362.9 0.700 60620 -71 -53 -45 -38 -31 -26 -20 -33 -13 -5 3 11 17 23 3054 51 3120 1560 1560 0 445

74.6 1.2 32250 364.6 0.700 60618 -68 -50 -43 -36 -28 -23 -18 -30 -10 -2 6 14 20 26 2342 39 3118 1559 1559 0 457

74.6 1.2 32200 364.7 0.699 60618 -68 -50 -43 -35 -28 -23 -17 -30 -10 -2 6 14 20 26 2341 39 3118 1559 1559 0 458

75.1 1.3 31000 368.2 0.682 60614 -64 -46 -38 -31 -24 -19 -13 -27 -7 1 9 17 23 28 2312 39 3114 1557 1557 0 476

75.5 1.3 30000 371.0 0.668 60610 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 2289 38 3110 1555 1555 0 491

76.4 1.3 28000 376.7 0.641 60603 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 2242 37 3103 1552 1552 0 524

77.3 1.3 26000 382.4 0.616 60595 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 2193 37 3095 1548 1548 0 558

78.2 1.3 24000 387.9 0.592 60586 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 2144 36 3086 1543 1543 0 596

79.2 1.3 22000 393.5 0.569 60576 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 2095 35 3076 1538 1538 0 636

80.1 1.3 20000 398.9 0.547 60566 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 2044 34 3066 1533 1533 0 675

81.1 1.4 18000 404.4 0.526 60554 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 1991 33 3054 1527 1527 0 723

82.2 1.4 16000 409.8 0.506 60541 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 1938 32 3041 1521 1521 0 770

83.2 1.4 14000 415.3 0.487 60528 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 1884 31 3028 1514 1514 0 821

84.3 1.4 12000 420.7 0.469 60512 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 1829 30 3012 1506 1506 0 875

85.4 1.4 10000 426.1 0.452 60496 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 1773 30 2996 1498 1498 0 929

86.5 1.4 8000 431.5 0.436 60477 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 1717 29 2977 1489 1489 0 990

87.7 1.5 6000 436.9 0.420 60457 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 1661 28 2957 1479 1479 0 1054

88.9 1.5 4000 442.4 0.406 60435 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 1604 27 2935 1468 1468 0 1124

90.2 1.5 2000 447.9 0.391 60410 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 1544 26 2910 1455 1455 0 1201

90.5 1.5 1500 449.3 0.388 60404 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 1529 25 2904 1452 1452 0 1222

91.5 1.5 0 453.5 0.378 60383 -8 37 57 72 90 100 111 5 52 72 87 105 116 128 1484 25 2883 1442 1442 0 1284

93.5 1.6 0 453.5 0.000 60283 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 3000 50 2783 1392 1392 0 0

103.5 1.7 0 453.5 0.000 60283 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 2783 1392 1392 0 0

Airplane Standards (3).xls, Profile-Reg-Tfan 7/8/98
Large Commercial Transport

Long Range Mission

804.0 13.4 39000 5794.7 0.850 501893 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 19076 318 41673 20837 20837 0 0 0 2.0

813.8 13.6 39000 5874.8 0.850 498769 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 18994 317 38549 19275 19275 0 0 0 2.0

814.2 13.6 38000 5877.4 0.850 498754 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 2980 50 38534 19267 19267 0 0 3149 -1.8

814.6 13.6 36672 5880.7 0.850 498733 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 3087 51 38513 19257 19257 0 0 3242 -2.2

814.6 13.6 36672 5880.7 0.850 498733 -82 -64 -56 -49 -42 -37 -31 -27 -6 2 10 18 24 31 3087 51 38513 19257 19257 0 0 2267 -1.0

814.8 13.6 36089 5882.8 0.840 498719 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17 23 29 3120 52 38499 19250 19250 0 0 2233 -1.0

814.8 13.6 36089 5882.8 0.840 498719 -82 -64 -56 -49 -42 -37 -31 -28 -8 0 9 17 23 29 3120 52 38499 19250 19250 0 0 2391 -1.2

814.9 13.6 36000 5883.1 0.838 498717 -81 -63 -56 -49 -42 -36 -31 -28 -8 1 9 17 23 29 3124 52 38497 19249 19249 0 0 2386 -1.1

815.7 13.6 34000 5889.8 0.805 498672 -74 -56 -49 -42 -35 -29 -24 -24 -4 4 12 20 27 33 3213 54 38452 19226 19226 0 0 2311 -1.0

816.6 13.6 32000 5896.5 0.773 498625 -67 -49 -42 -35 -27 -22 -17 -20 0 8 16 24 30 36 3304 55 38405 19203 19203 0 0 2262 -0.9

817.5 13.6 30000 5903.1 0.742 498575 -60 -42 -35 -28 -20 -15 -10 -16 4 12 20 28 34 40 3407 57 38355 19178 19178 0 0 2217 -0.9

818.4 13.6 28000 5909.7 0.713 498522 -53 -35 -28 -20 -13 -8 -2 -11 8 16 24 32 38 44 3571 60 38302 19151 19151 0 0 2159 -0.8

819.3 13.7 26000 5916.2 0.685 498465 -46 -28 -21 -13 -6 -1 5 -7 13 21 29 37 42 48 3738 62 38245 19123 19123 0 0 2104 -0.8

820.3 13.7 24000 5922.7 0.659 498403 -39 -21 -13 -6 1 6 12 -2 18 25 33 41 47 53 3926 65 38183 19092 19092 0 0 2046 -0.8

821.3 13.7 22000 5929.1 0.634 498336 -31 -13 -6 1 8 14 19 3 22 30 38 46 52 57 4135 69 38116 19058 19058 0 0 1989 -0.8

822.3 13.7 20000 5935.6 0.610 498264 -24 -6 1 8 15 21 26 8 27 35 43 51 56 62 4346 72 38044 19022 19022 0 0 1935 -0.9

823.4 13.7 18000 5942.0 0.587 498187 -23 -2 7 14 23 29 35 7 30 39 47 56 62 69 4542 76 37967 18984 18984 0 0 1896 -0.9

824.4 13.7 16000 5948.4 0.565 498105 -21 2 12 21 30 37 43 7 32 42 51 61 68 75 4749 79 37885 18943 18943 0 0 1862 -1.0

825.5 13.8 14000 5954.6 0.544 498016 -19 7 18 27 38 45 52 7 34 46 56 67 74 82 5023 84 37796 18898 18898 0 0 1823 -1.0

826.6 13.8 12000 5960.9 0.525 497920 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 5359 89 37700 18850 18850 0 0 1776 -1.1

826.6 13.8 12000 5960.9 0.525 497920 -18 11 23 33 45 53 60 7 37 50 61 73 81 89 5359 89 37700 18850 18850 0 0 1237 -0.2

828.5 13.8 10000 5970.3 0.452 497750 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 5704 95 37530 18765 18765 0 0 970 0.4

828.5 13.8 10000 5970.3 0.452 497750 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 5704 95 37530 18765 18765 0 0 1362 -0.3

829.9 13.8 8000 5977.3 0.436 497607 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 5810 97 37387 18694 18694 0 0 1328 -0.4

831.5 13.9 6000 5984.4 0.420 497458 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 5924 99 37238 18619 18619 0 0 1295 -0.5

833.0 13.9 4000 5991.3 0.406 497302 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 6008 100 37082 18541 18541 0 0 1262 -0.6

834.6 13.9 2000 5998.3 0.391 497142 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 6061 101 36922 18461 18461 0 0 1243 -0.7

835.0 13.9 1500 6000.0 0.388 497101 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 6074 101 36881 18441 18441 0 0 1241 -0.7

839.0 14.0 0 6000.0 0.000 496301 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 12000 200 36081 18041 18041 0 0 0

844.0 14.1 0 6000.0 0.000 495801 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 6000 100 35581 17791 17791 0 0 0

869.0 14.5 0 6000.0 0.000 495801 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 35581 17791 17791 0 0 0

Airplane Standards (3).xls, Profile-large-long 7/8/98
Large Commercial Transport

Short Range Mission

339.9 5.7 8000 1977.5 0.436 487152 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 5810 97 26932 13466 13466 0 0 1336 -0.5

341.4 5.7 6000 1984.4 0.420 487003 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 5924 99 26783 13392 13392 0 0 1303 -0.6

342.9 5.7 4000 1991.4 0.406 486849 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 6008 100 26629 13315 13315 0 0 1269 -0.7

344.5 5.7 2000 1998.3 0.391 486689 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 6061 101 26469 13235 13235 0 0 1250 -0.8

344.9 5.7 1500 2000.0 0.388 486648 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 6074 101 26428 13214 13214 0 0 1249 -0.8

348.9 5.8 0 2000.0 0.000 485848 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 12000 200 25628 12814 12814 0 0 0

353.9 5.9 0 2000.0 0.000 485348 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 6000 100 25128 12564 12564 0 0 0

378.9 6.3 0 2000.0 0.000 485348 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 25128 12564 12564 0 0 0

Airplane Standards (3).xls, Profile-large-short 7/8/98
Medium Commercial Transport

Long Range Mission

456.9 7.6 36000 2986.1 0.790 257268 -81 -63 -56 -49 -42 -36 -31 -34 -14 -6 2 10 16 23 13823 230 31890 15945 15945 0 0 1674 4.0

457.0 7.6 36089 2986.5 0.790 257255 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13766 229 31876 15938 15938 0 0 1519 3.9

457.0 7.6 36089 2986.5 0.790 257255 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13766 229 31876 15938 15938 0 0 1519 3.9

457.6 7.6 37000 2991.3 0.790 257111 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 13243 221 31733 15867 15867 0 0 1357 3.8

458.4 7.6 38000 2997.2 0.790 256942 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 12690 211 31563 15782 15782 0 0 1173 3.8

459.4 7.7 39000 3004.4 0.790 256746 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 12039 201 31367 15684 15684 0 0 945 3.7

459.4 7.7 39000 3004.4 0.790 256748 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8790 146 31367 15684 15684 0 0 0 2.5

481.5 8.0 39000 3171.6 0.790 253529 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8653 144 28148 14074 14074 0 0 0 2.5

496.9 8.3 39000 3287.7 0.790 251324 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8565 143 25944 12972 12972 0 0 0 2.5

512.4 8.5 39000 3404.9 0.790 249120 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8477 141 23739 11870 11870 0 0 0 2.4

528.1 8.8 39000 3523.3 0.790 246915 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8391 140 21535 10767 10767 0 0 0 2.4

543.9 9.1 39000 3642.9 0.790 244711 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8316 139 19330 9665 9665 0 0 0 2.3

559.9 9.3 39000 3763.6 0.790 242506 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8243 137 17125 8563 8563 0 0 0 2.3

573.3 9.6 39000 3864.4 0.790 240678 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 8181 136 15298 7649 7649 0 0 0 2.3

573.3 9.6 39000 3864.4 0.790 240678 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 2088 35 15298 7649 7649 0 0 -2344 -0.6

573.7 9.6 38035 3867.5 0.790 240665 -82 -64 -56 -49 -42 -37 -31 -34 -14 -6 2 10 16 22 2103 35 15284 7642 7642 0 0 -1709 0.0

574.3 9.6 37000 3872.0 0.773 240643 -82 -64 -56 -49 -42 -37 -31 -37 -16 -8 0 8 14 20 2061 34 15262 7631 7631 0 0 -1689 0.0

574.8 9.6 36089 3876.0 0.758 240623 -82 -64 -56 -49 -42 -37 -31 -38 -18 -10 -2 6 12 18 1993 33 15243 7621 7621 0 0 -1786 -0.1

575.4 9.6 35000 3880.4 0.741 240603 -78 -60 -53 -45 -38 -33 -27 -36 -16 -8 0 8 14 20 1916 32 15223 7611 7611 0 0 -1785 -0.1

576.0 9.6 34000 3884.3 0.726 240586 -74 -56 -49 -42 -35 -29 -24 -34 -14 -6 2 10 16 22 1836 31 15205 7603 7603 0 0 -1791 -0.1

576.5 9.6 33000 3888.2 0.711 240568 -71 -53 -45 -38 -31 -26 -20 -31 -12 -4 4 12 18 24 1750 29 15187 7594 7594 0 0 -1805 -0.1

577.1 9.6 32000 3891.9 0.696 240553 -67 -49 -42 -35 -27 -22 -17 -29 -9 -1 6 14 20 26 1656 28 15172 7586 7586 0 0 -1825 -0.1

577.6 9.6 31000 3895.6 0.682 240537 -64 -46 -38 -31 -24 -19 -13 -27 -7 1 9 17 23 28 1675 28 15157 7578 7578 0 0 -1810 -0.2

578.2 9.6 30000 3899.3 0.668 240522 -60 -42 -35 -28 -20 -15 -10 -24 -5 3 11 19 25 31 1698 28 15141 7571 7571 0 0 -1795 -0.1

578.8 9.6 29000 3902.9 0.655 240506 -56 -38 -31 -24 -17 -11 -6 -22 -2 6 13 21 27 33 1709 28 15126 7563 7563 0 0 -1785 -0.1

579.3 9.7 28000 3906.5 0.641 240491 -53 -35 -28 -20 -13 -8 -2 -19 0 8 16 23 29 35 1709 28 15110 7555 7555 0 0 -1777 -0.1

579.9 9.7 27000 3910.1 0.628 240476 -49 -31 -24 -17 -10 -4 1 -17 3 10 18 26 32 37 1746 29 15095 7547 7547 0 0 -1757 -0.2

580.5 9.7 26000 3913.6 0.616 240458 -46 -28 -21 -13 -6 -1 5 -14 5 13 21 28 34 40 1786 30 15077 7539 7539 0 0 -1738 -0.2

581.0 9.7 25000 3917.2 0.604 240440 -42 -24 -17 -10 -3 3 8 -12 8 15 23 31 37 42 1823 30 15060 7530 7530 0 0 -1720 -0.1

581.6 9.7 24000 3920.7 0.592 240423 -39 -21 -13 -6 1 6 12 -9 10 18 26 33 39 45 1861 31 15042 7521 7521 0 0 -1702 -0.1

582.2 9.7 23000 3924.2 0.580 240405 -35 -17 -10 -3 5 10 15 -6 13 20 28 36 42 47 1896 32 15024 7512 7512 0 0 -1685 -0.1

582.8 9.7 22000 3927.6 0.569 240385 -31 -13 -6 1 8 14 19 -4 15 23 31 38 44 50 1922 32 15005 7502 7502 0 0 -1672 -0.1

583.4 9.7 21000 3931.1 0.558 240368 -28 -10 -3 5 12 17 23 -1 18 26 33 41 47 53 1940 32 14987 7493 7493 0 0 -1661 -0.2

584.0 9.7 20000 3934.5 0.547 240348 -24 -6 1 8 15 21 26 2 21 28 36 44 49 55 1951 33 14967 7484 7484 0 0 -1653 -0.2

584.6 9.7 19000 3937.8 0.536 240328 -23 -4 4 11 19 25 30 2 22 30 38 47 53 59 2006 33 14947 7474 7474 0 0 -1633 -0.2

585.2 9.8 18000 3941.2 0.526 240308 -23 -2 7 14 23 29 35 2 23 32 41 49 56 62 2059 34 14927 7464 7464 0 0 -1615 -0.2

585.9 9.8 17000 3944.6 0.516 240286 -22 0 9 18 26 33 39 2 25 34 43 52 59 65 2110 35 14905 7453 7453 0 0 -1598 -0.2

586.5 9.8 16000 3947.9 0.506 240264 -21 2 12 21 30 37 43 2 26 36 45 55 62 69 2154 36 14883 7442 7442 0 0 -1584 -0.2

587.1 9.8 15000 3951.2 0.497 240242 -20 5 15 24 34 41 47 2 28 38 48 58 65 72 2202 37 14861 7431 7431 0 0 -1568 -0.3

587.8 9.8 14000 3954.5 0.487 240218 -19 7 18 27 38 45 52 2 29 40 50 61 69 76 2251 38 14837 7418 7418 0 0 -1552 -0.3

588.4 9.8 13000 3957.8 0.478 240193 -18 9 21 30 41 49 56 2 30 43 53 64 72 79 2295 38 14813 7406 7406 0 0 -1537 -0.3

589.1 9.8 12000 3961.0 0.469 240169 -18 11 23 33 45 53 60 2 32 45 55 67 75 83 2337 39 14788 7394 7394 0 0 -1524 -0.3

589.7 9.8 11000 3964.3 0.461 240143 -17 13 26 37 49 57 64 2 33 47 58 70 79 87 2372 40 14762 7381 7381 0 0 -1513 -0.3

590.4 9.8 10000 3967.5 0.452 240118 -16 16 29 40 52 61 69 2 35 49 60 73 82 90 2394 40 14738 7369 7369 0 0 -1506 -0.4

591.0 9.9 9000 3970.6 0.444 240092 -15 18 32 43 56 65 73 2 37 51 63 77 85 94 2394 40 14711 7356 7356 0 0 -1507 -0.4

591.7 9.9 8000 3973.8 0.436 240063 -14 20 35 46 60 69 77 3 38 53 65 80 89 98 2392 40 14685 7342 7342 0 0 -1508 -0.4

592.4 9.9 7000 3976.9 0.428 240039 -13 22 37 49 64 73 81 3 40 56 68 83 92 101 2429 40 14658 7329 7329 0 0 -1497 -0.5

593.0 9.9 6000 3979.9 0.420 240010 -13 24 40 53 67 76 86 3 41 58 71 86 95 105 2478 41 14630 7315 7315 0 0 -1482 -0.5

593.7 9.9 5000 3983.0 0.413 239984 -12 26 43 56 71 80 90 4 43 60 73 89 99 109 2524 42 14603 7302 7302 0 0 -1469 -0.5

594.4 9.9 4000 3986.0 0.406 239955 -11 29 46 59 75 84 94 4 45 63 76 92 102 112 2568 43 14575 7287 7287 0 0 -1456 -0.5

595.1 9.9 3000 3989.0 0.398 239924 -10 31 49 62 78 88 98 4 46 65 79 96 106 116 2621 44 14544 7272 7272 0 0 -1443 -0.5

595.8 9.9 2000 3992.0 0.391 239896 -9 33 52 65 82 92 103 5 48 67 81 99 109 120 2670 44 14515 7258 7258 0 0 -1429 -0.5

596.1 9.9 1500 3993.5 0.388 239878 -9 34 53 67 84 94 105 5 49 68 83 100 111 122 2692 45 14497 7249 7249 0 0 -1422 -0.6

599.8 10.0 0 3993.5 0.000 239541 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 14160 7080 7080 0 0 0 0.0

629.8 10.5 0 3993.5 0.000 239541 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 14160 7080 7080 0 0 0 0.0

Airplane Standards (3).xls, Profile-med-long 7/8/98
Charts-Reg-Tfan

Regional Turbofan

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 1 2

Time (hr)

Altitude (ft)

Pressure Alt

Regional Turbofan

-100

-50

0

50

100

150

0 1 2

Time (hr)

Ambient Temp (F)

-8

37

57

72

90

100

111

Regional Turbofan

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

0 1 2

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Regional Turbofan

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-Reg-Tfan 7/8/98
Regional Turboprop Mission

Ground Time (takeoff) = 20 minutes Main 1 Fuel Volume = 700 gal Tank Volume = 714

Ground Time (landing) = 10 minutes Main 2 Fuel Volume = 700 gal Tank Volume = 714

^ CWT Fuel Volume = 0 gal Tank Volume = 0

JRS Guess

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0.0 0.000 41100 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 5764 2882 2882 0 0

10.0 0.2 0 0.0 0.000 41100 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 5764 2882 2882 0 0

20.0 0.3 0 0.0 0.000 41100 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 5764 2882 2882 0 0

23.0 0.4 2000 8.0 0.297 41023 -9 33 52 65 82 92 103 -1 42 61 75 92 102 113 1784 30 5687 2843 2843 0 667

25.0 0.4 4000 16.0 0.299 40952 -11 29 46 59 75 84 94 -3 37 55 68 84 94 104 1744 29 5616 2808 2808 0 800

28.0 0.5 6000 25.0 0.301 40880 -13 24 40 53 67 76 86 -5 33 49 62 77 86 96 1712 29 5544 2772 2772 0 750

31.0 0.5 8000 36.0 0.303 40802 -14 20 35 46 60 69 77 -6 29 44 56 69 78 87 1682 28 5466 2733 2733 0 727

34.0 0.6 10000 47.0 0.306 40721 -16 16 29 40 52 61 69 -8 24 38 49 62 70 79 1658 28 5385 2692 2692 0 714

37.0 0.6 12000 58.0 0.295 40637 -18 11 23 33 45 53 60 -10 19 32 42 54 62 69 1640 27 5301 2651 2651 0 706

39.0 0.7 14000 65.0 0.285 40575 -19 7 18 27 38 45 52 -12 14 26 35 46 53 60 1636 27 5239 2620 2620 0 737

41.0 0.7 16000 75.0 0.274 40516 -21 2 12 21 30 37 43 -14 9 19 28 38 44 51 1540 26 5180 2590 2590 0 762

43.0 0.7 18000 85.0 0.263 40450 -23 -2 7 14 23 29 35 -17 4 13 21 29 35 41 1446 24 5114 2557 2557 0 783

47.0 0.8 20000 95.0 0.252 40383 -24 -6 1 8 15 21 26 -19 -1 7 14 21 27 32 1356 23 5047 2524 2524 0 741

50.0 0.8 20000 108.6 0.441 40316 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4980 2490 2490 0 0

53.0 0.9 20000 122.1 0.441 40248 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4912 2456 2456 0 0

56.0 0.9 20000 135.7 0.441 40180 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4844 2422 2422 0 0

59.0 1.0 20000 149.2 0.441 40112 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4776 2388 2388 0 0

62.0 1.0 20000 162.8 0.441 40045 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4709 2354 2354 0 0

65.0 1.1 20000 176.3 0.441 39977 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4641 2320 2320 0 0

68.0 1.1 20000 189.9 0.441 39909 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4573 2287 2287 0 0

70.0 1.2 20000 198.9 0.441 39864 -24 -6 1 8 15 21 26 -7 11 19 26 34 39 45 1356 23 4528 2264 2264 0 0

74.0 1.2 20000 215.9 0.366 39766 -24 -6 1 8 15 21 26 -13 6 13 21 28 34 39 1356 23 4430 2215 2215 0 1250

78.0 1.3 18000 235.9 0.363 39676 -23 -2 7 14 23 29 35 -11 10 19 27 35 42 48 1350 23 4340 2170 2170 0 1500

79.0 1.3 16000 241.9 0.361 39661 -21 2 12 21 30 37 43 -10 14 24 33 43 50 56 900 15 4325 2163 2163 0 2000

80.0 1.3 14000 246.9 0.358 39646 -19 7 18 27 38 45 52 -8 19 30 40 50 58 65 900 15 4310 2155 2155 0 2000

81.0 1.4 12000 251.9 0.355 39631 -18 11 23 33 45 53 60 -6 23 36 46 58 66 73 900 15 4295 2148 2148 0 2000

82.0 1.4 10000 255.9 0.353 39616 -16 16 29 40 52 61 69 -5 27 41 52 65 73 82 900 15 4280 2140 2140 0 2000

83.0 1.4 8000 260.9 0.350 39606 -14 20 35 46 60 69 77 -3 32 47 59 73 81 90 600 10 4270 2135 2135 0 2000

84.0 1.4 6000 264.9 0.347 39596 -13 24 40 53 67 76 86 -2 36 52 65 80 89 99 600 10 4260 2130 2130 0 2000

85.0 1.4 4000 268.9 0.345 39586 -11 29 46 59 75 84 94 0 40 58 71 87 97 107 600 10 4250 2125 2125 0 2000

86.0 1.4 2000 273.9 0.343 39576 -9 33 52 65 82 92 103 1 45 64 78 95 105 116 600 10 4240 2120 2120 0 2000

87.0 1.5 0 278.9 0.000 39566 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 4230 2115 2115 0 0

97.0 1.6 0 278.9 0.000 39566 -8 37 57 72 90 100 111 -8 37 57 72 90 100 111 0 0 4230 2115 2115 0 0

Airplane Standards (3).xls, Profile-Reg-Tprop 7/8/98
Charts-Reg-Tprop

Regional Turboprop

0

5,000

10,000

15,000

20,000

25,000

0 1 2

Time (hr)

Altitude (ft)

Pressure Alt

Regional Turboprop

-40

-20

0

20

40

60

80

100

120

0 1 2

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Regional Turboprop

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

0 1 2

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Regional Turboprop

-40

-20

0

20

40

60

80

100

120

140

0 1 2

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-Reg-Tprop 7/8/98
Bizjet

Short Range Mission

Ground Time (takeoff) = 20 minutes Main 1 Fuel Volume = 3075 gal Tank Volume = 3136.5

Ground Time (landing) = 10 minutes Main 2 Fuel Volume = 3075 gal Tank Volume = 3136.5

^ CWT Fuel Volume = 0 gal Tank Volume = 0

JRS Guess

Time Time Pressure 

Alt Dist Mach 

Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel 

Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs

Very 

Cold 1% Cool 25% Average 

50% Warm 75% Hot 95% Very 

Hot 99%

Extreme

ly Hot 

99.9%

Very Cold 

1% Cool 25% Average 

50% Warm 75% Hot 95% Very Hot 

99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0.0 0.000 58385 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 8785 4393 4393 0 0

10.0 0.2 0 0.0 0.000 58385 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 1200 20 8785 4393 4393 0 0

20.0 0.3 0 0.0 0.000 58185 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 12000 200 8585 4293 4293 0 0

21.0 0.4 1500 0.0 0.380 57985 -9 34 53 67 84 94 105 4.17 48.38 67.78 82.04 99.73 110.42 121.12 12000 200 8385 4193 4193 0 3000

33.0 0.6 41000 72.0 0.800 56720 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 6325 105 7120 3560 3560 0 3000

34.0 0.6 43000 80.0 0.800 56650 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 4200 70 7050 3525 3525 0 2000

35.0 0.6 45000 90.0 0.800 56574 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 4560 76 6974 3487 3487 0 1300

37.0 0.6 47000 103.0 0.800 56486 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2640 44 6886 3443 3443 0 800

40.0 0.7 49000 122.0 0.800 56371 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2300 38 6771 3386 3386 0 700

91.0 1.5 49000 513.0 0.800 54571 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2118 35 4971 2486 2486 0 0

95.0 1.6 51000 542.0 0.800 54413 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2370 40 4813 2407 2407 0 500

137.0 2.3 51000 864.0 0.800 52976 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2053 34 3376 1688 1688 0 0

160.0 2.7 50 1002.0 0.180 52633 -8 37 57 71 89 100 111 -4.71 40.51 60.41 74.88 92.97 103.83 114.69 895 15 3033 1517 1517 0 -2000

165.0 2.8 0 1002.0 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 2208 37 2849 1425 1425 0 0

175.0 2.9 0 1002.0 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 2849 1425 1425 0 0

Airplane Standards (3).xls, Profile-bizjet-short 7/8/98
Charts-bizjet-short

Bizjet

Short Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Short Range Mission

-100

-50

0

50

100

150

0 1 2 3 4

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Bizjet

Short Range Mission

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

0 1 2 3 4

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Short Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-bizjet-short 7/8/98
Bizjet

Medium Range Mission

Ground Time (takeoff) = 20 minutes Main 1 Fuel Volume = 3075 gal Tank Volume = 3136.5

Ground Time (landing) = 10 minutes Main 2 Fuel Volume = 3075 gal Tank Volume = 3136.5

^ CWT Fuel Volume = N/A gal Tank Volume = #VALUE!

JRS Guess

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Very Hot 

99%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0.0 0.000 68689 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 19089 9545 9545 0

10.0 0.2 0 0.0 0.000 68689 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 1200 20 19089 9545 9545 0

20.0 0.3 0 0.0 0.000 68489 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 12000 200 18889 9445 9445 0

21.0 0.4 1500 0.0 0.380 68289 -9 34 53 67 84 94 105 4.17 48.38 67.78 82.04 99.73 110.42 121.12 6224 104 18689 9345 9345 0 2600

36.0 0.6 41000 90.0 0.800 66733 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2910 49 17133 8567 8567 0 2600

38.0 0.6 43000 101.0 0.800 66636 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3390 57 17036 8518 8518 0 1000

40.0 0.7 45000 115.0 0.800 66523 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3120 52 16923 8462 8462 0 800

43.0 0.7 47000 137.0 0.800 66367 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2376 40 16767 8384 8384 0 700

192.0 3.2 47000 1276.0 0.800 60467 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2385 40 10867 5434 5434 0 0

196.0 3.3 49000 1302.0 0.800 60308 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2175 36 10708 5354 5354 0 500

356.0 5.9 49000 2527.0 0.800 54508 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2355 39 4908 2454 2454 0 0

360.0 6.0 51000 2556.0 0.800 54351 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2063 34 4751 2376 2376 0 500

400.0 6.7 51000 2864.0 0.800 52976 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 895 15 3376 1688 1688 0 0

423.0 7.1 50 3002.0 0.180 52633 -8 37 57 71 89 100 111 -4.71 40.51 60.41 74.88 92.97 103.83 114.69 2208 37 3033 1517 1517 0 -2000

428.0 7.1 0 3002.0 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 2849 1425 1425 0 0

438.0 7.3 0 3002.0 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 2849 1425 1425 0 0

Airplane Standards (3).xls, Profile-bizjet-med 7/8/98
Charts-bizjet-med

Bizjet

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7 8

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Very Hot 99%

Bizjet

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

0 1 2 3 4 5 6 7 8

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-bizjet-med 7/8/98
Bizjet

Long Range Mission

Ground Time (takeoff) = 20 minutes Main 1 Fuel Volume = 3075 gal Tank Volume = 3136.5

Ground Time (landing) = 10 minutes Main 2 Fuel Volume = 3075 gal Tank Volume = 3136.5

^ CWT Fuel Volume = N/A gal Tank Volume = #VALUE!

JRS Guess

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temperatures (Degrees F) Total Temperatures (Degrees F) Fuel Flow

Fuel 

Flow

Fuel 

Remainin

g

Main 

Tank 1 

Fuel 

Remainin

g

Main 

Tank 2 

Fuel 

Remainin

g

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Very Hot 

99%

Very Cold 

1% Cool 25% Average 50% Warm 75% Hot 95% Very Hot 99%

Extremely 

Hot 99.9% lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0 0.000 90900 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 41300 20603 20603 95 0

10.0 0.2 0 0 0.000 90900 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 1200 20 41300 20603 20603 95 0

20.0 0.3 0 0 0.000 90700 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 12000 200 41100 20550 20550 0 0

21.0 0.4 1500 0 0.380 90500 -9 34 53 67 84 94 105 4.17 48.38 67.78 82.04 99.73 110.42 121.12 6237 104 40900 20450 20450 0 1550

44.0 0.7 41000 145 0.800 88109 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3106 52 38509 19255 19255 0 1550

185.0 3.1 41000 1226 0.800 80809 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3620 60 31209 15605 15605 0 0

188.0 3.1 43000 1247 0.800 80628 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2840 47 31028 15514 15514 0 1500

338.0 5.6 43000 2392 0.800 73528 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3280 55 23928 11964 11964 0 0

341.0 5.7 45000 2413 0.800 73364 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2594 43 23764 11882 11882 0 1500

496.0 8.3 45000 3595 0.800 66664 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 3160 53 17064 8532 8532 0 0

499.0 8.3 47000 3618 0.800 66506 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2377 40 16906 8453 8453 0 1500

653.0 10.9 47000 4795 0.800 60406 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2370 40 10806 5403 5403 0 0

657.0 11.0 49000 4820 0.800 60248 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2178 36 10648 5324 5324 0 1000

814.0 13.6 49000 6024 0.800 54548 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2370 40 4948 2474 2474 0 0

818.0 13.6 51000 6053 0.800 54390 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 2020 34 4790 2395 2395 0 1000

860.0 14.3 51000 6370 0.800 52976 -82 -64 -56 -49 -42 -37 -31 -33.30 -12.99 -4.87 3.25 11.37 17.46 23.55 895 15 3376 1688 1688 0 0

883.0 14.7 50 6508 0.180 52633 -8 37 57 71 89 100 111 -4.71 40.51 60.41 74.88 92.97 103.83 114.69 2208 37 3033 1517 1517 0 -2000

888.0 14.8 0 6508 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 2849 1425 1425 0 0

898.0 15.0 0 6508 0.000 52449 -8 37 57 72 90 100 111 -7.60 37.40 57.20 71.60 89.60 100.40 111.20 0 0 2849 1425 1425 0 0

Airplane Standards (3).xls, Profile-bizjet-long 7/8/98
Charts-bizjet-long

Bizjet

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Very Hot 99%

Bizjet

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-bizjet-long 7/8/98
climb

SMALL AIRPLANE

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 110211 4525 0.388 16119

2000 2000 0.0019 0.5 110181 4482 0.3914 15950

4000 4000 0.0094 2.4 110063 4309 0.4056 15290

6000 6000 0.0173 4.5 109945 4135 0.4204 14649

8000 8000 0.0256 6.8 109826 3950 0.436 14004

10000 10000 0.0342 9.2 109708 3753 0.4523 13350

10000 10000 0.0342 9.2 109708 500 0.4523 13350

10126 10126 0.0384 10.5 109651 500 0.5068 13555

10126 10126 0.0384 10.5 109651 3783 0.5068 13553

12000 12000 0.0469 13.3 109539 3577 0.5245 12980

14000 14000 0.0566 16.5 109417 3355 0.5443 12377

16000 16000 0.0669 20.1 109293 3125 0.5651 11750

18000 18000 0.078 24 109166 2889 0.5869 11125

20000 20000 0.09 28.5 109036 2658 0.6098 10562

22000 22000 0.1031 33.4 108900 2438 0.6338 10082

24000 24000 0.1175 39.1 108759 2217 0.6589 9600

26000 26000 0.1334 45.5 108611 1986 0.6853 9125

28000 28000 0.1513 53 108451 1752 0.7131 8679

29855 29855 0.1702 61.1 108291 1531 0.74 8289

29855 29855 0.1702 61.1 108291 2091 0.74 8289

30000 30000 0.1714 61.6 108282 2072 0.74 8248

32000 32000 0.1886 69.1 108144 1806 0.74 7682

34000 34000 0.2088 77.8 107995 1521 0.74 7134

35000 35000 0.2204 82.7 107914 1373 0.74 6868

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 116192 4236 0.388 16119

2000 2000 0.002 0.5 116160 4195 0.3914 15950

4000 4000 0.0101 2.6 116033 4029 0.4056 15290

6000 6000 0.0185 4.8 115907 3863 0.4204 14649

8000 8000 0.0274 7.3 115780 3686 0.436 14004

10000 10000 0.0367 9.9 115653 3498 0.4523 13350

10000 10000 0.0367 9.9 115653 500 0.4523 13350

10137 10137 0.0412 11.3 115592 500 0.5069 13551

10137 10137 0.0412 11.3 115592 3536 0.5069 13550

12000 12000 0.0503 14.2 115472 3341 0.5245 12980

14000 14000 0.0606 17.7 115342 3129 0.5443 12377

16000 16000 0.0716 21.5 115208 2910 0.5651 11750

18000 18000 0.0836 25.8 115072 2685 0.5869 11125

20000 20000 0.0965 30.6 114932 2463 0.6098 10562

22000 22000 0.1107 35.9 114786 2253 0.6338 10082

Page 1
cruise

SMALL AIRPLANE

ENROUTECRUISE ANALYSIS 35000 0 (FEET)

WIND (KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCETIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

107914 0 0 0 0.09151 429.432 4692.7 0.745

107029 81.3 0.1893 886 0.09205 429.432 4665.4 0.745

105970 179 0.4169 1944 0.09268 429.432 4633.4 0.745

104912 277.5 0.6462 3003 0.09332 429.406 4601.6 0.74496

104523 313.9 0.7309 3392 0.09355 429.395 4590.1 0.74494

ENROUTECRUISE ANALYSIS 35000 0 (FEET)

WIND (KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCETIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

113693 0 0 0 0.08792 429.432 4884.4 0.745

113379 27.6 0.0642 313 0.08812 429.432 4873.3 0.745

112321 121.2 0.2822 1372 0.08879 429.432 4836.6 0.745

111263 215.5 0.5019 2430 0.08945 429.432 4800.7 0.745

110204 310.6 0.7232 3489 0.09011 429.432 4765.7 0.745

109146 406.3 0.9461 4547 0.09076 429.432 4731.5 0.745

108087 502.7 1.1706 5606 0.09141 429.432 4698.1 0.745

107029 599.8 1.3967 6664 0.09205 429.432 4665.4 0.745

105970 697.5 1.6243 7722 0.09268 429.432 4633.4 0.745

104912 796 1.8535 8781 0.09332 429.406 4601.6 0.74496

104808 805.7 1.8761 8885 0.09338 429.403 4598.5 0.74495

ENROUTECRUISE ANALYSIS 31000 0 (FEET)

WIND (KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCETIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

126532 0 0 0 0.07859 437.114 5562.2 0.74496

125495 81.7 0.187 1037 0.07903 437.088 5530.8 0.74491

Page 1
descent

SMALL AIRPLANE

ENROUTE DESC ENT ANALYSIS

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

35000 35000 0.3078 99.9 104523 400 3096 0.74 760

34923 34923 0.3074 99.7 104522 400 3101 0.74 760

34923 34923 0.3074 99.7 104522 400 2274 0.74 760

34000 34000 0.3005 96.9 104517 395 2239 0.7258 760

32000 32000 0.2855 90.6 104506 383 2195 0.6962 775

30000 30000 0.2701 84.5 104493 371 2143 0.6681 820

28000 28000 0.2544 78.4 104480 358 2091 0.6414 877

26000 26000 0.2382 72.4 104465 343 2039 0.6159 933

24000 24000 0.2217 66.4 104449 327 1989 0.5917 996

22000 22000 0.2047 60.4 104432 309 1941 0.5687 1062

20000 20000 0.1873 54.5 104413 290 1894 0.5469 1132

18000 18000 0.1695 48.6 104392 270 1843 0.526 1206

16000 16000 0.1512 42.7 104369 247 1792 0.5062 1283

14000 14000 0.1323 36.8 104344 222 1741 0.4874 1365

12000 12000 0.1129 31 104317 194 1691 0.4694 1450

10000 10000 0.0928 25.1 104287 164 1640 0.4523 1540

8000 8000 0.0722 19.3 104254 132 1591 0.436 1633

6000 6000 0.0509 13.4 104218 96 1541 0.4204 1732

4000 4000 0.0289 7.5 104179 56 1483 0.4056 1853

2000 2000 0.0059 1.5 104134 12 1421 0.3914 2004

1500 1500 0 0 104122 0 1405 0.388 2045

ENROUTE DESC ENT ANALYSIS

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

35000 35000 0.3081 100 104808 401 3094 0.74 760

34923 34923 0.3076 99.8 104808 400 3099 0.74 760

34923 34923 0.3076 99.8 104808 400 2272 0.74 760

34000 34000 0.3008 96.9 104802 395 2237 0.7258 760

32000 32000 0.2858 90.7 104791 383 2193 0.6962 775

30000 30000 0.2704 84.6 104779 371 2142 0.6681 820

28000 28000 0.2546 78.5 104765 358 2089 0.6414 877

26000 26000 0.2385 72.4 104751 343 2037 0.6159 933

24000 24000 0.2219 66.4 104735 327 1987 0.5917 996

Page 1
med-short-data

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A B C D E F G H I J K L M N O P Q

A310-308 1000NM ISA conditions

Fuel Distribution

ALT. A/C WT MACH TIME FUEL DIST RATE GRDT ALPH WFE Loutr Linr Ctr Trim Rinr Routr FOB

( FT ) ( KG ) ( ) ( MN ) ( KG ) ( NM ) (FTMN) (DEG.) (DEG.) (KG/H) (kg) (kg) (kg) (kg) (kg) (kg) (kg)

0 117684 0 0 0 0 0 0 0 3000 4726 0 0 4726 3000 15452

116559 0 45 1125 0 0 0 0 1500 3000 4163.5 0 0 4163.5 3000 14327

1500 116223 0.388 46.51 1462 3 4356.8 9.7 2.78 13291 3000 3995 0 0 3995 3000 13990

2000 116198 0.391 46.62 1487 3.5 4371.6 9.66 2.78 13286 3000 3982.5 0 0 3982.5 3000 13965

3000 116147 0.398 46.85 1538 4.5 4410.8 9.61 2.79 13301 3000 3957 0 0 3957 3000 13914

4000 116097 0.406 47.07 1588 5.4 4436.9 9.53 2.79 13272 3000 3932 0 0 3932 3000 13864

5000 116048 0.413 47.3 1637 6.4 4518.5 9.57 2.79 13362 3000 3907.5 0 0 3907.5 3000 13815

6000 115999 0.42 47.52 1686 7.4 4545.6 9.49 2.78 13329 3000 3883 0 0 3883 3000 13766

7000 115950 0.428 47.74 1735 8.4 4496.8 9.25 2.79 13153 3000 3858.5 0 0 3858.5 3000 13717

8000 115901 0.436 47.96 1784 9.4 4434.7 8.99 2.79 12967 3000 3834 0 0 3834 3000 13668

9000 115852 0.444 48.19 1833 10.5 4395.6 8.78 2.79 12840 3000 3809.5 0 0 3809.5 3000 13619

10000 115804 0.452 48.42 1881 11.6 4348.8 8.55 2.79 12695 3000 3785.5 0 0 3785.5 3000 13571

10000 115736 0.541 48.74 1949 13.2 4436.7 7.29 1.27 12907 3000 3751.5 0 0 3751.5 3000 13503

11000 115687 0.551 48.96 1998 14.6 4328.1 7.01 1.26 12644 3000 3727 0 0 3727 3000 13454

12000 115638 0.561 49.2 2047 15.9 4211 6.72 1.26 12373 3000 3702.5 0 0 3702.5 3000 13405

13000 115589 0.571 49.44 2096 17.4 4088.5 6.43 1.26 12094 3000 3678 0 0 3678 3000 13356

14000 115540 0.582 49.69 2145 18.8 3961.9 6.14 1.26 11819 3000 3653.5 0 0 3653.5 3000 13307

15000 115490 0.593 49.95 2195 20.4 3832.4 5.85 1.26 11552 3000 3628.5 0 0 3628.5 3000 13257

16000 115439 0.604 50.21 2246 22.1 3721.6 5.59 1.25 11332 3000 3603 0 0 3603 3000 13206

17000 115388 0.615 50.48 2297 23.8 3603.9 5.34 1.24 11097 3000 3577.5 0 0 3577.5 3000 13155

18000 115337 0.627 50.77 2348 25.6 3475.7 5.07 1.23 10842 3000 3552 0 0 3552 3000 13104

19000 115284 0.639 51.06 2401 27.5 3338.2 4.8 1.21 10570 3000 3525.5 0 0 3525.5 3000 13051

20000 115231 0.651 51.37 2454 29.5 3191.6 4.52 1.2 10284 3000 3499 0 0 3499 3000 12998

21000 115177 0.664 51.68 2508 31.6 3092.6 4.31 1.19 10115 3000 3472 0 0 3472 3000 12944

22000 115122 0.677 52.01 2563 33.9 2980 4.09 1.17 9913 3000 944.5 0 5000 944.5 3000 12889

23000 115066 0.69 52.36 2619 36.3 2855.3 3.86 1.16 9681 3000 916.5 0 5000 916.5 3000 12833

24000 115009 0.703 52.71 2676 38.8 2719.4 3.62 1.15 9422 3000 888 0 5000 888 3000 12776

25000 114950 0.717 53.09 2735 41.5 2575 3.38 1.12 9141 3000 858.5 0 5000 858.5 3000 12717

26000 114890 0.731 53.49 2795 44.3 2457.2 3.17 1.09 8936 3000 828.5 0 5000 828.5 3000 12657

27000 114829 0.745 53.91 2856 47.4 2331.4 2.97 1.06 8718 3000 798 0 5000 798 3000 12596

28000 114766 0.76 54.35 2919 50.7 2201.6 2.76 1.02 8489 3000 766.5 0 5000 766.5 3000 12533

29000 114700 0.775 54.82 2985 54.3 2070.5 2.55 0.97 8248 3000 733.5 0 5000 733.5 3000 12467

29959 114635 0.79 55.3 3050 57.9 1928.8 2.34 0.92 8009 3000 701 0 5000 701 3000 12402

29959 114635 0.79 55.3 3050 57.9 2728.3 3.32 0.92 8009 3000 701 0 5000 701 3000 12402

30000 114633 0.79 55.31 3052 58.1 2724.2 3.31 0.93 7999 3000 700 0 5000 700 3000 12400

31000 114584 0.79 55.69 3101 61 2579.3 3.15 1.06 7690 3000 675.5 0 5000 675.5 3000 12351

32000 114534 0.79 56.09 3151 64 2429.2 2.98 1.2 7387 3000 650.5 0 5000 650.5 3000 12301

33000 114483 0.79 56.51 3202 67.3 2279.3 2.81 1.35 7114 3000 625 0 5000 625 3000 12250

34000 114430 0.79 56.97 3255 70.8 2118.6 2.62 1.51 6842 3000 598.5 0 5000 598.5 3000 12197

35000 114375 0.79 57.46 3310 74.5 1951.1 2.42 1.68 6574 3000 571 0 5000 571 3000 12142

36000 114317 0.79 58 3368 78.6 1758.6 2.2 1.86 6270 3000 542 0 5000 542 3000 12084

36089 114312 0.79 58.05 3373 79 1596.4 1.99 1.87 6244 3000 539.5 0 5000 539.5 3000 12079

36089 114312 0.79 58.05 3373 79 1596.4 1.99 1.87 6244 3000 539.5 0 5000 539.5 3000 12079

37000 114250 0.79 58.65 3435 83.5 1437.9 1.8 2.04 6007 3000 508.5 0 5000 508.5 3000 12017

38000 114177 0.79 59.39 3508 89.1 1255.4 1.57 2.24 5756 3000 472 0 5000 472 3000 11944

39000 114096 0.79 60.27 3589 95.7 1035.6 1.29 2.44 5461 3000 431.5 0 5000 431.5 3000 11863

39000 114095 0.79 60.27 3589 95.7 0 0 2.45 3889 3000 431.5 0 5000 431.5 3000 11863

39000 113000 0.79 77.26 4684 224 0 0 2.41 3845 3000 431.5 3905 0 431.5 3000 10768

39000 112000 0.79 92.94 5684 342.4 0 0 2.37 3806 3000 431.5 2905 0 431.5 3000 9768

39000 111000 0.79 108.78 6684 462 0 0 2.33 3772 3000 431.5 1905 0 431.5 3000 8768

39000 110000 0.79 124.75 7684 582.7 0 0 2.29 3739 3000 431.5 905 0 431.5 3000 7768

39000 109000 0.79 140.87 8684 704.4 0 0 2.25 3706 3000 384 0 0 384 3000 6768

39000 108000 0.79 157.13 9684 827.2 0 0 2.22 3673 2884 0 0 0 0 2884 5768

39000 107648 0.79 162.89 10036 870.7 0 0 2.2 3662 2708 0 0 0 0 2708 5416

39000 107648 0.79 162.89 10036 870.7 -2337.8 -2.9 2.21 947 2708 0 0 0 0 2708 5416

38036 107641 0.79 163.3 10043 873.8 -2355.1 -2.9 2.02 954 2704.5 0 0 0 0 2704.5 5409

38035 107641 0.79 163.3 10043 873.8 -1708.2 -2.1 2.03 954 2704.5 0 0 0 0 2704.5 5409

37000 107632 0.773 163.91 10052 878.4 -1689.8 -2.2 2.11 935 2700 0 0 0 0 2700 5400

36089 107623 0.758 164.45 10061 882.3 -1687 -2.2 2.18 904 2695.5 0 0 0 0 2695.5 5391

36089 107623 0.758 164.45 10061 882.3 -1788 -2.3 2.18 904 2695.5 0 0 0 0 2695.5 5391

35000 107614 0.741 165.06 10070 886.7 -1787 -2.4 2.24 869 2691 0 0 0 0 2691 5382

34000 107606 0.726 165.62 10078 890.6 -1793.8 -2.4 2.28 833 2687 0 0 0 0 2687 5374

33000 107598 0.711 166.17 10086 894.5 -1808.7 -2.5 2.32 794 2683 0 0 0 0 2683 5366

32000 107591 0.696 166.72 10093 898.2 -1829.8 -2.5 2.36 751 2679.5 0 0 0 0 2679.5 5359

31000 107584 0.682 167.27 10100 901.9 -1815.7 -2.6 2.38 760 2676 0 0 0 0 2676 5352

30000 107577 0.668 167.82 10107 905.6 -1801.4 -2.6 2.4 770 2672.5 0 0 0 0 2672.5 5345

29000 107570 0.655 168.38 10114 909.2 -1791 -2.6 2.42 775 2669 0 0 0 0 2669 5338

28000 107563 0.641 168.94 10121 912.8 -1783.3 -2.6 2.44 775 2665.5 0 0 0 0 2665.5 5331

27000 107556 0.628 169.5 10128 916.3 -1763.9 -2.7 2.47 792 2662 0 0 0 0 2662 5324

26000 107548 0.616 170.07 10136 919.8 -1744.8 -2.7 2.49 810 2658 0 0 0 0 2658 5316

25000 107540 0.604 170.65 10144 923.4 -1727.1 -2.7 2.51 827 2654 0 0 0 0 2654 5308

24000 107533 0.592 171.23 10151 926.8 -1708.8 -2.7 2.52 844 2650.5 0 0 0 0 2650.5 5301

23000 107524 0.58 171.82 10160 930.3 -1692.3 -2.7 2.53 860 2646 0 0 0 0 2646 5292

22000 107516 0.569 172.41 10168 933.8 -1678.5 -2.7 2.53 872 2642 0 0 0 0 2642 5284

21000 107507 0.558 173.01 10177 937.2 -1667.7 -2.8 2.54 880 2637.5 0 0 0 0 2637.5 5275

20000 107498 0.547 173.61 10186 940.6 -1659.6 -2.8 2.55 885 2633 0 0 0 0 2633 5266

19000 107489 0.536 174.22 10195 943.9 -1639.8 -2.8 2.55 910 2628.5 0 0 0 0 2628.5 5257

18000 107480 0.526 174.83 10204 947.3 -1621.3 -2.8 2.56 934 2624 0 0 0 0 2624 5248

17000 107471 0.516 175.45 10213 950.6 -1604.1 -2.8 2.57 957 2619.5 0 0 0 0 2619.5 5239

16000 107461 0.506 176.08 10223 954 -1589.7 -2.8 2.57 977 2614.5 0 0 0 0 2614.5 5229

15000 107450 0.497 176.71 10234 957.3 -1573.9 -2.9 2.58 999 2609 0 0 0 0 2609 5218

14000 107440 0.487 177.35 10244 960.5 -1557.7 -2.9 2.58 1021 2604 0 0 0 0 2604 5208

13000 107429 0.478 177.99 10255 963.8 -1542.9 -2.9 2.58 1041 2598.5 0 0 0 0 2598.5 5197

12000 107418 0.469 178.65 10266 967 -1530 -2.9 2.57 1060 2593 0 0 0 0 2593 5186

11000 107406 0.461 179.3 10278 970.3 -1519.3 -2.9 2.57 1076 2587 0 0 0 0 2587 5174

10000 107394 0.452 179.96 10290 973.5 -1512.7 -3 2.57 1086 2581 0 0 0 0 2581 5162

10000 107394 0.452 179.96 10290 973.5 -1512.7 -3 2.57 1086 2581 0 0 0 0 2581 5162

9000 107382 0.444 180.62 10302 976.6 -1513 -3 2.57 1086 2575 0 0 0 0 2575 5150

8000 107370 0.436 181.28 10314 979.7 -1515 -3.1 2.57 1085 2569 0 0 0 0 2569 5138

7000 107358 0.428 181.94 10326 982.8 -1503.6 -3.1 2.57 1102 2563 0 0 0 0 2563 5126

6000 107346 0.42 182.61 10338 985.8 -1488.8 -3.1 2.57 1124 2557 0 0 0 0 2557 5114

5000 107334 0.413 183.29 10350 988.9 -1475.3 -3.1 2.57 1145 2551 0 0 0 0 2551 5102

4000 107321 0.406 183.97 10363 991.9 -1463.2 -3.1 2.57 1165 2544.5 0 0 0 0 2544.5 5089

3000 107307 0.398 184.66 10377 994.9 -1449.4 -3.1 2.57 1189 2537.5 0 0 0 0 2537.5 5075

2000 107294 0.391 185.35 10390 997.9 -1435.5 -3.2 2.56 1211 2531 0 0 0 0 2531 5062

1500 107287 0.388 185.7 10397 999.4 -1429 -3.2 2.56 1221 2527.5 0 0 0 0 2527.5 5055

0 107132 0 189.38 10552 999.4 0 0 0 0 2450 0 0 0 0 2450 4900

Page 1
med-med-data

A310-308 4000NM, ISA conditions

ALT. A/C WT MACH TIME FUEL DIST RATE GRDT ALPH WFE Loutr Linr Ctr Trim Rinr Routr FOB For Calculation use only!

( FT ) ( KG ) ( ) ( MN ) ( KG ) ( NM ) (FTMN) (DEG.) (DEG.) (KG/H) (kg) (kg) (kg) (kg) (kg) (kg) (kg) delta timedelta fueldelta dist

0 127295 0 0 0 0 0 0 0 0 3000 9532 0 0 9532 3000 25064

0 126170 45 1125 0 0 0 0 1500 3000 8969.5 0 0 8970 3000 23939

1500 125809 0.388 46.64 1486 3.3 3946.3 8.78 3.2 13291 3000 8789 0 0 8789 3000 23578 1.64 361 3.3

2000 125781 0.391 46.76 1514 3.8 3959.5 8.75 3.2 13286 3000 8775 0 0 8775 3000 23550 1.76 389 3.8

3000 125725 0.398 47.02 1570 4.9 3994.8 8.7 3.21 13301 3000 8747 0 0 8747 3000 23494 2.02 445 4.9

4000 125670 0.406 47.27 1625 6 4018 8.62 3.21 13272 3000 8719.5 0 0 8720 3000 23439 2.27 500 6

5000 125615 0.413 47.51 1680 7.1 4092.4 8.66 3.2 13362 3000 8692 0 0 8692 3000 23384 2.51 555 7.1

6000 125561 0.42 47.76 1734 8.2 4116.5 8.59 3.2 13329 3000 8665 0 0 8665 3000 23330 2.76 609 8.2

7000 125507 0.428 48 1788 9.3 4070.5 8.37 3.2 13153 3000 8638 0 0 8638 3000 23276 3 663 9.3

8000 125454 0.436 48.25 1841 10.4 4012.1 8.12 3.2 12967 3000 8611.5 0 0 8612 3000 23223 3.25 716 10.4

9000 125400 0.444 48.5 1895 11.6 3975.1 7.93 3.21 12840 3000 8584.5 0 0 8585 3000 23169 3.5 770 11.6

10000 125346 0.452 48.75 1949 12.8 3930.8 7.73 3.21 12695 3000 8557.5 0 0 8558 3000 23115 3.75 824 12.8

10000 125271 0.541 49.1 2024 14.6 4035.2 6.63 1.55 12907 3000 8520 0 0 8520 3000 23040 4.1 899 14.6

11000 125217 0.551 49.35 2078 16.1 3934 6.37 1.54 12644 3000 8493 0 0 8493 3000 22986 4.35 953 16.1

12000 125164 0.561 49.61 2131 17.6 3824.9 6.1 1.54 12373 3000 8466.5 0 0 8467 3000 22933 4.61 1006 17.6

13000 125109 0.571 49.88 2186 19.2 3710.5 5.83 1.54 12094 3000 8439 0 0 8439 3000 22878 4.88 1061 19.2

14000 125055 0.582 50.15 2240 20.8 3592.4 5.56 1.54 11819 3000 8412 0 0 8412 3000 22824 5.15 1115 20.8

15000 125000 0.593 50.43 2295 22.5 3471.5 5.3 1.53 11552 3000 8384.5 0 0 8385 3000 22769 5.43 1170 22.5

16000 124944 0.604 50.73 2351 24.4 3368.1 5.06 1.53 11332 3000 8356.5 0 0 8357 3000 22713 5.73 1226 24.4

17000 124888 0.615 51.03 2407 26.3 3258.9 4.82 1.51 11097 3000 8328.5 0 0 8329 3000 22657 6.03 1282 26.3

18000 124830 0.627 51.34 2465 28.3 3139.8 4.58 1.5 10842 3000 8299.5 0 0 8300 3000 22599 6.34 1340 28.3

19000 124772 0.639 51.67 2523 30.4 3012.1 4.33 1.48 10570 3000 8270.5 0 0 8271 3000 22541 6.67 1398 30.4

20000 124713 0.651 52 2582 32.6 2875.9 4.07 1.47 10284 3000 8241 0 0 8241 3000 22482 7 1457 32.6

21000 124653 0.664 52.36 2642 35 2782.7 3.88 1.45 10115 3000 8211 0 0 8211 3000 22422 7.36 1517 35

22000 124592 0.677 52.72 2703 37.5 2677 3.68 1.44 9913 3000 8135.5 0 90 8136 3000 22361 7.72 1578 37.5

23000 124530 0.69 53.11 2765 40.1 2559.8 3.46 1.42 9681 3000 8055.8 0 187.5 8056 3000 22299 8.11 1640 40.1

24000 124466 0.703 53.51 2829 42.9 2432.9 3.24 1.41 9422 3000 7973.8 0 287.5 7974 3000 22235 8.51 1704 42.9

25000 124401 0.717 53.93 2894 45.9 2299.7 3.02 1.38 9141 3000 7888.8 0 392.5 7889 3000 22170 8.93 1769 45.9

26000 124334 0.731 54.38 2961 49.2 2189.8 2.83 1.35 8936 3000 7799 0 505 7799 3000 22103 9.38 1836 49.2

27000 124265 0.745 54.84 3030 52.6 2072.6 2.64 1.31 8718 3000 7707 0 620 7707 3000 22034 9.84 1905 52.6

28000 124193 0.76 55.34 3102 56.3 1951.5 2.44 1.27 8489 3000 7608.5 0 745 7609 3000 21962 10.34 1977 56.3

29000 124120 0.775 55.87 3175 60.3 1835 2.26 1.22 8248 3000 7505.8 0 877.5 7506 3000 21889 10.87 2050 60.3

29959 124046 0.79 56.41 3249 64.5 1708.7 2.08 1.16 8009 3000 7401.3 0 1012.5 7401 3000 21815 11.41 2124 64.5

29959 124046 0.79 56.41 3249 64.5 2417.1 2.94 1.16 8009 3000 7401.3 0 1012.5 7401 3000 21815 11.41 2124 64.5

30000 124044 0.79 56.43 3251 64.6 2412.8 2.93 1.16 7999 3000 7397.8 0 1017.5 7398 3000 21813 11.43 2126 64.6

31000 123988 0.79 56.86 3307 67.9 2266.2 2.77 1.31 7690 3000 7316 0 1125 7316 3000 21757 11.86 2182 67.9

32000 123931 0.79 57.31 3364 71.5 2114.9 2.59 1.46 7387 3000 7231.3 0 1237.5 7231 3000 21700 12.31 2239 71.5

33000 123871 0.79 57.8 3424 75.2 1959.5 2.41 1.63 7114 3000 7140 0 1360 7140 3000 21640 12.8 2299 75.2

34000 123809 0.79 58.34 3486 79.3 1796 2.22 1.8 6842 3000 7041.5 0 1495 7042 3000 21578 13.34 2361 79.3

35000 123744 0.79 58.92 3551 83.7 1627.7 2.02 1.98 6574 3000 6936.5 0 1640 6937 3000 21513 13.92 2426 83.7

35000 123745 0.79 58.92 3551 83.7 0 0 1.99 4200 3000 6936.5 0 1640 6937 3000 21513 0 0 0

35000 122000 0.79 83.99 5296 273.9 0 0 1.93 4153 3000 4384 0 5000 4384 3000 19768 25.07 1745 190.2

35000 121000 0.79 98.48 6296 383.9 0 0 1.9 4127 3000 3884 0 5000 3884 3000 18768 39.56 2745 300.2

35000 120000 0.79 113.06 7296 494.6 0 0 1.87 4101 3000 3384 0 5000 3384 3000 17768 54.14 3745 410.9

35000 119000 0.79 127.74 8296 606 0 0 1.84 4076 3000 2884 0 5000 2884 3000 16768 68.82 4745 522.3

35000 118000 0.79 142.5 9296 718 0 0 1.81 4051 3000 2384 0 5000 2384 3000 15768 83.58 5745 634.3

Page 1
med-long-data

A310-308 4000NM, ISA conditions

Fuel Distribution

ALT. A/C WT MACH TIME FUEL DIST RATE GRDT ALPH WFE Loutr Linr Ctr Trim Rinr Routr FOB For Calculation use only!

( FT ) ( KG ) ( ) ( MN ) ( KG ) ( NM ) (FTMN) (DEG.) (DEG.) (KG/H) (kg) (kg) (kg) (kg) (kg) (kg) (kg)

0 148835 0 0 0 0 0 0 0 0 3000 11160 15712 2574 11160 3000 46606 delta timedelta fueldelta dist

0 147710 0 45 1125 0 0 0 0 1500 3000 11160 14587 2574 11160 3000 45481

1500 147273 0.388 46.94 1562 3.9 3198.4 7.11 4.14 13291 3000 10942 14587 2574 10942 3000 45044 1.94 437 3.9

2000 147238 0.391 47.09 1597 4.6 3208.7 7.08 4.14 13286 3000 10942 14552 2574 10942 3000 45009 2.09 472 4.6

3000 147169 0.398 47.4 1666 5.9 3236.7 7.04 4.14 13301 3000 10942 14483 2574 10942 3000 44940 2.4 541 5.9

4000 147101 0.406 47.71 1734 7.3 3254.3 6.98 4.14 13272 3000 10942 14415 2574 10942 3000 44872 2.71 609 7.3

5000 147034 0.413 48.01 1801 8.6 3315.8 7.01 4.13 13362 3000 10942 14348 2574 10942 3000 44805 3.01 676 8.6

6000 146967 0.42 48.31 1868 9.9 3334.1 6.94 4.13 13329 3000 10942 14281 2574 10942 3000 44738 3.31 743 9.9

7000 146900 0.428 48.62 1935 11.3 3292.5 6.76 4.13 13153 3000 10942 14214 2574 10942 3000 44671 3.62 810 11.3

8000 146833 0.436 48.92 2002 12.7 3240.2 6.55 4.13 12967 3000 10942 14147 2574 10942 3000 44604 3.92 877 12.7

9000 146767 0.444 49.23 2068 14.2 3206.1 6.39 4.13 12840 3000 10942 14081 2574 10942 3000 44538 4.23 943 14.2

10000 146700 0.452 49.55 2135 15.7 3165.8 6.22 4.13 12695 3000 10942 14014 2574 10942 3000 44471 4.55 1010 15.7

10000 146607 0.541 49.98 2228 18 3299 5.41 2.17 12907 3000 10942 13921 2574 10942 3000 44378 4.98 1103 18

11000 146542 0.551 50.29 2293 19.7 3210.9 5.19 2.17 12644 3000 10942 13856 2574 10942 3000 44313 5.29 1168 19.7

12000 146476 0.561 50.6 2359 21.6 3115.5 4.96 2.16 12373 3000 10942 13790 2574 10942 3000 44247 5.6 1234 21.6

13000 146410 0.571 50.93 2425 23.5 3015.6 4.74 2.16 12094 3000 10942 13724 2574 10942 3000 44181 5.93 1300 23.5

14000 146342 0.582 51.27 2493 25.6 2912.3 4.51 2.15 11819 3000 10942 13656 2574 10942 3000 44113 6.27 1368 25.6

15000 146274 0.593 51.62 2561 27.7 2806.6 4.28 2.15 11552 3000 10942 13588 2574 10942 3000 44045 6.62 1436 27.7

16000 146205 0.604 51.98 2630 30 2716.1 4.08 2.14 11332 3000 10942 13519 2574 10942 3000 43976 6.98 1505 30

17000 146135 0.615 52.35 2700 32.3 2620.9 3.88 2.12 11097 3000 10942 13449 2574 10942 3000 43906 7.35 1575 32.3

18000 146064 0.627 52.74 2771 34.8 2517.1 3.67 2.1 10842 3000 10942 13378 2574 10942 3000 43835 7.74 1646 34.8

19000 145992 0.639 53.15 2843 37.5 2405.6 3.46 2.08 10570 3000 10942 13306 2574 10942 3000 43763 8.15 1718 37.5

20000 145917 0.651 53.57 2918 40.3 2286.8 3.24 2.06 10284 3000 10942 13231 2574 10942 3000 43688 8.57 1793 40.3

21000 145842 0.664 54.02 2993 43.3 2205 3.07 2.05 10115 3000 10942 10730 5000 10942 3000 43613 9.02 1868 43.3

22000 145764 0.677 54.48 3071 46.4 2112.4 2.9 2.03 9913 3000 10942 10652 5000 10942 3000 43535 9.48 1946 46.4

23000 145685 0.69 54.97 3150 49.8 2010.2 2.72 2.01 9681 3000 10942 10573 5000 10942 3000 43456 9.97 2025 49.8

24000 145604 0.703 55.48 3231 53.4 1899.8 2.53 1.99 9422 3000 10942 10492 5000 10942 3000 43375 10.48 2106 53.4

25000 145520 0.717 56.02 3315 57.2 1785.1 2.34 1.95 9141 3000 10942 10408 5000 10942 3000 43291 11.02 2190 57.2

26000 145433 0.731 56.6 3402 61.4 1690.6 2.18 1.92 8936 3000 10942 10321 5000 10942 3000 43204 11.6 2277 61.4

27000 145344 0.745 57.21 3491 65.9 1591.2 2.02 1.87 8718 3000 10942 10232 5000 10942 3000 43115 12.21 2366 65.9

28000 145250 0.76 57.86 3585 70.7 1490.7 1.87 1.82 8489 3000 10942 10138 5000 10942 3000 43021 12.86 2460 70.7

29000 145153 0.775 58.55 3682 76 1384.3 1.71 1.76 8248 3000 10942 10041 5000 10942 3000 42924 13.55 2557 76

29959 145055 0.79 59.27 3780 81.6 1268.9 1.54 1.69 8009 3000 10942 9943 5000 10942 3000 42826 14.27 2655 81.6

29959 145055 0.79 59.27 3780 81.6 1795 2.18 1.69 8009 3000 10942 9943 5000 10942 3000 42826 14.27 2655 81.6

30000 145052 0.79 59.3 3783 81.7 1790.4 2.18 1.7 7999 3000 10942 9940 5000 10942 3000 42823 14.3 2658 81.7

31000 144976 0.79 59.88 3859 86.3 1638 2 1.87 7690 3000 10942 9864 5000 10942 3000 42747 14.88 2734 86.3

32000 144896 0.79 60.52 3939 91.2 1480 1.81 2.05 7387 3000 10942 9784 5000 10942 3000 42667 15.52 2814 91.2

33000 144809 0.79 61.24 4026 96.7 1313 1.62 2.24 7114 3000 10942 9697 5000 10942 3000 42580 16.24 2901 96.7

34000 144714 0.79 62.06 4121 103 1127.5 1.39 2.44 6842 3000 10942 9602 5000 10942 3000 42485 17.06 2996 103

35000 144604 0.79 63.04 4231 110.4 913.9 1.14 2.65 6574 3000 10942 9492 5000 10942 3000 42375 18.04 3106 110.4

35000 144606 0.79 63.04 4231 110.4 0 0 2.65 4955 3000 10942 9492 5000 10942 3000 42375 0 0 0

35000 143000 0.79 82.64 5837 259.1 0 0 2.6 4880 3000 10942 7886 5000 10942 3000 40769 19.6 1606 148.7

35000 142000 0.79 94.99 6837 352.9 0 0 2.57 4833 3000 10942 6886 5000 10942 3000 39769 31.95 2606 242.5

35000 141000 0.79 107.46 7837 447.5 0 0 2.54 4788 3000 10942 5886 5000 10942 3000 38769 44.42 3606 337.1

35000 140000 0.79 120.05 8837 543.1 0 0 2.51 4745 3000 10942 4886 5000 10942 3000 37769 57.01 4606 432.7

35000 139000 0.79 132.75 9837 639.5 0 0 2.48 4705 3000 10942 3886 5000 10942 3000 36769 69.71 5606 529.1

Page 1
Small Commercial Transport

Short Range Mission

Enroute Temp = STD + 0.000 Degrees C Main 1 Volume = 505.3 gal

Enroute Temp = STD + 0.000 Degrees C Main 2 Volume = 505.3 gal

Ground Time (takeoff) = 1.000 minutes CWT Volume = 0 gal

Ground Time (landing) = 2.000 minutes

Time Time Pressure 

Alt Dist Mach Number Weight Ambient Temp

Ambient 

Temp

Total 

Temp

Fuel 

Flow

Fuel 

Flow

Fuel 

Remainin

g

Main Tank 

1 Fuel 

Remaining

Main Tank 

2 Fuel 

Remaining

CWT 

Fuel 

Remainin

g

Rate of 

Climb / 

Descent

minutes hours feet N. Mi. lbs Degrees C Degrees F Degrees F lb/hr lb/min lbs lbs lbs lbs ft/min

0.0 0.0 0 0.0 0.000 64270 15.0 59.0 59.00 1260 21 6770 3385 3385 0 0

10.0 0.2 0 0.0 0.000 64060 15.0 59.0 59.00 9000 150 6560 3280 3280 0 0

11.5 0.2 1500 1.9 0.388 63851 12.0 53.7 69.11 7471 125 6351 3176 3176 0 3193.7

11.6 0.2 2000 2.6 0.391 63832 11.0 51.9 67.51 7405 123 6332 3166 3166 0 3166.2

12.3 0.2 4000 5.4 0.406 63754 7.1 44.7 61.36 7143 119 6254 3127 3127 0 3053.2

12.9 0.2 6000 8.4 0.420 63676 3.1 37.6 55.15 6887 115 6176 3088 3088 0 2937.1

13.6 0.2 8000 11.5 0.436 63598 -0.8 30.5 49.11 6637 111 6098 3049 3049 0 2816.9

14.4 0.2 10000 15.0 0.452 63519 -4.8 23.3 43.07 6386 106 6019 3010 3010 0 2692.5

15.1 0.3 12000 18.7 0.469 63439 -8.8 16.2 37.14 6148 102 5939 2970 2970 0 2559.1

15.9 0.3 14000 22.7 0.487 63359 -12.7 9.1 31.31 5910 99 5859 2930 2930 0 2421.6

16.8 0.3 16000 27.1 0.506 63276 -16.7 1.9 25.58 5678 95 5776 2888 2888 0 2280.1

17.7 0.3 18000 31.9 0.526 63192 -20.7 -5.2 19.96 5454 91 5692 2846 2846 0 2137.1

18.6 0.3 20000 37.3 0.547 63106 -24.6 -12.3 14.45 5231 87 5606 2803 2803 0 1993.6

19.7 0.3 22000 43.2 0.569 63017 -28.6 -19.5 9.05 5012 84 5517 2759 2759 0 1831.5

20.8 0.3 24000 49.9 0.592 62924 -32.5 -26.6 3.77 4795 80 5424 2712 2712 0 1670.2

22.1 0.4 26000 57.5 0.616 62825 -36.5 -33.7 -1.39 4582 76 5325 2663 2663 0 1502.7

23.5 0.4 28000 66.4 0.641 62720 -40.5 -40.9 -6.44 4375 73 5220 2610 2610 0 1331.1

25.1 0.4 30000 76.8 0.668 62605 -44.4 -48.0 -11.24 4171 70 5105 2553 2553 0 1156.7

27.0 0.4 32000 89.3 0.696 62478 -48.4 -55.1 -15.92 3972 66 4978 2489 2489 0 978

27.2 0.5 32200 90.7 0.699 62464 -48.8 -55.8 -16.37 3952 66 4964 2482 2482 0 959.8

27.3 0.5 32250 91.0 0.700 62461 -48.9 -56.0 -16.45 3947 66 4961 2481 2481 0 955.3

27.9 0.5 33000 95.2 0.700 62421 -50.4 -58.7 -19.39 3852 64 4921 2461 2461 0 1205.1

28.8 0.5 34000 101.0 0.700 62367 -52.4 -62.2 -23.30 3728 62 4867 2434 2434 0 1116.5

29.7 0.5 35000 107.3 0.700 62309 -54.3 -65.8 -27.22 3604 60 4809 2405 2405 0 1019.2

35.8 0.6 35000 152.5 0.770 62000 -54.3 -65.8 -19.11 3039 51 4500 2250 2250 0 0

45.7 0.8 35000 225.6 0.770 61500 -54.3 -65.8 -19.11 3029 50 4000 2000 2000 0 0

55.7 0.9 35000 299.1 0.770 61000 -54.3 -65.8 -19.11 3018 50 3500 1750 1750 0 0

63.1 1.1 35000 355.0 0.770 60620 -54.3 -65.8 -19.11 3009 50 3120 1560 1560 0 0

64.0 1.1 34000 360.7 0.700 60622 -52.4 -62.2 -23.30 2991.6 50 3122 1561 1561 0 433.6

64.3 1.1 33000 362.9 0.700 60620 -50.4 -58.7 -19.39 3054 51 3120 1560 1560 0 445

64.6 1.1 32250 364.6 0.700 60618 -48.9 -56.0 -16.45 2342.2 39 3118 1559 1559 0 457.3

64.6 1.1 32200 364.7 0.699 60618 -48.8 -55.8 -16.37 2340.9 39 3118 1559 1559 0 458

65.1 1.1 31000 368.2 0.682 60614 -46.4 -51.6 -13.59 2312.4 39 3114 1557 1557 0 475.6

65.5 1.1 30000 371.0 0.668 60610 -44.4 -48.0 -11.24 2289 38 3110 1555 1555 0 490.8

66.4 1.1 28000 376.7 0.641 60603 -40.5 -40.9 -6.44 2241.7 37 3103 1552 1552 0 523.5

67.3 1.1 26000 382.4 0.616 60595 -36.5 -33.7 -1.39 2192.5 37 3095 1548 1548 0 558

68.2 1.1 24000 387.9 0.592 60586 -32.5 -26.6 3.77 2143.8 36 3086 1543 1543 0 595.7

69.2 1.2 22000 393.5 0.569 60576 -28.6 -19.5 9.05 2094.6 35 3076 1538 1538 0 635.6

70.1 1.2 20000 398.9 0.547 60566 -24.6 -12.3 14.45 2044.1 34 3066 1533 1533 0 675.2

71.1 1.2 18000 404.4 0.526 60554 -20.7 -5.2 19.96 1991.2 33 3054 1527 1527 0 722.7

72.2 1.2 16000 409.8 0.506 60541 -16.7 1.9 25.58 1938.3 32 3041 1521 1521 0 770.4

73.2 1.2 14000 415.3 0.487 60528 -12.7 9.1 31.31 1883.9 31 3028 1514 1514 0 821.2

74.3 1.2 12000 420.7 0.469 60512 -8.8 16.2 37.14 1828.5 30 3012 1506 1506 0 875.1

75.4 1.3 10000 426.1 0.452 60496 -4.8 23.3 43.07 1773.4 30 2996 1498 1498 0 929.1

76.5 1.3 8000 431.5 0.436 60477 -0.8 30.5 49.11 1717 29 2977 1489 1489 0 989.8

77.7 1.3 6000 436.9 0.420 60457 3.1 37.6 55.15 1661.3 28 2957 1479 1479 0 1053.6

78.9 1.3 4000 442.4 0.406 60435 7.1 44.7 61.36 1604 27 2935 1468 1468 0 1123.9

80.2 1.3 2000 447.9 0.391 60410 11.0 51.9 67.51 1544 26 2910 1455 1455 0 1201.1

80.5 1.3 1500 449.3 0.388 60404 12.0 53.7 69.11 1529.1 25 2904 1452 1452 0 1221.8

81.5 1.4 0 453.5 0.378 60383 15.0 59.0 73.82 1484 25 2883 1442 1442 0 1283.9

83.5 1.4 0 453.5 0.000 60283 15.0 59.0 59.00 3000 50 2783 1392 1392 0 0

Airplane Standards (3).xls, Reg-tfan-data 7/8/98
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A B C D E F G H I J K L M N O P Q R S T

de Havilland Dash 8 Series 301

Total Weight 18640 kg /41000 lbs

Fuel Full Tank 5764 lbs

Time Time Pressure Distance Climb / Rate of Sonic Mach Fuel Fuel Flow Fuel Flow Fuel Tank 1 Tank 2 Weight Ambient Ambient Total

Altitude Descent Climb / Velocity Number Consume RemainingFuel Rem.Fuel Rem. Temp Temp Temp

Speed Descent Total

minutes hours feet n. miles kts ft/min ft/s lbs lbs/hr lbs/min lbs lbs lbs lbs Celcius Farenheit Farenheit

CLIMB 0.00 0.00 0.00 0.00 0.00 0.00 1116.40 0.000 0.00 0.00 0.00 5764.00 2882.00 2882.00 41100.00 15.00 59.00 59.00

Type I High Speed 3.00 0.05 2000.00 8.00 195.00 666.67 1108.70 0.297 77.16 1784.00 29.73 5686.84 2843.42 2843.42 41022.84 11.04 51.87 60.89

Propeller RPM 900 5.00 0.08 4000.00 16.00 195.00 800.00 1101.00 0.299 147.71 1744.00 29.07 5616.29 2808.14 2808.14 40952.29 7.08 44.74 53.75

ISA 8.00 0.13 6000.00 25.00 195.00 750.00 1093.20 0.301 220.46 1712.00 28.53 5543.54 2771.77 2771.77 40879.54 3.11 37.60 46.62

11.00 0.18 8000.00 36.00 195.00 727.27 1085.30 0.303 297.63 1682.00 28.03 5466.37 2733.19 2733.19 40802.37 -0.85 30.47 39.49

14.00 0.23 10000.00 47.00 195.00 714.29 1077.40 0.306 379.20 1658.00 27.63 5384.80 2692.40 2692.40 40720.80 -4.81 23.34 32.36

17.00 0.28 12000.00 58.00 187.00 705.88 1069.40 0.295 462.97 1640.00 27.33 5301.03 2650.51 2650.51 40637.03 -8.77 16.21 24.50

19.00 0.32 14000.00 65.00 179.00 736.84 1061.30 0.285 524.70 1636.00 27.27 5239.30 2619.65 2619.65 40575.30 -12.74 9.07 16.67

21.00 0.35 16000.00 75.00 171.00 761.90 1053.20 0.274 584.23 1540.00 25.67 5179.77 2589.89 2589.89 40515.77 -16.70 1.94 8.88

23.00 0.38 18000.00 85.00 163.00 782.61 1045.10 0.263 650.37 1446.00 24.10 5113.63 2556.82 2556.82 40449.63 -20.66 -5.19 1.11

27.00 0.45 20000.00 95.00 155.00 740.74 1036.80 0.252 716.51 1356.00 22.60 5047.49 2523.75 2523.75 40383.49 -24.62 -12.32 -6.63

CRUISEMax Cruise 30.00 0.50 20000.00 108.55 271.00 0.00 1036.80 0.441 784.26 1356.00 22.60 4979.74 2489.87 2489.87 40315.74 -24.62 -12.32 5.09

Type I Rating 33.00 0.55 20000.00 122.10 271.00 0.00 1036.80 0.441 852.02 1356.00 22.60 4911.98 2455.99 2455.99 40247.98 -24.62 -12.32 5.09

RPM 900 36.00 0.60 20000.00 135.65 271.00 0.00 1036.80 0.441 919.78 1356.00 22.60 4844.22 2422.11 2422.11 40180.22 -24.62 -12.32 5.09

Propeller 39.00 0.65 20000.00 149.21 271.00 0.00 1036.80 0.441 987.54 1356.00 22.60 4776.46 2388.23 2388.23 40112.46 -24.62 -12.32 5.09

ISA 42.00 0.70 20000.00 162.76 271.00 0.00 1036.80 0.441 1055.29 1356.00 22.60 4708.71 2354.35 2354.35 40044.71 -24.62 -12.32 5.09

45.00 0.75 20000.00 176.31 271.00 0.00 1036.80 0.441 1123.05 1356.00 22.60 4640.95 2320.47 2320.47 39976.95 -24.62 -12.32 5.09

48.00 0.80 20000.00 189.86 271.00 0.00 1036.80 0.441 1190.81 1356.00 22.60 4573.19 2286.60 2286.60 39909.19 -24.62 -12.32 5.09

50.00 0.83 20000.00 198.90 271.00 0.00 1036.80 0.441 1235.98 1356.00 22.60 4528.02 2264.01 2264.01 39864.02 -24.62 -12.32 5.09

DESCENT 54.00 0.90 20000.00 215.90 225.00 1250.00 1036.80 0.366 1333.98 1356.00 22.60 4430.02 2215.01 2215.01 39766.02 -24.62 -12.32 -0.32

Type I High Speed 58.00 0.97 18000.00 235.90 225.00 1500.00 1045.10 0.363 1423.98 1350.00 22.50 4340.02 2170.01 2170.01 39676.02 -20.66 -5.19 6.81

Propeller RPM 900 59.00 0.98 16000.00 241.90 225.00 2000.00 1053.20 0.361 1438.98 900.00 15.00 4325.02 2162.51 2162.51 39661.02 -16.70 1.94 13.95

ISA 60.00 1.00 14000.00 246.90 225.00 2000.00 1061.30 0.358 1453.98 900.00 15.00 4310.02 2155.01 2155.01 39646.02 -12.74 9.07 21.08

61.00 1.02 12000.00 251.90 225.00 2000.00 1069.40 0.355 1468.98 900.00 15.00 4295.02 2147.51 2147.51 39631.02 -8.77 16.21 28.21

62.00 1.03 10000.00 255.90 225.00 2000.00 1077.40 0.353 1483.98 900.00 15.00 4280.02 2140.01 2140.01 39616.02 -4.81 23.34 35.34

63.00 1.05 8000.00 260.90 225.00 2000.00 1085.30 0.350 1493.98 600.00 10.00 4270.02 2135.01 2135.01 39606.02 -0.85 30.47 42.48

64.00 1.07 6000.00 264.90 225.00 2000.00 1093.20 0.347 1503.98 600.00 10.00 4260.02 2130.01 2130.01 39596.02 3.11 37.60 49.61

65.00 1.08 4000.00 268.90 225.00 2000.00 1101.00 0.345 1513.98 600.00 10.00 4250.02 2125.01 2125.01 39586.02 7.08 44.74 56.74

66.00 1.10 2000.00 273.90 225.00 2000.00 1108.70 0.343 1523.98 600.00 10.00 4240.02 2120.01 2120.01 39576.02 11.04 51.87 63.87

67.00 1.12 0.00 278.90 0.00 0.00 1116.40 0.000 1533.98 0.00 0.00 4230.02 2115.01 2115.01 39566.02 15.00 59.00 59.00
Airplane Standards (3).xls

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R S T U V W X Y Z

GV - Max Range Mission (6506 NM)

ZFW Ramp Wt Total Fuel Reserve Fuel Landing Wt

49600 90900 41300 2849 52449

Condition Time - MinutesFuel Burn - lbsDistance - NMAirplane Wt - lbs Fuel Remaining - lbs Mach Number Fuel FlowRate of Climb/Descent

lbs/hr ft/min

Ground idle 10 200 0 90700 41100 0.00 -

Takeoff 1 200 0 90500 40900 0.38 12000 -

Climb to 41kft 23 2391 145 88109 38509 0.80 6237 1550

Cruise at 41kft 141 7300 1081 80809 31209 0.80 3106 -

Climb to 43kft 3 181 21 80628 31028 0.80 3620 1500

Cruise at 43kft 150 7100 1145 73528 23928 0.80 2840 -

Climb to 45kft 3 164 21 73364 23764 0.80 3280 1500

Cruise at 45kft 155 6700 1182 66664 17064 0.80 2594 -

Climb to 47kft 3 158 23 66506 16906 0.80 3160 1500

Cruise at 47kft 154 6100 1177 60406 10806 0.80 2377 -

Climb to 49kft 4 158 25 60248 10648 0.80 2370 1000

Cruise at 49kft 157 5700 1204 54548 4948 0.80 2178 -

Climb to 51kft 4 158 29 54390 4790 0.80 2370 1000

Cruise at 51kft 42 1414 317 52976 3376 0.80 2020 -

Descent to 0 ft 23 343 138 52633 3033 0.18 895 2000

Approach-Landing 5 184 0 52449 2849 0.00 2208 -

Page 1
cl-alpha

737

MACH

0 0.45 0.50 0.55 0.60 0.65 0.70 0.72 0.74

Cl 0.3 2.13 1.95 1.93 1.91 1.89 1.87 1.83 1.72 1.66

0.7 6.49 5.77 5.69 5.53 5.35 5.09 4.79 4.65 4.55

747-400

MACH

0.001 0.70 0.76 0.80 0.84 0.88

Wt/Delta 0 1.39 -1.71 -1.97 -2.02 -1.89 -1.52

1600000 12.32 2.40 1.55 1.07 0.67 0.35

1900000 14.37 3.17 2.21 1.65 1.15 0.70

2200000 16.67 3.95 2.86 2.21 1.60 1.06

2500000 19.33 4.75 3.50 2.75 2.05 1.45

2700000 20.72 5.24 3.91 3.10 2.35 1.70

2900000 23.61 5.84 4.32 3.43 2.64 1.95

3100000 26.25 6.43 4.73 3.76 2.92 2.20

747-400 Cruise Body Attitude

-5.00

0.00

5.00

10.00

15.00

20.00

25.00

30.00

0 500000 100000

0

150000

0

200000

0

250000

0

300000

0

350000

0

Weight/Delta (lbs)

Alpha Body (degrees)

0.001

0.70

0.76

0.80

0.84

0.88

Page 1
med-long-data

35000 138000 0.79 145.56 10837 736.7 0 0 2.44 4665 3000 10942 2886 5000 10942 3000 35769 82.52 6606 626.3

35000 137000 0.79 158.47 11837 834.7 0 0 2.41 4625 3000 10942 1886 5000 10942 3000 34769 95.43 7606 724.3

35000 136000 0.79 171.5 12837 933.6 0 0 2.38 4585 3000 10885 1000 5000 10885 3000 33769 108.46 8606 823.2

35000 135000 0.79 184.64 13837 1033.3 0 0 2.35 4550 3000 10385 1000 5000 10385 3000 32769 121.6 9606 922.9

35000 134000 0.79 197.87 14837 1133.7 0 0 2.32 4516 3000 9885 1000 5000 9885 3000 31769 134.83 10606 1023.3

35000 133000 0.79 211.21 15837 1234.9 0 0 2.28 4483 3000 9385 1000 5000 9385 3000 30769 148.17 11606 1124.5

35000 132000 0.79 224.64 16837 1336.9 0 0 2.25 4450 3000 8885 1000 5000 8885 3000 29769 161.6 12606 1226.5

35000 131000 0.79 238.18 17837 1439.6 0 0 2.22 4417 3000 8385 1000 5000 8385 3000 28769 175.14 13606 1329.2

35000 130000 0.79 251.81 18837 1543.1 0 0 2.19 4385 3000 7885 1000 5000 7885 3000 27769 188.77 14606 1432.7

35000 129000 0.79 265.54 19837 1647.3 0 0 2.16 4354 3000 7385 1000 5000 7385 3000 26769 202.5 15606 1536.9

35000 128000 0.79 279.37 20837 1752.2 0 0 2.13 4323 3000 6885 1000 5000 6885 3000 25769 216.33 16606 1641.8

35000 127000 0.79 293.3 21837 1857.9 0 0 2.09 4293 3000 6385 1000 5000 6385 3000 24769 230.26 17606 1747.5

35000 126000 0.79 307.32 22837 1964.4 0 0 2.06 4262 3000 5885 1000 5000 5885 3000 23769 244.28 18606 1854

35000 125000 0.79 321.45 23837 2071.6 0 0 2.03 4235 3000 5385 1000 5000 5385 3000 22769 258.41 19606 1961.2

35000 124000 0.79 335.66 24837 2179.5 0 0 2 4207 3000 4885 1000 5000 4885 3000 21769 272.62 20606 2069.1

35000 123000 0.79 349.97 25837 2288 0 0 1.97 4180 3000 4385 1000 5000 4385 3000 20769 286.93 21606 2177.6

35000 122000 0.79 364.37 26837 2397.3 0 0 1.93 4153 3000 3885 1000 5000 3885 3000 19769 301.33 22606 2286.9

35000 121000 0.79 378.86 27837 2507.3 0 0 1.9 4127 3000 3385 1000 5000 3385 3000 18769 315.82 23606 2396.9

35000 120000 0.79 393.44 28837 2618 0 0 1.87 4101 3000 2885 1000 5000 2885 3000 17769 330.4 24606 2507.6

35000 119000 0.79 408.12 29837 2729.4 0 0 1.84 4076 3000 2385 1000 5000 2385 3000 16769 345.08 25606 2619

35000 118000 0.79 422.88 30837 2841.4 0 0 1.81 4051 3000 1885 1000 5000 1885 3000 15769 359.84 26606 2731

35000 117000 0.79 437.74 31837 2954.2 0 0 1.77 4026 3000 1385 1000 5000 1385 3000 14769 374.7 27606 2843.8

35000 116756 0.79 441.38 32081 2981.8 0 0 1.77 4020 3000 1263 1000 5000 1263 3000 14525 378.34 27850 2871.4

35000 116756 0.79 441.38 32081 2981.8 1866.9 2.32 1.75 6574 3000 1263 1000 5000 1263 3000 14525 0 0 0

36000 116696 0.79 441.94 32141 2986.1 1674.2 2.09 1.94 6270 3000 1233 1000 5000 1233 3000 14465 0.56 60 4.3

36089 116690 0.79 442 32147 2986.5 1518.9 1.9 1.95 6244 3000 1230 1000 5000 1230 3000 14459 0.62 66 4.7

36089 116690 0.79 442 32147 2986.5 1518.9 1.9 1.95 6244 3000 1230 1000 5000 1230 3000 14459 0.62 66 4.7

37000 116625 0.79 442.63 32212 2991.3 1357.4 1.7 2.13 6007 3000 1197 1000 5000 1197 3000 14394 1.25 131 9.5

38000 116548 0.79 443.42 32289 2997.2 1172.6 1.46 2.33 5756 3000 1159 1000 5000 1159 3000 14317 2.04 208 15.4

39000 116459 0.79 444.37 32378 3004.4 944.6 1.18 2.53 5461 3000 1114 1000 5000 1114 3000 14228 2.99 297 22.6

39000 116460 0.79 444.37 32378 3004.4 0 0 2.54 3987 3000 1114 1000 5000 1114 3000 14228 0 0 0

39000 115000 0.79 466.51 33838 3171.6 0 0 2.49 3925 3000 384 1000 5000 384 3000 12768 22.14 1460 167.2

39000 114000 0.79 481.88 34838 3287.7 0 0 2.45 3885 3000 384 1000 4000 384 3000 11768 37.51 2460 283.3

39000 113000 0.79 497.4 35838 3404.9 0 0 2.41 3845 3000 384 1000 3000 384 3000 10768 53.03 3460 400.5

39000 112000 0.79 513.08 36838 3523.3 0 0 2.37 3806 3000 384 1000 2000 384 3000 9768 68.71 4460 518.9

39000 111000 0.79 528.92 37838 3642.9 0 0 2.33 3772 3000 384 1000 1000 384 3000 8768 84.55 5460 638.5

39000 110000 0.79 544.89 38838 3763.6 0 0 2.29 3739 3000 384 1000 0 384 3000 7768 100.52 6460 759.2

39000 109171 0.79 558.25 39667 3864.4 0 0 2.26 3711 3000 384 171 0 384 3000 6939 113.88 7289 860

39000 109171 0.79 558.25 39667 3864.4 -2344 -2.9 2.27 947 3000 384 171 0 384 3000 6939 0 0 0

38035 109165 0.79 558.66 39673 3867.5 -1708.7 -2.1 2.08 954 3000 384 165 0 384 3000 6933 0.41 6 3.1

37000 109155 0.773 559.27 39683 3872 -1688.7 -2.2 2.17 935 3000 384 155 0 384 3000 6923 1.02 16 7.6

36089 109146 0.758 559.81 39692 3876 -1786.4 -2.3 2.23 904 3000 384 146 0 384 3000 6914 1.56 25 11.6

35000 109137 0.741 560.42 39701 3880.4 -1784.7 -2.4 2.3 869 3000 384 137 0 384 3000 6905 2.17 34 16

34000 109129 0.726 560.98 39709 3884.3 -1790.6 -2.4 2.34 833 3000 384 129 0 384 3000 6897 2.73 42 19.9

33000 109121 0.711 561.54 39717 3888.2 -1804.6 -2.5 2.38 794 3000 384 121 0 384 3000 6889 3.29 50 23.8

32000 109114 0.696 562.09 39724 3891.9 -1824.7 -2.5 2.42 751 3000 384 114 0 384 3000 6882 3.84 57 27.5

31000 109107 0.682 562.64 39731 3895.6 -1810 -2.6 2.44 760 3000 384 107 0 384 3000 6875 4.39 64 31.2

30000 109100 0.668 563.19 39738 3899.3 -1795.3 -2.6 2.46 770 3000 384 100 0 384 3000 6868 4.94 71 34.9

29000 109093 0.655 563.75 39745 3902.9 -1784.6 -2.6 2.49 775 3000 384 93 0 384 3000 6861 5.5 78 38.5

28000 109086 0.641 564.31 39752 3906.5 -1776.6 -2.6 2.51 775 3000 384 86 0 384 3000 6854 6.06 85 42.1

Page 2
med-long-data

27000 109079 0.628 564.88 39759 3910.1 -1757.1 -2.7 2.53 792 3000 384 79 0 384 3000 6847 6.63 92 45.7

26000 109071 0.616 565.45 39767 3913.6 -1737.9 -2.7 2.55 810 3000 384 71 0 384 3000 6839 7.2 100 49.2

25000 109063 0.604 566.03 39775 3917.2 -1720.1 -2.7 2.58 827 3000 384 63 0 384 3000 6831 7.78 108 52.8

24000 109055 0.592 566.61 39783 3920.7 -1701.8 -2.7 2.59 844 3000 384 55 0 384 3000 6823 8.36 116 56.3

23000 109047 0.58 567.2 39791 3924.2 -1685.3 -2.7 2.59 860 3000 384 47 0 384 3000 6815 8.95 124 59.8

22000 109038 0.569 567.8 39800 3927.6 -1671.7 -2.7 2.6 872 3000 384 38 0 384 3000 6806 9.55 133 63.2

21000 109030 0.558 568.4 39808 3931.1 -1660.9 -2.8 2.61 880 3000 384 30 0 384 3000 6798 10.15 141 66.7

20000 109021 0.547 569 39817 3934.5 -1652.9 -2.8 2.61 885 3000 384 21 0 384 3000 6789 10.75 150 70.1

19000 109012 0.536 569.61 39826 3937.8 -1633.4 -2.8 2.62 910 3000 384 12 0 384 3000 6780 11.36 159 73.4

18000 109003 0.526 570.23 39835 3941.2 -1615 -2.8 2.63 934 3000 384 3 0 384 3000 6771 11.98 168 76.8

17000 108993 0.516 570.85 39845 3944.6 -1597.9 -2.8 2.63 957 3000 381 0 0 381 3000 6761 12.6 178 80.2

16000 108983 0.506 571.48 39855 3947.9 -1583.5 -2.8 2.64 977 3000 376 0 0 376 3000 6751 13.23 188 83.5

15000 108973 0.497 572.11 39865 3951.2 -1567.7 -2.9 2.64 999 3000 371 0 0 371 3000 6741 13.86 198 86.8

14000 108962 0.487 572.75 39876 3954.5 -1551.5 -2.9 2.64 1021 3000 365 0 0 365 3000 6730 14.5 209 90.1

13000 108951 0.478 573.4 39887 3957.8 -1536.7 -2.9 2.64 1041 3000 360 0 0 360 3000 6719 15.15 220 93.4

12000 108940 0.469 574.06 39898 3961 -1523.8 -2.9 2.64 1060 3000 354 0 0 354 3000 6708 15.81 231 96.6

11000 108928 0.461 574.71 39910 3964.3 -1513 -2.9 2.64 1076 3000 348 0 0 348 3000 6696 16.46 243 99.9

10000 108917 0.452 575.38 39921 3967.5 -1506.3 -3 2.64 1086 3000 343 0 0 343 3000 6685 17.13 254 103.1

9000 108905 0.444 576.04 39933 3970.6 -1506.5 -3 2.64 1086 3000 337 0 0 337 3000 6673 17.79 266 106.2

8000 108892 0.436 576.7 39945 3973.8 -1508.2 -3 2.64 1085 3000 331 0 0 331 3000 6661 18.45 278 109.4

7000 108881 0.428 577.37 39957 3976.9 -1496.7 -3.1 2.64 1102 3000 325 0 0 325 3000 6649 19.12 290 112.5

6000 108868 0.42 578.04 39970 3979.9 -1482 -3.1 2.64 1124 3000 318 0 0 318 3000 6636 19.79 303 115.5

5000 108856 0.413 578.72 39982 3983 -1468.5 -3.1 2.64 1145 3000 312 0 0 312 3000 6624 20.47 315 118.6

4000 108843 0.406 579.4 39995 3986 -1456.4 -3.1 2.64 1165 3000 306 0 0 306 3000 6611 21.15 328 121.6

3000 108829 0.398 580.09 40009 3989 -1442.7 -3.1 2.64 1189 3000 299 0 0 299 3000 6597 21.84 342 124.6

2000 108816 0.391 580.79 40022 3992 -1428.8 -3.1 2.63 1211 3000 292 0 0 292 3000 6584 22.54 355 127.6

1500 108808 0.388 581.14 40030 3993.5 -1422.3 -3.2 2.63 1221 3000 288 0 0 288 3000 6576 22.89 363 129.1

0 108655 0 584.79 40183 3993.5 0 0 0 0 3000 212 0 0 212 3000 6423 26.54 516 129.1

Page 3
med-med-data

35000 117000 0.79 157.36 10296 830.8 0 0 1.77 4026 3000 1884 0 5000 1884 3000 14768 98.44 6745 747.1

35000 116748 0.79 161.12 10548 859.3 0 0 1.77 4020 3000 1758 0 5000 1758 3000 14516 102.2 6997 775.6

35000 116748 0.79 161.12 10548 859.3 1867.1 2.32 1.75 6574 3000 1758 0 5000 1758 3000 14516 0 0 0

36000 116688 0.79 161.68 10608 863.6 1674.5 2.09 1.94 6270 3000 1728 0 5000 1728 3000 14456 0.56 60 4.3

36089 116682 0.79 161.74 10614 864 1519.2 1.9 1.95 6244 3000 1725 0 5000 1725 3000 14450 0.62 66 4.7

36089 116682 0.79 161.74 10614 864 1519.2 1.9 1.95 6244 3000 1725 0 5000 1725 3000 14450 0.62 66 4.7

37000 116617 0.79 162.37 10679 868.8 1357.7 1.7 2.13 6007 3000 1692.5 0 5000 1693 3000 14385 1.25 131 9.5

38000 116540 0.79 163.16 10756 874.7 1172.9 1.46 2.33 5756 3000 1654 0 5000 1654 3000 14308 2.04 208 15.4

39000 116451 0.79 164.11 10845 881.9 944.9 1.18 2.53 5461 3000 1609.5 0 5000 1610 3000 14219 2.99 297 22.6

39000 116452 0.79 164.11 10845 881.9 0 0 2.54 3986 3000 1609.5 0 5000 1610 3000 14219 0 0 0

39000 115000 0.79 186.13 12297 1048.2 0 0 2.49 3925 3000 883.5 0 5000 883.5 3000 12767 22.02 1452 166.3

39000 114000 0.79 201.5 13297 1164.3 0 0 2.45 3885 3000 383.5 1000 4000 383.5 3000 11767 37.39 2452 282.4

39000 113000 0.79 217.02 14297 1281.5 0 0 2.41 3845 3000 0 1000 3767 0 3000 10767 52.91 3452 399.6

39000 112000 0.79 232.7 15297 1399.9 0 0 2.37 3806 3000 0 1000 2767 0 3000 9767 68.59 4452 518

39000 111000 0.79 248.54 16297 1519.5 0 0 2.33 3772 3000 0 1000 1767 0 3000 8767 84.43 5452 637.6

39000 110000 0.79 264.51 17297 1640.2 0 0 2.29 3739 3000 0 1000 767 0 3000 7767 100.4 6452 758.3

39000 109000 0.79 280.63 18297 1761.9 0 0 2.25 3706 3000 0 767 0 0 3000 6767 116.52 7452 880

39000 108119 0.79 294.95 19178 1870 0 0 2.22 3677 2943 0 0 0 0 2943 5886 130.84 8333 988.1

39000 108119 0.79 294.95 19178 1870 -2339.7 -2.9 2.23 947 2943 0 0 0 0 2943 5886 0 0 0

38036 108112 0.79 295.36 19185 1873.1 -2354.9 -2.9 2.04 954 2939.5 0 0 0 0 2939.5 5879 0.41 7 3.1

38035 108112 0.79 295.36 19185 1873.1 -1708 -2.1 2.04 954 2939.5 0 0 0 0 2939.5 5879 0.41 7 3.1

37000 108103 0.773 295.97 19194 1877.6 -1689.4 -2.2 2.13 935 2935 0 0 0 0 2935 5870 1.02 16 7.6

36089 108094 0.758 296.51 19203 1881.6 -1686.5 -2.2 2.19 904 2930.5 0 0 0 0 2930.5 5861 1.56 25 11.6

36089 108094 0.758 296.51 19203 1881.6 -1787.5 -2.3 2.19 904 2930.5 0 0 0 0 2930.5 5861 1.56 25 11.6

35000 108085 0.741 297.12 19212 1886 -1786.2 -2.4 2.26 869 2926 0 0 0 0 2926 5852 2.17 34 16

34000 108077 0.726 297.68 19220 1889.9 -1792.7 -2.4 2.3 833 2922 0 0 0 0 2922 5844 2.73 42 19.9

33000 108069 0.711 298.23 19228 1893.8 -1807.4 -2.5 2.34 794 2918 0 0 0 0 2918 5836 3.28 50 23.8

32000 108062 0.696 298.78 19235 1897.5 -1828.1 -2.5 2.38 751 2914.5 0 0 0 0 2914.5 5829 3.83 57 27.5

31000 108055 0.682 299.33 19242 1901.2 -1813.9 -2.6 2.4 760 2911 0 0 0 0 2911 5822 4.38 64 31.2

30000 108048 0.668 299.89 19249 1904.9 -1799.5 -2.6 2.42 770 2907.5 0 0 0 0 2907.5 5815 4.94 71 34.9

29000 108041 0.655 300.44 19256 1908.5 -1789 -2.6 2.44 775 2904 0 0 0 0 2904 5808 5.49 78 38.5

28000 108034 0.641 301 19263 1912.1 -1781.2 -2.6 2.46 775 2900.5 0 0 0 0 2900.5 5801 6.05 85 42.1

27000 108027 0.628 301.57 19270 1915.6 -1761.8 -2.7 2.49 792 2897 0 0 0 0 2897 5794 6.62 92 45.6

26000 108019 0.616 302.14 19278 1919.2 -1742.6 -2.7 2.51 810 2893 0 0 0 0 2893 5786 7.19 100 49.2

25000 108011 0.604 302.72 19286 1922.7 -1724.9 -2.7 2.53 827 2889 0 0 0 0 2889 5778 7.77 108 52.7

24000 108003 0.592 303.3 19294 1926.2 -1706.6 -2.7 2.54 844 2885 0 0 0 0 2885 5770 8.35 116 56.2

23000 107995 0.58 303.89 19302 1929.7 -1690.1 -2.7 2.55 860 2881 0 0 0 0 2881 5762 8.94 124 59.7

22000 107987 0.569 304.48 19310 1933.1 -1676.5 -2.7 2.55 872 2877 0 0 0 0 2877 5754 9.53 132 63.1

21000 107978 0.558 305.08 19319 1936.6 -1665.7 -2.8 2.56 880 2872.5 0 0 0 0 2872.5 5745 10.13 141 66.6

20000 107969 0.547 305.68 19328 1939.9 -1657.6 -2.8 2.57 885 2868 0 0 0 0 2868 5736 10.73 150 69.9

19000 107960 0.536 306.29 19337 1943.3 -1637.8 -2.8 2.57 910 2863.5 0 0 0 0 2863.5 5727 11.34 159 73.3

18000 107951 0.526 306.9 19346 1946.7 -1619.3 -2.8 2.58 934 2859 0 0 0 0 2859 5718 11.95 168 76.7

17000 107941 0.516 307.52 19356 1950 -1602.1 -2.8 2.59 957 2854 0 0 0 0 2854 5708 12.57 178 80

16000 107932 0.506 308.15 19365 1953.3 -1587.7 -2.8 2.59 977 2849.5 0 0 0 0 2849.5 5699 13.2 187 83.3

15000 107921 0.497 308.78 19376 1956.6 -1572 -2.9 2.6 999 2844 0 0 0 0 2844 5688 13.83 198 86.6

14000 107911 0.487 309.42 19386 1959.9 -1555.7 -2.9 2.6 1021 2839 0 0 0 0 2839 5678 14.47 208 89.9

13000 107900 0.478 310.07 19397 1963.2 -1540.9 -2.9 2.6 1041 2833.5 0 0 0 0 2833.5 5667 15.12 219 93.2

12000 107888 0.469 310.72 19409 1966.4 -1528.1 -2.9 2.59 1060 2827.5 0 0 0 0 2827.5 5655 15.77 231 96.4

11000 107877 0.461 311.38 19420 1969.7 -1517.3 -2.9 2.59 1076 2822 0 0 0 0 2822 5644 16.43 242 99.7

10000 107865 0.452 312.04 19432 1972.9 -1510.7 -3 2.59 1086 2816 0 0 0 0 2816 5632 17.09 254 102.9

Page 2
med-med-data

10000 107865 0.452 312.04 19432 1972.9 -1510.7 -3 2.59 1086 2816 0 0 0 0 2816 5632 17.09 254 102.9

9000 107853 0.444 312.7 19444 1976 -1511 -3 2.59 1086 2810 0 0 0 0 2810 5620 17.75 266 106

8000 107841 0.436 313.36 19456 1979.1 -1512.9 -3.1 2.59 1085 2804 0 0 0 0 2804 5608 18.41 278 109.1

7000 107829 0.428 314.02 19468 1982.2 -1501.4 -3.1 2.59 1102 2798 0 0 0 0 2798 5596 19.07 290 112.2

6000 107817 0.42 314.69 19480 1985.3 -1486.6 -3.1 2.59 1124 2792 0 0 0 0 2792 5584 19.74 302 115.3

5000 107804 0.413 315.37 19493 1988.3 -1473.2 -3.1 2.59 1145 2785.5 0 0 0 0 2785.5 5571 20.42 315 118.3

4000 107791 0.406 316.05 19506 1991.3 -1461.1 -3.1 2.59 1165 2779 0 0 0 0 2779 5558 21.1 328 121.3

3000 107778 0.398 316.74 19519 1994.3 -1447.3 -3.1 2.59 1189 2772.5 0 0 0 0 2772.5 5545 21.79 341 124.3

2000 107764 0.391 317.43 19533 1997.3 -1433.4 -3.2 2.58 1211 2765.5 0 0 0 0 2765.5 5531 22.48 355 127.3

1500 107757 0.388 317.78 19540 1998.8 -1426.9 -3.2 2.58 1221 2762 0 0 0 0 2762 5524 22.83 362 128.8

0 107603 0 321.46 19694 1998.8 0 0 0 0 2685 0 0 0 0 2685 5370 26.51 516 128.8

Page 3
descent

22000 22000 0.2049 60.4 104717 310 1940 0.5687 1062

20000 20000 0.1875 54.5 104698 291 1892 0.5469 1132

18000 18000 0.1696 48.6 104677 270 1841 0.526 1206

16000 16000 0.1513 42.7 104654 247 1790 0.5062 1283

14000 14000 0.1324 36.9 104629 222 1740 0.4874 1365

12000 12000 0.113 31 104602 195 1690 0.4694 1450

10000 10000 0.0929 25.2 104572 165 1639 0.4523 1540

8000 8000 0.0723 19.3 104539 132 1590 0.436 1633

6000 6000 0.051 13.4 104503 96 1539 0.4204 1732

4000 4000 0.0289 7.5 104464 56 1482 0.4056 1853

2000 2000 0.0059 1.5 104419 12 1420 0.3914 2004

1500 1500 0 0 104407 0 1404 0.388 2045

ENROUTE DESC ENT ANALYSIS

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

35000 35000 0.3086 100.2 105424 401 3090 0.74 760

34923 34923 0.3082 100 105424 401 3094 0.74 760

34923 34923 0.3082 100 105424 401 2269 0.74 760

34000 34000 0.3014 97.1 105419 396 2233 0.7258 760

32000 32000 0.2863 90.9 105407 384 2189 0.6962 775

30000 30000 0.2709 84.7 105395 372 2138 0.6681 820

28000 28000 0.2551 78.6 105381 359 2085 0.6414 877

26000 26000 0.2389 72.6 105367 344 2034 0.6159 933

24000 24000 0.2223 66.5 105351 328 1983 0.5917 996

22000 22000 0.2053 60.6 105333 310 1936 0.5687 1062

20000 20000 0.1879 54.6 105314 291 1888 0.5469 1132

18000 18000 0.17 48.7 105293 270 1838 0.526 1206

16000 16000 0.1516 42.8 105270 247 1787 0.5062 1283

14000 14000 0.1326 36.9 105245 222 1737 0.4874 1365

12000 12000 0.1132 31.1 105218 195 1686 0.4694 1450

10000 10000 0.0931 25.2 105188 165 1636 0.4523 1540

8000 8000 0.0724 19.3 105155 132 1587 0.436 1633

6000 6000 0.051 13.4 105119 96 1537 0.4204 1732

4000 4000 0.0289 7.5 105079 56 1480 0.4056 1853

2000 2000 0.0059 1.5 105035 12 1417 0.3914 2004

1500 1500 0 0 105023 0 1402 0.388 2045

LARGE AIRPLANE

ENROUTE DESC ENT ANALYSIS

Page 2
descent

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

43000 43000 0.3722 134.8 488363 1714 3026 0.85 2524

42000 42000 0.3667 132.1 488349 1700 3028 0.85 2622

40000 40000 0.3558 126.8 488319 1671 3068 0.85 2817

38000 38000 0.3451 121.6 488288 1640 3178 0.85 2980

36672 36672 0.3382 118.2 488267 1619 3277 0.85 3087

36672 36672 0.3382 118.2 488267 1619 2292 0.85 3087

36089 36089 0.334 116.2 488254 1606 2257 0.8399 3120

36089 36089 0.334 116.2 488254 1606 2417 0.8399 3120

36000 36000 0.3333 115.9 488252 1604 2412 0.8384 3124

34000 34000 0.3193 109.2 488208 1559 2336 0.8047 3213

32000 32000 0.3049 102.6 488161 1512 2286 0.7727 3304

30000 30000 0.2901 96.1 488111 1463 2239 0.7422 3407

28000 28000 0.2751 89.6 488058 1410 2180 0.7131 3571

26000 26000 0.2596 83.1 488002 1353 2124 0.6853 3738

24000 24000 0.2436 76.7 487941 1292 2066 0.6589 3926

22000 22000 0.2273 70.3 487875 1226 2008 0.6338 4135

20000 20000 0.2104 63.9 487803 1155 1954 0.6098 4346

18000 18000 0.1932 57.6 487727 1078 1914 0.5869 4542

16000 16000 0.1756 51.3 487645 997 1881 0.5651 4749

14000 14000 0.1577 45.1 487558 909 1841 0.5443 5023

12000 12000 0.1394 38.9 487462 814 1793 0.5245 5359

12000 12000 0.1394 38.9 487462 814 1250 0.5245 5359

10000 10000 0.109 29.5 487293 645 976 0.4523 5704

10000 10000 0.109 29.5 487293 645 1370 0.4523 5704

8000 8000 0.0843 22.5 487152 503 1336 0.436 5810

6000 6000 0.0591 15.6 487003 355 1303 0.4204 5924

4000 4000 0.0331 8.6 486849 200 1269 0.4056 6008

2000 2000 0.0067 1.7 486689 40 1250 0.3914 6061

1500 1500 0 0 486648 0 1249 0.388 6074

ENROUTE DESC ENT ANALYSIS

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

39000 39000 0.3518 124.7 493096 1661 3105 0.85 2899

38000 38000 0.3464 122.1 493080 1646 3164 0.85 2980

36672 36672 0.3396 118.7 493059 1625 3261 0.85 3087

36672 36672 0.3396 118.7 493059 1625 2280 0.85 3087

36089 36089 0.3353 116.6 493046 1612 2246 0.8399 3120

Page 3
descent

36089 36089 0.3353 116.6 493046 1612 2404 0.8399 3120

36000 36000 0.3346 116.3 493044 1610 2400 0.8384 3124

34000 34000 0.3205 109.7 492999 1565 2325 0.8047 3213

32000 32000 0.306 103 492952 1518 2275 0.7727 3304

30000 30000 0.2912 96.5 492902 1468 2229 0.7422 3407

28000 28000 0.2761 89.9 492850 1415 2170 0.7131 3571

26000 26000 0.2605 83.5 492793 1358 2115 0.6853 3738

24000 24000 0.2445 77 492731 1297 2057 0.6589 3926

22000 22000 0.2281 70.6 492665 1231 1999 0.6338 4135

20000 20000 0.2112 64.1 492593 1159 1945 0.6098 4346

18000 18000 0.1939 57.8 492516 1082 1906 0.5869 4542

16000 16000 0.1762 51.5 492434 1000 1872 0.5651 4749

14000 14000 0.1582 45.2 492346 912 1833 0.5443 5023

12000 12000 0.1398 39 492251 816 1785 0.5245 5359

12000 12000 0.1398 39 492251 816 1244 0.5245 5359

10000 10000 0.1093 29.6 492081 647 973 0.4523 5704

10000 10000 0.1093 29.6 492081 647 1366 0.4523 5704

8000 8000 0.0846 22.6 491939 504 1332 0.436 5810

6000 6000 0.0592 15.6 491790 356 1300 0.4204 5924

4000 4000 0.0332 8.6 491635 201 1266 0.4056 6008

2000 2000 0.0067 1.7 491475 41 1247 0.3914 6061

1500 1500 0 0 491434 0 1245 0.388 6074

ENROUTE DESC ENT ANALYSIS

WIN D (KNO TS) = 0 DTEMP (DEG

HPR HGEO TIME DIST WEIGHTFUEL ROD MACH T FF

FT FT HR NM LB LB FPM LB/HR

39000 39000 0.3534 125.2 498769 1669 3093 0.85 2899

38000 38000 0.348 122.6 498754 1653 3149 0.85 2980

36672 36672 0.3411 119.3 498733 1632 3242 0.85 3087

36672 36672 0.3411 119.3 498733 1632 2267 0.85 3087

36089 36089 0.3368 117.2 498719 1618 2233 0.8399 3120

36089 36089 0.3368 117.2 498719 1618 2391 0.8399 3120

36000 36000 0.3361 116.9 498717 1617 2386 0.8384 3124

34000 34000 0.3219 110.2 498672 1572 2311 0.8047 3213

32000 32000 0.3074 103.5 498625 1524 2262 0.7727 3304

30000 30000 0.2925 96.9 498575 1474 2217 0.7422 3407

28000 28000 0.2772 90.3 498522 1421 2159 0.7131 3571

26000 26000 0.2616 83.8 498465 1364 2104 0.6853 3738

24000 24000 0.2455 77.3 498403 1302 2046 0.6589 3926

22000 22000 0.229 70.9 498336 1235 1989 0.6338 4135

20000 20000 0.212 64.4 498264 1163 1935 0.6098 4346

18000 18000 0.1946 58 498187 1086 1896 0.5869 4542

16000 16000 0.1769 51.6 498105 1004 1862 0.5651 4749

Page 4
descent

14000 14000 0.1588 45.4 498016 915 1823 0.5443 5023

12000 12000 0.1403 39.1 497920 819 1776 0.5245 5359

12000 12000 0.1403 39.1 497920 819 1237 0.5245 5359

10000 10000 0.1096 29.7 497750 649 970 0.4523 5704

10000 10000 0.1096 29.7 497750 649 1362 0.4523 5704

8000 8000 0.0848 22.7 497607 506 1328 0.436 5810

6000 6000 0.0594 15.6 497458 357 1295 0.4204 5924

4000 4000 0.0333 8.7 497302 201 1262 0.4056 6008

2000 2000 0.0067 1.7 497142 41 1243 0.3914 6061

1500 1500 0 0 497101 0 1241 0.388 6074

Page 5
cruise

ENROUTECRUISE ANALYSIS 35000 0 (FEET)

WIND (KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCETIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

125019 0 0 0 0.08033 429.634 5348.6 0.74535

123964 85.1 0.1982 1055 0.08106 429.647 5300.1 0.74537

122905 171.3 0.3988 2114 0.0818 429.646 5252.6 0.74537

121847 258.3 0.6012 3172 0.08252 429.63 5206.3 0.74534

120789 346 0.8054 4231 0.08324 429.601 5160.9 0.74529

119730 434.5 1.0114 5289 0.08396 429.558 5116 0.74522

118672 523.8 1.2192 6347 0.08468 429.5 5072.3 0.74512

117613 613.8 1.4287 7406 0.08538 429.432 5029.8 0.745

116555 704.5 1.64 8464 0.08607 429.432 4989.1 0.745

115496 796 1.853 9523 0.08676 429.432 4949.5 0.745

114438 888.2 2.0677 10581 0.08744 429.432 4911 0.745

113379 981.1 2.2841 11640 0.08812 429.432 4873.3 0.745

112321 1074.7 2.5021 12698 0.08879 429.432 4836.6 0.745

111263 1169 2.7217 13757 0.08945 429.432 4800.7 0.745

110204 1264 2.943 14815 0.09011 429.432 4765.7 0.745

109146 1359.8 3.1659 15873 0.09076 429.432 4731.5 0.745

108087 1456.2 3.3904 16932 0.09141 429.432 4698.1 0.745

107029 1553.3 3.6165 17990 0.09205 429.432 4665.4 0.745

105970 1651 3.8441 19049 0.09268 429.432 4633.4 0.745

105424 1701.7 3.9622 19595 0.09301 429.42 4616.9 0.74498

LARGE AIRPLANE

ENROUTE CRUISEANALYSIS 39000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

559723 0 0 0 0.02341 487.534 20826.3 0.85

557761 46 0.0944 1962 0.02349 487.534 20758 0.85

552682 165.8 0.3401 7041 0.02368 487.534 20584.2 0.85

547603 286.6 0.5878 12120 0.02388 487.534 20415.9 0.85

542525 408.4 0.8376 17199 0.02407 487.534 20253.4 0.85

537446 531.1 1.0894 22278 0.02426 487.534 20095.5 0.85

Page 2
cruise

532367 654.8 1.3431 27357 0.02445 487.534 19940.3 0.85

527288 779.4 1.5987 32436 0.02464 487.534 19789.3 0.85

522209 905 1.8564 37514 0.02482 487.534 19640.5 0.85

517130 1031.6 2.1159 42593 0.02501 487.534 19494.4 0.85

512051 1159.1 2.3774 47672 0.02519 487.534 19351.4 0.85

510274 1203.9 2.4694 49450 0.02526 487.534 19302.1 0.85

ENROUTE CRUISEANALYSIS 43000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

508348 0 0 0 0.02533 487.534 19249.2 0.85

505898 62.2 0.1276 2450 0.02546 487.534 19149.8 0.85

503037 135.3 0.2775 5311 0.02561 487.534 19035.5 0.85

500175 208.8 0.4282 8172 0.02577 487.534 18922.2 0.85

497314 282.7 0.5799 11034 0.02592 487.534 18810.8 0.85

494453 357.1 0.7325 13895 0.02607 487.534 18698.1 0.85

491591 431.9 0.886 16756 0.02623 487.534 18584.4 0.85

488730 507.2 1.0404 19618 0.02639 487.534 18471.7 0.85

488363 516.9 1.0603 19985 0.02641 487.534 18457.3 0.85

ENROUTE CRUISEANALYSIS 35000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

658800 0 0 0 0.02002 489.956 24470.7 0.85

651689 143.1 0.292 7111 0.02022 489.956 24233.4 0.85

643927 300.8 0.614 14873 0.02043 489.956 23984.9 0.85

636164 460.2 0.9393 22636 0.02063 489.956 23745.3 0.85

628401 621.2 1.2678 30398 0.02084 489.956 23509.9 0.85

620639 783.7 1.5996 38161 0.02105 489.956 23281.2 0.85

620477 787.1 1.6066 38323 0.02105 489.956 23276.5 0.85

ENROUTE CRUISEANALYSIS 39000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

Page 3
cruise

618279 0 0 0 0.02111 487.534 23098.3 0.85

613629 98.6 0.2022 4650 0.02129 487.534 22903.3 0.85

608550 207.2 0.4249 9729 0.02148 487.534 22695.8 0.85

603471 316.8 0.6497 14808 0.02168 487.534 22491 0.85

598392 427.4 0.8766 19887 0.02188 487.534 22285.1 0.85

593313 539 1.1056 24966 0.02208 487.534 22080.5 0.85

588234 651.7 1.3366 30044 0.02228 487.534 21878.8 0.85

583155 765.3 1.5698 35123 0.02249 487.534 21681.1 0.85

578077 880.1 1.8051 40202 0.02269 487.534 21487.7 0.85

572998 995.8 2.0426 45281 0.02289 487.534 21299.2 0.85

567919 1112.6 2.282 50360 0.02309 487.534 21115.6 0.85

562840 1230.3 2.5236 55439 0.02329 487.534 20936.2 0.85

557761 1349.1 2.7672 60518 0.02349 487.534 20758 0.85

552682 1468.9 3.0129 65597 0.02368 487.534 20584.2 0.85

547603 1589.7 3.2607 70675 0.02388 487.534 20415.9 0.85

542525 1711.5 3.5105 75754 0.02407 487.534 20253.4 0.85

537446 1834.2 3.7622 80833 0.02426 487.534 20095.5 0.85

532367 1957.9 4.0159 85912 0.02445 487.534 19940.3 0.85

527288 2082.6 4.2716 90991 0.02464 487.534 19789.3 0.85

522209 2208.1 4.5292 96070 0.02482 487.534 19640.5 0.85

517130 2334.7 4.7888 101149 0.02501 487.534 19494.4 0.85

512051 2462.2 5.0503 106228 0.02519 487.534 19351.4 0.85

506972 2590.6 5.3137 111306 0.02538 487.534 19211.7 0.85

501893 2719.9 5.579 116385 0.02556 487.534 19075.5 0.85

496815 2850.2 5.8462 121464 0.02573 487.534 18944.4 0.85

493096 2946.1 6.043 125183 0.02586 487.534 18851.6 0.85

ENROUTE CRUISEANALYSIS 31000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

775750 0 0 0 0.01688 498.75 29554.4 0.85

766100 163.8 0.3284 9650 0.01707 498.75 29214.6 0.85

757630 309.1 0.6198 18120 0.01724 498.75 28922.1 0.85

ENROUTE CRUISEANALYSIS 35000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

Page 4
cruise

754999 0 0 0 0.0173 489.956 28324.6 0.85

752602 41.5 0.0848 2397 0.01737 489.956 28209.8 0.85

744840 177.2 0.3617 10159 0.01759 489.956 27855.1 0.85

737077 314.6 0.6421 17922 0.01781 489.956 27517.1 0.85

729315 453.7 0.9259 25685 0.01802 489.956 27186.6 0.85

721552 594.4 1.2132 33447 0.01825 489.956 26853.6 0.85

713790 736.9 1.5041 41210 0.01847 489.956 26527.2 0.85

706027 881.2 1.7984 48972 0.01869 489.956 26210.8 0.85

698264 1027.1 2.0964 56735 0.01891 489.956 25903.8 0.85

690502 1174.8 2.3978 64497 0.01913 489.956 25608.8 0.85

682739 1324.2 2.7026 72260 0.01935 489.956 25322.2 0.85

674977 1475.2 3.0109 80023 0.01957 489.956 25038.3 0.85

667214 1627.9 3.3226 87785 0.01979 489.956 24761.8 0.85

659452 1782.4 3.6378 95548 0.02 489.956 24493 0.85

651689 1938.5 3.9565 103310 0.02022 489.956 24233.4 0.85

643927 2096.3 4.2785 111073 0.02043 489.956 23984.9 0.85

636164 2255.6 4.6037 118835 0.02063 489.956 23745.3 0.85

628401 2416.6 4.9323 126598 0.02084 489.956 23509.9 0.85

620639 2579.2 5.2641 134360 0.02105 489.956 23281.2 0.85

620477 2582.6 5.271 134523 0.02105 489.956 23276.5 0.85

ENROUTE CRUISEANALYSIS 39000 0 (FEET)

WIND ( KNOTS) = 0 DTEMP (DEG C.) = 0

WEIGHT DISTANCE TIME FUEL NMI/LB VELOCITYFUEL FLOWMACH

LB NMI HR LB KTS LB/HR

618279 0 0 0 0.02111 487.534 23098.3 0.85

613629 98.6 0.2022 4650 0.02129 487.534 22903.3 0.85

608550 207.2 0.4249 9729 0.02148 487.534 22695.8 0.85

603471 316.8 0.6497 14808 0.02168 487.534 22491 0.85

598392 427.4 0.8766 19887 0.02188 487.534 22285.1 0.85

593313 539 1.1056 24966 0.02208 487.534 22080.5 0.85

588234 651.7 1.3366 30044 0.02228 487.534 21878.8 0.85

583155 765.3 1.5698 35123 0.02249 487.534 21681.1 0.85

578077 880.1 1.8051 40202 0.02269 487.534 21487.7 0.85

572998 995.8 2.0426 45281 0.02289 487.534 21299.2 0.85

567919 1112.6 2.282 50360 0.02309 487.534 21115.6 0.85

562840 1230.3 2.5236 55439 0.02329 487.534 20936.2 0.85

557761 1349.1 2.7672 60518 0.02349 487.534 20758 0.85

552682 1468.9 3.0129 65597 0.02368 487.534 20584.2 0.85

547603 1589.7 3.2607 70675 0.02388 487.534 20415.9 0.85

542525 1711.5 3.5105 75754 0.02407 487.534 20253.4 0.85

537446 1834.2 3.7622 80833 0.02426 487.534 20095.5 0.85

532367 1957.9 4.0159 85912 0.02445 487.534 19940.3 0.85

Page 5
cruise

527288 2082.6 4.2716 90991 0.02464 487.534 19789.3 0.85

522209 2208.1 4.5292 96070 0.02482 487.534 19640.5 0.85

517130 2334.7 4.7888 101149 0.02501 487.534 19494.4 0.85

512051 2462.2 5.0503 106228 0.02519 487.534 19351.4 0.85

506972 2590.6 5.3137 111306 0.02538 487.534 19211.7 0.85

501893 2719.9 5.579 116385 0.02556 487.534 19075.5 0.85

498769 2800 5.7431 119509 0.02567 487.534 18994.4 0.85

Page 6
climb

24000 24000 0.1263 42 114633 2042 0.6589 9600

26000 26000 0.1436 49 114471 1822 0.6853 9125

28000 28000 0.1631 57.2 114297 1598 0.7131 8679

29855 29855 0.184 66.2 114120 1383 0.74 8289

29855 29855 0.184 66.2 114120 1889 0.74 8289

30000 30000 0.1853 66.7 114110 1871 0.74 8248

32000 32000 0.2046 75.1 113956 1605 0.74 7682

34000 34000 0.2276 85 113787 1322 0.74 7134

35000 35000 0.241 90.7 113693 1173 0.74 6868

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 129082 3694 0.388 16119

2000 2000 0.0023 0.6 129045 3657 0.3914 15950

4000 4000 0.0116 3 128900 3505 0.4056 15290

6000 6000 0.0213 5.6 128754 3353 0.4204 14649

8000 8000 0.0315 8.4 128608 3190 0.436 14004

10000 10000 0.0423 11.4 128461 3016 0.4523 13350

10000 10000 0.0423 11.4 128461 500 0.4523 13350

10162 10162 0.0477 13.1 128389 500 0.5071 13544

10162 10162 0.0477 13.1 128389 3070 0.5071 13542

12000 12000 0.0579 16.4 128253 2895 0.5245 12980

14000 14000 0.0699 20.4 128101 2701 0.5443 12377

16000 16000 0.0827 24.9 127947 2502 0.5651 11750

18000 18000 0.0966 29.9 127788 2296 0.5869 11125

20000 20000 0.1118 35.5 127623 2093 0.6098 10562

22000 22000 0.1286 41.8 127450 1901 0.6338 10082

24000 24000 0.1471 49.1 127268 1708 0.6589 9600

26000 26000 0.1679 57.5 127074 1507 0.6853 9125

28000 28000 0.1918 67.5 126862 1301 0.7131 8679

29855 29855 0.2178 78.7 126641 1094 0.74 8289

29855 29855 0.2178 78.7 126641 1495 0.74 8289

30000 30000 0.2194 79.4 126628 1476 0.74 8248

31000 31000 0.2312 84.5 126532 1349 0.74 7965

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

31000 31000 0 0 125495 1357 0.7449 7990

32000 32000 0.013 5.7 125394 1220 0.745 7705

34000 34000 0.0447 19.4 125159 924 0.7452 7156

35000 35000 0.0647 28 125019 761 0.7454 6891

LARGE AIRPLANE

Page 2
climb

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 571691 4629 0.388 75955

2000 2000 0.0018 0.5 571554 4613 0.3914 75487

4000 4000 0.0091 2.3 571011 4537 0.4056 73623

6000 6000 0.0165 4.3 570471 4425 0.4204 71491

8000 8000 0.0242 6.4 569933 4274 0.436 69018

10000 10000 0.0321 8.6 569394 4114 0.4523 66503

10000 10000 0.0321 8.6 569394 0 0.4523 66503

10000 10000 0.0405 11.4 568823 0 0.5838 69827

10000 10000 0.0405 11.4 568823 4429 0.5838 69827

12000 12000 0.0483 14.3 568293 4170 0.6052 66844

14000 14000 0.0566 17.5 567752 3896 0.6275 63860

16000 16000 0.0654 21.1 567199 3640 0.651 61097

18000 18000 0.0749 25 566633 3403 0.6755 58500

20000 20000 0.0852 29.3 566050 3098 0.7011 55160

22000 22000 0.0962 34.1 565449 2932 0.728 53553

24000 24000 0.1081 39.5 564828 2716 0.756 51555

26000 26000 0.1209 45.4 564179 2466 0.7854 49211

28000 28000 0.1353 52.3 563491 2183 0.8162 46567

30000 30000 0.152 60.5 562740 1847 0.8484 43799

30097 30097 0.1529 61 562701 1828 0.85 43653

30097 30097 0.1529 61 562701 2700 0.85 43653

32000 32000 0.1654 67.2 562178 2397 0.85 40354

34000 34000 0.1804 74.6 561600 2069 0.85 36957

36000 36000 0.1982 83.3 560973 1699 0.85 33491

36089 36089 0.1991 83.8 560944 1681 0.85 33334

36089 36089 0.1991 83.8 560944 1519 0.85 33334

38000 38000 0.2232 95.5 560182 1175 0.85 30422

39000 39000 0.2386 103 559723 994 0.85 29009

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

39000 39000 0 0 510274 1323 0.85 28807

40000 40000 0.0136 6.6 509892 1144 0.85 27464

42000 42000 0.0498 24.3 508954 770 0.85 24874

43000 43000 0.0749 36.5 508348 585 0.85 23669

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 671951 3821 0.4017 76160

2000 2000 0.0022 0.6 671785 3808 0.4052 75734

4000 4000 0.011 2.9 671124 3744 0.4198 73957

6000 6000 0.02 5.4 670466 3640 0.4351 71817

Page 3
climb

8000 8000 0.0294 8.1 669807 3504 0.4512 69356

10000 10000 0.0391 10.9 669146 3359 0.468 66841

10000 10000 0.0391 10.9 669146 0 0.468 66841

10000 10000 0.0498 14.6 668409 0 0.6023 70338

10000 10000 0.0498 14.6 668409 3625 0.6023 70338

12000 12000 0.0594 18.3 667754 3381 0.6242 67182

14000 14000 0.0696 22.4 667082 3141 0.6472 64224

16000 16000 0.0806 26.9 666390 2918 0.6712 61482

18000 18000 0.0925 32 665677 2709 0.6963 58925

20000 20000 0.1054 37.6 664936 2465 0.7226 55941

22000 22000 0.1194 43.9 664165 2304 0.7501 54250

24000 24000 0.1345 50.9 663360 2107 0.7788 52183

26000 26000 0.1513 58.9 662507 1887 0.8089 49818

28000 28000 0.1704 68.4 661583 1621 0.8403 47128

28599 28599 0.1767 71.5 661286 1527 0.85 46266

28599 28599 0.1767 71.5 661286 2255 0.85 46266

30000 30000 0.1876 77 660799 2064 0.85 43826

32000 32000 0.2051 85.7 660063 1759 0.85 40354

34000 34000 0.2262 96.2 659250 1430 0.85 36957

35000 35000 0.2387 102.3 658800 1255 0.85 35304

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

35000 35000 0 0 620477 1500 0.85 35058

36000 36000 0.012 5.8 620069 1301 0.85 33259

36089 36089 0.0131 6.4 620031 1283 0.85 33102

36089 36089 0.0131 6.4 620031 1159 0.85 33102

38000 38000 0.0466 22.7 618978 805 0.85 30211

39000 39000 0.0704 34.3 618279 621 0.85 28807

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

1500 1500 0 0 790626 3130 0.4246 76691

2000 2000 0.0027 0.7 790422 3117 0.4283 76259

4000 4000 0.0135 3.8 789608 3054 0.4437 74464

6000 6000 0.0246 7.1 788793 2956 0.4597 72317

8000 8000 0.0361 10.5 787974 2829 0.4766 69890

10000 10000 0.0482 14.3 787146 2695 0.4943 67394

10000 10000 0.0482 14.3 787146 0 0.4943 67394

10000 10000 0.0616 19.1 786215 0 0.6242 70690

10000 10000 0.0616 19.1 786215 2869 0.6242 70690

12000 12000 0.0737 24 785380 2656 0.6468 67607

14000 14000 0.0868 29.4 784515 2445 0.6704 64672

16000 16000 0.101 35.5 783615 2249 0.6951 61943

Page 4
climb

18000 18000 0.1164 42.3 782679 2092 0.7209 59848

20000 20000 0.1333 49.9 781695 1869 0.7479 56856

22000 22000 0.1519 58.6 780656 1725 0.7761 55074

24000 24000 0.1723 68.4 779554 1551 0.8056 52962

26000 26000 0.1954 79.8 778359 1348 0.8364 50660

26854 26854 0.2064 85.3 777807 1237 0.85 49459

26854 26854 0.2064 85.3 777807 1828 0.85 49459

28000 28000 0.2173 90.9 777280 1682 0.85 47350

30000 30000 0.2391 101.8 776291 1405 0.85 43826

31000 31000 0.2517 108.1 775750 1248 0.85 42064

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

31000 31000 0 0 757630 1352 0.85 41772

32000 32000 0.0132 6.5 757092 1191 0.85 40074

34000 34000 0.0469 23.2 755805 843 0.85 36700

35000 35000 0.0695 34.3 754999 660 0.85 35058

HPR HGEO TIME DIST WEIGHTROC MACH T FF

FT FT HR NM LB FPM LB/HR

35000 35000 0 0 620477 1500 0.85 35058

36000 36000 0.012 5.8 620069 1301 0.85 33259

36089 36089 0.0131 6.4 620031 1283 0.85 33102

36089 36089 0.0131 6.4 620031 1159 0.85 33102

38000 38000 0.0466 22.7 618978 805 0.85 30211

39000 39000 0.0704 34.3 618279 621 0.85 28807

Page 5
Charts-bizjet-med

Bizjet

Medium Range Mission

0

10,000

20,000

30,000

40,000

50,000

60,000

0 1 2 3 4 5 6 7 8

Time (hr)

Altitude (ft)

Pressure Alt

Bizjet

Medium Range Mission

-100

-50

0

50

100

150

0 1 2 3 4 5 6 7 8

Time (hr)

Ambient Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Very Hot 99%

Bizjet

Medium Range Mission

0

5,000

10,000

15,000

20,000

25,000

0 1 2 3 4 5 6 7 8

Time (hr)

Fuel Remaining (lbs)

Fuel Remaining

Main Tank 1 Fuel

Remaining

Main Tank 2 Fuel

Remaining

CWT Fuel Remaining

Bizjet

Medium Range Mission

-60

-40

-20

0

20

40

60

80

100

120

140

0 1 2 3 4 5 6 7 8

Time (hr)

Total Temp (F)

Very Cold 1%

Cool 25%

Average 50%

Warm 75%

Hot 95%

Very Hot 99%

Extremely Hot 99.9%

Airplane Standards (3).xls, Charts-bizjet-med 7/8/98