Exemption No. 10193

UNITED STATES OF AMERICA

DEPARTMENT OF TRANSPORT ATION

FEDERAL AVIATION ADMINISTRATION

RENTON, WASHINGTON 98057-3356

In the mattcr of the petition of

The Boeing Company

for an exemption from § 25.1535 of Title

14, Code of Federal Regulations, as

specified in Appendix K, § K25.1.4(a)(3)

Regulatory Docket No. FAA-2010-0496

GRANT OF EXEMPTION

By letter BDCO-IO-03739, dated Seplember 7,2010, Mr. Jordan B. Zundell, Lead Project

Administrator-Production and Retrofit Projects, The Boeing Company, P.O. Box 3707, MC

67-LR, Seattle, WA 98124-2207, petitioned the Federal Aviation Administration (FAA) for an

exemption from the requirements of § 25.1535 of Title 14, Code of Federal Regulations

(14 CFR) for its Model 777-200, 777-200LR, 777-300ER, and 777F airplanes, as the regulation

applies to low-fuel alelting for approval of these mode~s for extended operations (ETOPS)

beyond 180 minutes. This exemption, if granted, would permit the Boeing Company a period of

time to develop and incorporate design changes for their low-fuel-alerting system into the Model

777 ai.rplanes.

The petitioner requests relief from the following regulation:

Section 25.1535, as specified in Appendix K, § K25.1.4(a)(3) - Low-fuel alerting.

K25.1.4(a)(3) - An alert must be displayed to the flightcrew when the quantity of fuel available

to the engines falls below the level required to fly to the destination. The alert must be given

when there is enough fuel remaining to safely complete a diversion. This alert must account for

abnormal fuel management or transfer between tanks, and possible loss of fuel. This paragraph

does not apply to airplanes with a required flight engi.neer.
The petitioner supports its request with the following information:

This section quotes the relevant infonnation from the petitioner's request. The complete petition

is available at the Department of Transportation's Federal Docket Management System, on the

Intemet at http://regulations.gov, in Docket No. FAA-201O-0496.

Discussion

Title 14 CFR, Part 25, Appendix K, Section K25.1.4(a)(J) states that, "An alert must

be displayed to the flight crew when the quantity offllel available to the engines falls

below the level required to fly to the destination. The alert must be given when there

is enough fuel remaining to safely complete a diversion. This alert must account for

abnormal fuel management or transfer between tanks, and possible loss of fuel. This

paragraph does not apply to airplanes with a required flight engineer."

The above rule ostensibly grew out of the Airbus incident in the Azores where the

crew was unaware ofa massive fuel leak and had to glide the airplane to the runway.

Boeing and FAA SACO have conducted numerous meetings about how to

demonstrate model 777 compliance with the above rule. Boeing believes that

appropriate architectural changes to AIMS, with correspondingly revised check list

operations, comply with the rule, and Boeing is on record to accede the incorporation

afthe AIMS changes. It is estimated that the incorporation of these changes will take

approximately five years.

These AI:MS changes for low fuel alerting 'fill be implemented along with other

AIMS changes not related ta extended ETOPS, and those other changes will take

approximately two to three years to be designed, tested and certified, plus an

additional one year for in-service incorporation by airline operators.

These discussions between Boeing and FAA precipitated the decision byF AA to

clarify their position via Issue Paper.

While these discussions and negotiations between Boeing and FAA have been

proceeding, EASA has granted ETOPS certification far operation beyond 180

minutes. The EASA NPA 2008-01 for extended ETOPS contains a different standard

with regards to low fuel alerting than FAA Jule K25.1.4(a)(3), and Boeing's current

,

architecture is likely compliant with the EA,SA eRr without further changes. This

puts Boeing FAA certified aircraft: at a signi:ficant disadvantage in the marketplace.

Granting of the exemption will allow FAA certified aircraft to operate beyond

180/207 minutes, thereby leveling the comp1etitiveness ofF AA-certified aircraft to

that of EASA-certified aircraft.

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Justification

Existing ETOPS CeTtificatioD Basis

ETOPS certification of current 777 models is based on 777 ETOPS special conditions

(25-ANM-84/84A) and ETOPS Policy Letter no. 20-1 (EPL-20-1).

Effect on Safety

Dunng the exemption period, Boeing will make changes to the existing 777 "Low

Fuel Alerting" architecture to become fully compliant with K25.1.4(a)(3). While this

change activity is proceeding, it is important to take the following factors into

consideration:

The current 777 "Low Fuel Alerting" architecture contains a Fuel Imbalance and Fuel

Disagree EICAS Advisory message. Both Fuel Disagree and Fuel Imbalance have

associated crew-checklist items for leak determination. Also, the FMC provides an

alert for Insufficient Fuel. These messages, in addition to the crew fuel-monitoring

procedures, listed in AC 120-42B, Section 304, provide significant crew awareness.

Boeing has already made a change to the Fuel Disagree Message as a result of an

internal cross model safety assessment based on the A330 Azores incident. AJthough

no deficiencies were noted in the Boeing designs, it was decided to elevate the Fuel

Disagree to an EICAS Advisory message from an FMC scratch pad message as a

safety enhancement.

The operational approval for 330 minutes will be limited to areas south of the equator,

including the Indian Ocean, South Pacific, South Atlantic, and South Pole region

where operations are expected to be thin and grow slowly. Therefore, exposure to

beyond 180 minutes will be very small compared to the historical database and

continuing operations at 180 minutes.

Boeing will study the planned enhancements to comply with K25.1.4(a)(3), in

conjunction with existing guidelines and crew procedures, to determine if Boeing can

supplement existing guidelines and crew procedures so as to mitigate the impacts due

to the enhancements not being available during the exemption period.

In light of the above justifications, Boeing seeks a time-limited exemption from

§ K15.1.4(a)(3).

Public Interest

This exemption is essential for Boeing's airline customers flying FAAvcertified

aircraft to compete with airline customers flying EASA-certified aircraft and to

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reduce operational costs on longer-range flights. One airline stated that the success of

its long-term business plan is dependent on ETOPS beyond 180/207 minutes.

This reduction in operational costs will also benefit the flying public economically

and environmentally. The economic benefit~ are derived fTomreduced ticket prices

and reduced personal travel times due to the more direct flight routes. The reduction

in travel times is especially important to the business traveler segment of the flying

public.

The enviromnental benefit is derived from the operator's ability to shorten flight

tracks around many regions around the world or natural disasters like volcanic

eruptions. The longer flight tracks required for 180-minutes ETOPS result in large

increases in fuel bum and/or large reductions in revenue payload. The number of

airlines requesting the extended ETOPS certification is significant, which only

exacerbates the overall environmental impact. One airline stated that ETOPS beyond

180/207 is an important and significant enabler for the airline to reach its

environmental goal to reduce CO2 emissions. This exemption would represent a

significant step toward reducing costs to the operators and thereby its customers, as

well as serving to protect the environment from unnecessary fuel consumption.

Request

Boeing hereby petitions for an exemption from 14 CFR K25.1.4(a)(3) as it relates to

low fuel alerting on Boeing Model 777-200, 777-200LR, 777-300ER, and 777F

airplanes. This exemption is requested to al~ow Boeing to certify the 777 models for

FAA operators wishing to operate ETOPS missions beyond 180/207 minutes per the

mles outlined in Appendix K of Title 14 CFR Part 25.

Boeing Response to FAA Letter dated June 10, 2010.

FAA Question 1:

What specific design changes will you be making to comply with section

K25.1.4(a)(3)?

Boeing reply:

Boeing will answer this question in response to Issue Paper EE-1.

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Supplemental Boeing reply:

Boeing transmitted a description of the specific changes it will make to the Model 777

design to comply with § K25.1.4(a)(3) in letter number BDCO-1O-04796 dated

November 12, 2010. These changes are identified in the following table.

Current 777 Functionality Design Changes for Compliance to K25.1.4(a)(3)

Insufficient Fuel Message

FMC Scratch Pad Message Add EICAS Advisory Message INSUFFICIENT FUEL on Active

INSUFFICIENT FUEL Route.

Retain FMC Scratch Pad Message INSUFFICIENT FUEL on Mod

Route.

No associated checklist Add QRH Checklist for INSUFFICIENT FUEL.

None Add a color change to the Total Fuel Quantity indication on the

prima'Y EICAS and the expanded fuel indications synoptic page:

Turn "amber" while the message is active.

Fuel Disgree Message

FUEL DISAGREE EICAS Revise the trigger threshold for FUEL DISAGREE EICAS Advisory

Advisory Message Message to a lower value.

QRH Checklist No change to QRH Checklist.

FMC fuel predictions use Revise FMC logic to allow the Flight Crew to switch between FQIS

Calculated Fuel as the default. Totalizer Fuel and Calculated Fuel, at any time, regardless of the

A one-time selection to FQIS status of FUEL DISAGREE message.

Totalizer Fuel is available to the

Flight Crew after the FUEL

DISAGREE is issued.

A manual fuel entry at engine Remove inhibit of FUEL DISAGREE due 10 a manuallvel entry

start inhibits FUEL DISAGREE before engine start. Add functionality to delete the manual entry total

message. fuel quantity and synchronize the CALC fuel with the FQIS totalizer

fuel quantity value, at engine start.

Imbalance Message No change.

Fuel Qty Low No change.

Fuel Flow Eng l,R

None Add EICAS Advisory Message FUEL FLOW ENG L,R for detection of fuel

flow anomalies downstream of the flow meters.

None Add FUEL FLOW ENG L.R QRH Checklist.

None Add functionality to automatically display the secondary engine indications

when the message FUEL FLOW ENG L,R is active.

None Add functionality to automatically display the expanded fuel indications when

!he message FUEL FLOW ENG L,R is active.

FAA Question 2:

How many operators (and airplanes) want to enter such operations immediately after

greater-than-180-minutes ETOPS approval is granted? How many of those are U.S.

operators?

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Boeing reply:

The number of operators, to date, that have expressed interest in entering the 180-

minutes-plus ETOPS operations, immediately after approval is granted, is eight. Of

those eight, three are U.S. operators. The estimated number of airplanes involved is

behveen thirty and thirty-five.

J?AA Question 3:

How many operators would be operating in.greater-than-I80-minute ETOPS during

the exemption period?

FAA Question 4:

How many airplanes would be operating in greater-than-180-minute ETOPS during

the exemption period?

Boeing reply:

Our current analysis sunnises that the 777 will generate historic growth in the

Southern- and mid.Pacific~region routes over the next five years. The extrapolation

assumes that the trends seen in the North Atlantic and North Pacific will continue in

the Southern Oceans once the 777 is certified for beyond 180/207.

The analysis assumes a total of 780 flights in 2009 ramping up to 6,500 B777 flights

in 2015 for the Southern and mid-Pacific oceans. It is assumed that these flights will

utilize greater than 180/207 as it becomes available. The estimated fleet size that

corresponds to 6,500 flights per year is appr:oximately 70 to 100 airplanes by 2015.

That translates mto a fleet increase of62-plus airplanes.

Furthermore, other regions, like the polar region, are expected to need greater-than1801207 ETOPS capability for increased flexibility, depending on the availability of

alternates. It is expected that a U.S. carrier operating in the polar region would utilize

240-minute ETOPS approximately 50 times a year. A separate marketing analysis has

projected a fleet size of 13 airplanes for operations that provide increased flexibility

with 240-minute ETOPS.

Consideration must also be given to whether the Western and Southern Pacific routes

are saturated. Approval of greater-than-180Jminute ETOPS and its attendant

increased profit potential is certain to attract additional carriers into that market

sector.

The above dissertation translates into the following numbers for the 5-year exemption

period:

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Additional airplanes: 70 - 100

Additional operators: 12 - 15

Boeing is unable to predict at this time how many of those would be U.S. earners.

FAA Question 5:

What will be the schedule for incorporating the design changes, particularly for the

operators who will he operating in greater-than-180-minute ETOPS during an

exemption period?

Boeing reply:

Boeing requests a 5-year exemption period based on the following timeline for

events:

a) 1 year fOfIssue Paper EE-l Closure and Finn Design on software change

b) 2-3 years for software development and certification (standard flow)

c) 1 year for operator incorporation after software change is certified

Federal Register publication

Although the petitioner initially requested that action on its petition not be delayed for

publication in the Federal Register, the FAA found that the petition, if granted, would set a

precedent. Therefore, to allow an opportunity for the public to comment on the petition, a

summary of it was published in the Federal Register on September 23,2010 (75 FR 184). The

FAA received comments from three sources. Comments from V Australia Airline and Air New

Zealand fully support Boeing's exemption request. The Air Line Pilots Association, International

(ALP A) suggests both a shorter timeframe than that which Boeing requests for complying with

low-fuel-messaging regulations, and that" ... the petition should be more derinite in outlining

[Boeing's] plan to ultimately comply with the cited FAR." This commcnter feels that five years

to implement a software change is unrealistically long and exposes aircraft, passengers, and

crews to avoidable risk during that time.

The FAA's analysis

Boeing states in their petition for exemption that appropriate architectural changes to the

Airplane Infonnation Management System (A.llvfS),with correspondingly revised check list

operations, would comply with the ETOPS low fuel alert requirement, and that Boeing is on

record to accede to the incorporatlon of the AlMS changes. Boeing provides no explanation in

its petition why the company would not be able to comply with this requirement before type

certification. This implies that a commitment to making a compliant design change in the future

is all the justification necessary to obtain an exemption. To counter this implication, additional

conlext is necessary.

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The ETOPS low fuel alert requirement came into existence in amendment 25-120 to part 25,

which became effective on February IS, 2007. This requirement was not a part of the previous

ETOPS policy or practice that was codified in this amendment to part 25, but came about as a

result of service experience that indicated such a requirement was necessary to ensure continued

safe long-range operations. At the time the FAA deliberated on this requirement~ we and Boeing

believed the Model 777 desih'l1would comply without further change. It was not until after

several engine fuel leaks occurred on the Model 777 in late 2008 and early 2009 that the FAA

came to realize that the existing 777 alerting system was not sufficient to confmn the existence

ofa fuel leak so that the flight crew could take appropriate corrective action. Therefore, it would

not comply with the new low fuel alert requirement after all.

In two of these events, the flight crew detected a fuel imbalance and diverted, but did not shut

down the leaking engine. In each case, the airplane continued to lose fuel overboard during the

diversion and the fuel leak was not confirmed until after the airplane landed safely. By the time

Boeing committed to making design changes to the Model 777 airplane to comply with the

ETOPSlow fuel alert requirement, they were within six months of the time when the company

sought type design approval for greater than l8D-minute ETOPS. Since the identification of the

non-compliance with the low fuel alert requirement camc relatively late in the 777 certification

program for greater than ISO-minute ETOPS and Boeing had committed to making appropriate

design changes, the FAA felt that an exemption for an appropriate period of time for Boeing to

design and develop a compliant design could be found to be in the public interest.

The FAA has evaluated Boeing's petition for exemption from the low-fuel alert required by

14 CFR § 25.1535, as specified in Appendix K, § K.25.1.4(a)(3). We considered whether or not

granting such a tinle-limited exemption would be in the public interest, and if doing so would not

adversely affect safety or provide a level of safety at least equal to that provided by the rule from

which Boeing seeks exemption. If those 1\vo conditions could be met, we also looked into what

would be an appropriate period of time for Boeing to design, test, and incorporate design changes

into the 777 fleet that will comply with this airworthiness requirement, taking the resulting level

of safety into consideration.

ALPA stated that the petition should be more definite in outlining the plan to ultimately comply

with the cited regulation. The FAA received more defulitive information about Boeing's plan to

comply with the low-fuel alert requirement in letter number BDCO-IO-04796, dated November

12, 2010. We have placed this letter in the public docket for this exemption petition. While we

have not yet found that the specific set of changes to the Model 777 design proposed by Boeing

will comply with the rule, we accept that such changes will be a part ofa showing of compliance.

Public Interest:

The FAA agrees that a reduction in operational costs associated with being able to operate on

more direct airline routes will also benefit the flying public both economically and

environmentally. We agree that the economic benefits are derived from reduced ticket prices and

reduced personal travel times due to the more direct flight routes. We also agree that the

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reduction in travel times is especially important to business travelers for whom time is a valuable

commodity.

Boeing points out that more direct flights would also be a significant factor in reaching airline

environmental goals for reducing CO2 emissions. Any benefit of a time-limited exemption on

CO2 emissions would be dependent on the period of time that an airplane could be operated on

shorter ETOPS routes before compliant design changes are incorporated. We don't share

Boeing's view that this would be a significant benefit because any reduction in CO2 emissions

during cruise compared to flying a longer route for the same city pair, to stay within existing 180-

minute ETOPS authority, is small compared to the emi~sions during takeoff and climb, which

would not be affected by an exemption.

Also, these public benefits would be realized eventually after a compliant design is incorporated

iDto the 777 fleet even without an exemption. Therefore, the remaining question then is whether

it is in the public interest that these benefits occur now, rather than after Boeing incorporates a

compliant design into the 777 fleet at the end of an exemption period. Boeing states that this

exemption would be essential for Boeing's airline customers flying FAA-certified aircraft to

compete with airline customers flying aircraft that have already received approval rrom other

authorities for ETOPS beyond 180 minutes. We agree that delaying approval of the 777 for

ETOPS beyond 180 minutes, while waIting for a comphant low-fuel alert design, could create a

real economic disadvantage to those operators of the 777 airplane who are in direct competition

with aircraft serving the same city pairs. This could result in those operators choosing to buy

those other aIrcraft to remain competitive.

Boeing mentions in its petition that the European Aviatlon Safety Agency (EASA) has approved

other aircraft for ETOPS beyond 180 minutes based on a different European safety standard than

the FAA has adopted. While the FAA has not yet made a specific finding on these aircraft for

compliance with § K25.1.4(a)(3), we have reason to believe that they would not comply with the

marc stringent FAA standard. As such, it would not be in the public interest to create a

competitive environment that could result in a largcr population of non-compliant airplanes in

service than would occur if an exemption were granted. Any non~compliant 777 airplanes that

enter greater than 180-minute ETOPS during an exemption period would have to be modified

with a compliant design when it becomes available as a condition for the exemption.

Level of Safety During the Exemption Peliod:

We agree with ALPA that operating passenger aircraft with a non-compliant design would

expose passengers and crews to increased risk during the exemption period. We believe that such

risk could be mitigated with compensating factors during the exemption period and that the

effectiveness of such compensating factors should be in direct proportion with the length of time

that they would be in effect. However, this risk is also mitigated by existing features in the 777

design that will be a part of the complete set oftligbt-deck alerts Boeing will use to comply with

the low-fuel alert requirement. So, the additional risk to be mitigated by compensating ractors is

limited to the specific conditions that the Boeing proposed design changes will address.

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Service experience has shown that that the current 777 design and operational procedures have

not adequately confirmed the existence of some fuel leaks. Even though the airplane landed

safely following each occurrence, the flightcrews did not take specific action to stop the loss of

fuel because of a lack of such confmnation, Delays in confirming and taking corrective action for

fuel leaks would have a much more significant effect on safety the farther away an airplane is

from a place to land. While existing 777 design features provide flightRdeck information that a

flightcrew could use to discover and take corrective action for fuel loss, diversion times beyond

180 minutes result in less margin for delays in such discovery before the loss of fuel becomes

critical.

The design features Boeing is proposing for compliance with the low-fuel alert requirement

include several flightcrew alerts with associated operating procedures that are intended to

improve flightcrcw a\vareness and identifIcation of the source of fuel loss, or higher-thanplanned fuel consumption. The most significant changes to the 777 design and flightcrew

operating procedures are intended to detect fuel leaks downstream of the engine-fuel now meters.

Such leaks have been a significant source of fuel loss in service and are currently only detectable

with a Flight Management Computer (FMC) INSUFFICIENT FUEL scratch-pad message. It is

displayed when the predicted quantity of fuel on board the airplane, upon arrival at the

destination, is less than the planned reserves. The current FMC message is not in the flightcrew's

nonnal field of view. Boeing is proposing to raise flightcrew awareness of the INSUFFICIENT

FUEL alert by displaying it as an EICAS advisory message. A new alert that will more directly

detect fuel leaks downstream of the engine-fuel flow meter will be a FUEL FLOW ENG L,R

Engine Indicating and Crew Alerting System (EICAS) advisory message. Boeing did not indicate

what logic would trigger this message, only that it would detect anomalies downstream of the

flow meters. Other design changes Boeing proposes primarily address improvements in the

current FUEL DISAGREE EICAS message. Tllis message is displayed when the fuel quantity

indicating system (FQIS)Rmeasured totalizer fuel quantity and the FMC calculated-total-fuel

quantity di ffers by more than a threshold amount. One of these improvements is to reduce the

triggering threshold to a lower value so that fue1leaks upstream of the engine-fuel flow meter

will be detected earlier in the flight.

The FAA evaluated several options for compensating factors that could be applied until a

compliant low-fuel alert design is incorporated into the 777 fleet. These options focused

primarily 011 reducing the risk of fuel leaks downstream of the engine-fuel flow meter, which are

not adequately addressed in the current 777 design. Although the proposed changes in the FUEL

DJSAGREE EICAS message will improve detection of fuel leaks upstream of the engine-fuel

flow meters, the cUlTentdesign will detect these types of fuel loss. Also, after fuel in the center

fuel tank is consumed, a fuel leak for any cause would result in a main fuel-tank imbalance

EICAS message. The flightcrew procedure for this message asks the crew to detennine if the

imbalance is caused by a fuel leak before opening the fuel-crossfeed valve to balance the tanks.

The FAA-evaluated options are:

Option I: Carry five percent additional fuel reserves above the ETOPS fuel reserves determined

under 14 CFR 121.646(b). The additional fuel reserves would allow more time for a flightcrew to

detect and take corrective action for fuel loss before it becomes critical. The downside of option

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1 is that carrying the additional fuel reserves increases takeoff weight for a given flight, which

requires higher engine fuel consumption to carry that weight, and negates some of the economic

benefit of being able to operate on the more direct, greater~than-180-minute ETOPS routes

between city pairs. Also, carrying additional fuel does not provide a direct means of detecting

fuel loss.

Option 2: Require flightcrew recording of engine-fuel flow rate for each engine once every 30

minutes during ETOPS flights, including recording the difference in the engine-fuel flow rate

between the two engines. If the recorded difference in engine-fuel flow rate rate between the two

engines changes by 500 pounds per hour or marc between two recording checkpoints, initiate the

fuel-leak checklist procedure. This procedure would provide a direct means of detecting a fuel

leak downstream of the engine-fuel flow meter. The SOO-pound-per-hour, engine-fuel-flow-rate

difference threshold, for going to the fuel-leak checklist procedure, would allow crews to catch

most slow fuel leaks before they have a chance to grow into large leaks. A 3D-minute recording

interval limits the amount of fuel that could be lost before a flightcrew becomes aware of a large

leak.

Option 3: Require periodic flightcrew recording of the FQIS-measured totalizer fuel quantity, the

calculated total fuel quantity from the flight-management computer, and the difference from the

planned-mission fuel quantity at that point in the flight. The existing FUEL DISAGREE EICAS

message would detect large differences between totalizer and calculated fuel quantities due to

fuel loss upstream of the engine-fuel flow meters, which may occur before such a leak would be

detected by periodic fuel-quantity checks. So such a comparison would be useful to detect

slower-rate leaks earlier in the flight. For leaks downstream of the engine-fuel flow meter, only

the comparison of the measured fuel quantity with planned-mission fuel at that point in the flight

would detect sucb a leak. It is a standard operating procedure, on oceanic flights, for airline

flightcrews to monitor total fuel onboard and compare it with planned-mission fuel quantity. We

do not see that this option really provides a compensating factor for the design features Boeing

proposes for compliance with the ETOPS low-fuel alert requirement unless these checks are done

more frequently than current practice. The 2001 Air Transat A330 flightcrew monitored fuel

quantity using such a procedure. The onJy fuel check n::quired by the standard procedure Air

Transit used, during the tirneframe that resulted in the A330 fuel exhaustion, occurred at a point

where the difference between measured and plamled total fuel quantity was within 1%.

Conducting fuel-quantity checks at the same frequency as recording engine-fuel £low rates in

option 2 could identify fuel loss upstream of the engine-fuel flow meters before it becomes

critical. In addition, conducting the engine-fuel flow-rate check of option 2, in conjunction with a

comparison of totalizer and calculated fuel, would make a comparison of total fuel quantity and

plalll1cd-missJOn fuel unnecessary because there could be no difference in these values that would

not also be detected by the two other comparisons.

Boeing estimates that between 30 and 35 airplanes would be used in greater-than-180-minute

ETOPS initially growing to between 70 and 100 airplanes after five years. Although the FAA

does not accept operational procedures alone in lieu o['a flight-deck alert for showing compliance

with the ETOPS low-fuel alert requirement, the FAA considers that the combination of options 2

and 3 procedures accomplished at 3D-minute intervals during the ETOPS portion of each flight

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would lower the risk of fuel exhaustion to an acceptable level for this limited number of airplanes

during the exemption period.

Exemption Period:

The FAA is concerned, as is ALPA, about the 5 years Boeing states are required to design, test,

and incorporate compliant design changes into the 777 fleet. Boeing states, in their response to

our request for additional information in support of their petition for exemption, that they need

one year to complete firm design of the softv..'arechange, two to three years for software

development and certification using the standard flow times, and one year for incorporation.

Boeing's response letter to the FAA was dated June 10,2010. Six months have elapsed since the

date of the letter and Boeing has now proposed specific design changes for showing compliance

with the low fuel alert requirement. So, we do not believe it will take a full year from the date of

the issuance of an exemption to complete firm design. Since the proposed design changes are

necessary t.obring the 777 airplane into compl1ance witb the minimum airworthiness standard. [or

ETOPS beyond 180 minutes, we believe that the time to develop and certify the software should

be closer to the shorter two-year stahdard flow time from Boeing's development timeline. Also,

after the software is certified, loading it into each airplane should require only a short time and

could be accomplished during an ovemight stop at an airport where the operator has a

maintenance facility. It should not be a major burden for an operator to schedule incorporation of

the software change into those airplanes of their fleet used on greater-than-180-minute routes.

Therefore, the FAA believes that the entire projected fleet of 70 to 100 airplanes could get the

software updates within one month after final certification.

Shortening Boeing's requested exemption period by the six months that have passed since their

original design completion estimate, using the shorter two~year span for software development

and certification, plus the 11 months we do not believe are necessary for incorporation of the

final~design change, results in a reduction in the total flow time by two years and five months;

from the five years in Boeing's petition. The Model 777 airplane has been in service for over

fifteen years without a fuel exhaustion accident, even in light of the recent iil~service history.

Boeing and the engine manufacturer have taken corrective actions to address the cause of the fuel

leaks in those earlier occurrences and no more fuel leaks have occurred since those actions were

taken. The compensating factors identified above will reduce the risk of Wldetected fuel loss

during an exemption period by providing a manual me~ns for performing the functions of the

intended design changes. Therefore, rounding up to the nearest whole year, we have determined

that a time-limited exemption oftlrree years would allow sufficient time for Boeing to design and

implement a compliant low~fuel alert design into the affected 777 ETOPS fleet while

maintaining an acceptable low risk of fuel exhaustion.

The FAA's decision

In consideration ofthe foregoing, 1 find that a grant of exemption is in the public interest.

Therefore, pursuant to the authority contained in 49 U.S.c. 40113 and 44701, delegated to me by

the Administrator, Boeing is hereby granted an exemption from 14 CFR 25.1535, as specified in

Appendix K, K25.1.4(a)(3), for a low fuel alert. The exemption is granted to the extent necessary

12
to allow Boeing to design, test, and incorporate design changes into the 777 fleet that will comply

with this airworthiness requirement.

This exemption is subject to the following condition(s);

1. At the time of type-design approval of the Model 777 for ETOPS beyond ISO-minutes, the

Configuration, Maintenance, and Procedures (eMP) docwnent, required by § K25.1.6 of

Appendix K to 14 CFR part 25, must contain a configuration item requiring incorporation of

,

a low-fuel alert that complies with § K25.1.4(a)(3) by a date no latcr than January 11, 2014.

lfthe date oftype-design approval occurs after this date, the CMP must require the compliant

low-fuel alert design as a condition for ETOPS beyond 180 minutes.

2. The airplane flight manual must contain required flightcrew operating procedures to be in

effect during the exemption period for each ETOPS flight on routes that extend beyond 180-

minutc diversion times, or 207 -minute diversion times on North Pacific routes if approved on

a case-by-case basis. These proccdures must contain the following elements:

a. Record the following once every 30 minutes during the ETOPS portion of each flight.

1. Engine-fuel flow rate for each engine

11. Totalizer fuel quantity (from FQlS)

111. Calculated fuel quantity (from FMC)

b. Record the difference in engine-fuel flow rate between the left and right engines at

each recording intervaL If the recorded difference in engine-fuel flow rate between

engines changes by 500 pounds per hour between recording intervals, initiate the fuelleak checklist procedure.

c. Compare totalizer and calculated fuel quantities. If totalizer fuel quantity is less than

calculated fuel quantity, initiate the fuel-leak checklist procedure.

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3. Boeing must develop a comprehensive compliance plan and schedule, supporting full

compliance with the low-fuel-alert requirements of 14 CFR 25.1535, as specificd in

Appendix K, K25.1.4(a)(3), to be presented to the IfAA Boeing Aviation Safety Oversight

Office (BASOO) by March 31,2011. Tbereafter, Boeing must submit, to tbe BASOO, a

status report every three months identifying all actions completed to date as well as those that

remain outstanding. The report must demonstrate Boeing's progressive performance and

accomplishments indicating their projected success in meeting both the schedule and

conditions of the exemption.

Issued in Renlon Washington, on JAN11 2011 ?~E.~

Jeffrey Duvcn

Acting Manager, Transport Airplane Directorate

Aircraft Certification Service

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