RELATIVE BENEFIT ASSESSMENT OF FIRE PROTECTION SYSIEM CHANGES 

Ginger Bennett 

Booz-Allen & Hamilton, Inc. 

Dayton, OH 45431 USA 

ABSTRACT 

With tlic sapidly exp;mding variety oi fire protection technologies coinpeling f(is liinitetl RXD budgets. txilitieh, md 

expertise, it has become necessary to develop 21 system bcncfit assessment methodology Cor use in RXD effort\. 

Such a methodology is nccessary 10 compare. rate. and evaluate these compcting technologies in der lo select the 

most proiiiising for further drvclopment. tu assess the potential benefits and cost5 for each. and to develop a riiti(inal 

developnientiil funding profile lor each technology and an overall R&D proyam ah ii whole. The putposc of this 

discussion will be to prrscnt recent findinfs and to discus5 future efforts. 

BACKGROUND 

Aircraft Fire Hazards 

Aircraft have special problems in regard to fires. Aircraft carry munitions that can be initiated by 

a fire. In addition. aircraft also contain large quantities of fuel distributcd in fuel tanks throughout thc aircraft with fuel lines running between these tanks and the engine(s). These facts contribute to three basic types of aircraft firc zones-dry bays. engine nacellcs, and fuel tank ullage. 

Fire-extinguishing systems are used on military and commercial aircraft to protect engine 

nacelles (the region surrounding the exterior of the jet engine case and shrouded by an outer 

cover, and typically ventilated), dry bays (which can include wing lending/trailing edges. landing 

gear, avionics. and weapons bays). and fuel ranks (as an inertant in the fuel tank ullagc). These 

systems are fixed in configuration and activated remotely to totally flood the compartment in 

question with fire extinguishant. Auxiliary power units (APU), which provide ground, supplementary, or emergency power. arc also frequently protected using such systems, either as standalone units or in conjunction with the engine nacelle fire-extinguishing system. 

Fire is either the primary cause or a contributing factor in most cases of loss of aircraft assets. In 

many instances, injuries to personncl and loss of mission capability accompany a fire evcnt. 

Aircraft fires are a significant cost to the Air Forcc. Methods and technologics to mitigate them 

or “design them out” are imperative, not only to save aircraft, but also to save lives and prevent 

property damage. 

Aircraft Dry Rays 

Dry bays are defined as void volumes within the mold line of the aircraft, excluding air inlels, 

engine compartments, and exhaust nozzles. Examples include wing leading edge bays, landing 

gear wheel wells, avionics equipment hays. and weapons bays. Dry bays can include wing 

lcading/trailing edges, landing gear, avionics and weapons bays. and related zones where a 

catastrophic rupture of flammable fluid and an ignition supply. such as from :I ballistic impact. 

can create a sustained fire. Dry bays frequently contain fluid lines (fuel, hydraulic, coolant), 

bleed air ducts, and electrical cables and may contain avionics, flight control actuators. hydraulic 

accumulators. and liquid oxygen dewars. 

Halon Options Tcchnic;il Working Conlcrcncc 27-29 April 19%) 409 
Aircraft Engine NacelledAuxiliary Power Units (APU) 

The engine nacelle is defined as the region surrounding the exterior of the jet engine case, 

shrouded by an outer cover, and typically ventilated. Auxiliary power units (APU) are machinery 

units that provide supplemental, auxiliary, or emergency power to all or some subsystems of the 

aircraft. 

Engine nacelle fire protection systems are designed to protect against events such as ruptured or 

leaking fuel. hydraulic fluid, or oil lines within the nacelle. In these circumstances, flammable 

fluids can leak onto the hot engine case or accessory components and ignite. These systems can 

also protect against the results of catastrophic events such as thrown turbine blades, which can 

instantaneously rupture fuel sources or overheating components and initiate fluid fire scenarios. 

The first step in such cases is to shut down the engine. once the proximity fire detector confirms 

a fire is present, and the pilot is satisfied that a true fire event has occurred. Even with the engine 

shut down and flammable fluid supply turned off, up to a minute or more of fuel and other 

flammable fluids flowing into the fire zone can occur, sometimes under high-pressure, depending 

upon the location and nature of the failure and the capability to remotely arrest the flow near the 

point of damage. Under these conditions, a supply of fuel can be maintained for a lengthy period 

to create robust fire conditions that, left unchecked, can heat and ignite severe metal fires or burn 

through surrounding structure and threaten the welfare of the aircraft, creating fire conditions in 

collateral areas before the fuel is drained. thereby weakening key structures. In addition, impacts 

into the engine nacelle by ballistic projectiles in combat can also create failure conditions and 

resultant fires (provided that the engine case is not penetrated, which could result in catastrophic 

engine failure becoming the more immediate threat). 

APUs are used to provide supplemental, auxiliary, or emergency power to all or some of the 

subsystems of the aircraft, either on the ground or in flight. These units function and generate 

power independently from the normal aircraft engine systems. The power units may be miniature 

turbines or other power generating equipment, but are typically smaller than the normal jet 

engine propulsion systems. These compartments must be protected against potential fires. since 

the possibility of fuel. hydraulic fluid, or oil leakage onto the hot power unit and equipment or 

catastrophic unit failure can create fire scenarios just as in the engine nacelles. For many military 

aircraft, the engine fire protection system is plumbed to be alternatively used in the auxiliary 

power unit compartment, since in most cases the engine fire protection system’s capacity is more 

than adequate for the smaller volume of the APU bay. In some cases, however, the APU compartment may have a larger free volume than an individual engine nacelle or otherwise require a 

greater quantity of extinguishant than the nacelle, so great care must be taken to assure that 

sufficient capacity is designed for either use. APU compartments can be ventilated, so provision 

must be made for dilution of extinguishant by ventilation airflow during discharge. In many 

cases, however, the ventilation system is designed to be closed during discharge, hopefully 

sealing off the compartment. For many military transport and most commercial aircraft, an 

independent fire protection system is designed for a remote APU compartment, which may be 

located within the cabin or cargo section, or in the tail section. These systems must then be 

designed separately from engine nacelle systems. 

Aircraft Fuel Tanks 

Historically, fuel fire and explosion are a major cause of aircraft losses in combat. Data from 

Southeast Asia show over half of the aircraft combat losses involved fuel fires and explosions. 

410 Halon Oplions Technical Working Conlkrence 27-29 April lY9Y 
While other factors might also have contributed to the loss (e.g., pilot killed. loss of control. etc.), 

this fact nonetheless indicates the fuel system is ;I very significant contributor to an aircraft’s 

vulnerability. Therefore, to increase survivability. various techniques are used to reduce the 

vulnerability of the fuel system to this significant threat effect. 

Ullage (the void space above the fuel level in a fuel tank) in aircraft fuel tanks can have a 

potentially explosive fuel-air mixture. If initiated by a combat threat, an explosion can result. 

Halon I301 is used to inert these fuel tanks and prevent this phenomenon from occurring. 

Currently, two USAF aircraft systems use halon for fuel rank inerting: F-I6 and F-l 17. 

Fuel tank explosions are ii result of ullage deflagrations or detonations where the combustion 

overpressure generated exceeds the structural strength of the tank. With large ignition sources, 

cornbustion will occur and overpressures will vary according to the threat level, tank volume, and 

oxygen concentration. If the combustion wave propagates throughout the ullage with near 

stoichiometric fuel/air mixture. a pressure increase of over 100 psig (8 times atmospheric 

pressure) is theoretically possible. The inerting system must provide protection from in-tank 

arcing due to lightning, electrostatic discharge, and combat threats [I]. 

Halon Replacement 

International concern for the apparent depletion of stratospheric ozone has led to agreement to 

eliminate man-made production of ozone-depleting chemicals (ODC). Recent studies have 

shown halons are the worst known ODC per unit mass making it the first chemical family to be 

eliminated. Originally planned to be phased out of production by the year 3000, the production 

of halon was accelerated to January 1994. This now leaves only existing stocks of halon for use 

in essential applications such as aircraft fire and explosion systems. 

The banning of halon production and the search for non-halon firc extinguishing material has 

resulted in a rapid evolution of a wide variety of aircraft fire protection technologies. This has 

produced sizable development programs by government, university, industry. and R&D organizations. These are expected to continue for some time. especially with the advent of the DoD Yyear Next Generation Fire Protection Technology Program (NGP). 

Because of the heavy reliance on halon in the past. halon’s high effectiveness. and the 

“standardized” approach to the design and test of halon systems. there has been little or no 

development of methodologies for evaluating the various competing fire extinguishing 

technologies that may replace halon. 

With the current explosion of fire protection techiiologies competing for limited R&D budgets, 

f. ,icilities, .”’ and expertisc, it has become necessary to develop an R&D assessment methodology to 

compare, rate. and evaluate these competing technologies in order to selcct the most promising 

for further R&D, to assess the potential benefits and costs for each, and to develop a rational 

funding profile for each technology and the R&D program as a whole. 

This project will develop from an understanding of the fire protection state-of-the-art to en 

assessment of modifying individual components to an identification and quantification of cost 

drivers. and finally culminate in a tool with established baselines. This tool will be usable not 

only in its current form, but also as a foundation for ii more comprehensive methodology capable 

of evolving with the fire protection state-of-the-art. 

Halon Oplions Technical Working Conlcrcnce 27-29 April 199‘) 4 I I 
OBJECTIVE 

The primary goal of this program is to develop means to evaluate the relative desirability of 

potential changes to current fire protection systems and/or procedures that would enhance fire 

suppression efficiency. Each stage is designed to be a logical progression to reach this objective. 

The end-goal of this project is to apply the methodology as soon as possible during the technology development process to make sure the technology will be retrofitable and superior to 

currently available solutions. 

OVERVIEW OF PROGRAM 

The prqject comprises several phases. Phase I will determine the positive and negative features 

of the current technologies and practices as uncovered under Project I .a. and divide each system 

into components including, but not limited to the extinguishing agent, storage bottle, distribution 

plumbing, and human operator for nonautomatic systems. Phase Il will identify all the potential 

impacts and interdependencies resulting from modifications to a given component (e.g., hardware, agent) as well as procedural changes. Phase III will identify the cost drivers for making 

modifications to fire protection systems as they impact development. acquisition, certification, 

and deployment; rank these cost drivers in order of magnitude and determine which cost drivers 

to cany forward; and quantify both the recurring and nonrecumng cost drivers. Phase IV will 

entail assembling the complete life cycle cost methodology using Expert Choice, an analytical 

hierarchy process software tool; assessing the risks of formulating conclusions when comparing 

dissimilar technologies when presented with incomplete data, etc.; developing baselines using 

the previously identified near-term solutions, (HFC-125, HFC-227ea, etc.); and identifying 

technology areas with a potential for high payoff for immediate exploitation. 

PLATFORMS UNDER CONSIDERATION 

This task will examine several weapon systems of the different services, including the following: 

US Air Force (F-18, F-16, C-17, C-130, Blackhawk helicopter, and Chinook helicopter); US 

Navy (DDGS 1 [Arleigh Burke] Class-AEGIS Guided Missile Destroyer, LHDl [WASPILHAI 

[TARAWA] Class-Amphibious Helobanding Craft Carriers; and LCAC-Landing Craft Air 

Cushion); and US Army (MI Tank Series, M2, M3 Bradley Personnel Carrier, and M992 

FAASV Ammunition Resupply Vehicle). Originally, Command and Control Centers were to be 

investigated; however, they were eventually omitted from this study. 

CURRENT WORK 

The current work encompasses the analysis of current configurations. the identification and 

ranking of cost drivers, and the acquisition of data for models (Expert Choice, Air Force Materiel 

Command Logistics Support Cost [LSC] model, Operational Requirements-based Casualty 

Assessment [ORCA] model, and the BLUEMAX model). 

Analysis of Current Configurations 

The positive and negative features of the current technologies, possible areas for modification, 

and practices as uncovered under the DoD 9-year Next Generation Fire Protection Technology 

412 Halon Option. Technical Working Conferencc 21-29 April 1999 
Program (NGP) Element I.a., “Development of Modcl Fires from DoD Fire Data,” have been 

determined (due to the recent completion of this effort). This information is being reviewed aiid 

compiled into a usable format. The system information is being broken down into components 

including, but not inclusive to the agent, storagc bottle, distributioii plumbing, and human 

operator for non-automatic systems. Since the goal of the NGP is a retrofitable technology. it is 

not anticipated there will be any extreme deviatiotis froin the types of components found in 

current systems and practiccs. A timeline is being derived for each platfonn under consideration 

beginning with thc estimated fire initiation, detection, extinguishant discharge. and transport 

times. The following criteria are being cmployed when evaluating the method of fire suppression 

to be employed: technology and pcrformancc characteristics, R&D lab and small-scale testing 

required, R&D medium to large-scale testing requircd, suppression effcctivencss (theoretical and 

design). and certification method. 

Task Status 

The purpose of NGP Element I.a., “Development of Model Fires from DoD Fire Data.” was tcharacterize the fires encountered; derive il few model fires to guide NGP research; and identify 

Hnlon 1301 system constraints to guide NGP research. Many factors can have a dramatic effect 

on fire intensity and suppression results. Some of these includc fuel type, flow type and rate. and 

droplct size. Thc intent of this task was to charactcrize and tabulate the nature. frequency, consequences (including personnel injuries), and severity of fires previously and currently attacked 

using Halon 1301. This involved determining the fucl flow characteristics during such fires and 

their impact on suppressant requirements. A small set of representative (model) fires for other 

elements in the Program was constructed. Development of appropriate new technologies 

rcquires knowledge of the fires of concern and the characteristics and limitations of the systems 

thcy will replace or into which they will be retrofitted. The descriptions of the environmcnts of 

the current systems compiled during this program will serve as boundary conditions For the new 

technologies to be developed in subsequent elements of the NGP Program. 

The items queried from the aircraft community (System Program Offices and airframers) as well 

as some generic responses (so 21s not to reveal specific weapon system platform infomation) are 

given below. Generic information requcsted included the number of aircraft, service cycle refill 

(ycars). fire types (pool fires, mist...), and estimated halon usclyeariaircraft, Information (number of fire zones, sizc, volume, free volume, operating conditions, etc.) regarding the fire zone 

was also queried. The fire zone may be dctined as compartments containing flammable materials 

or tlammable fluid lines or tanks, if such compartments also contain sources of ignition [2]. 

Thc existing extinguishant information was also of interest. This information included type, 

number of systems, extinguisher trigger mode (automatic or pilot activated [manual]). extinguisher volume (in’), size of extinguishant container (in, in, in). storage compartment for 

extinguishant bottle (in, in, in), free volume in storage compartment (ft’). normal chargc and 

pressure of extinguisher container (psi), maximum extinguisher container pressure (psi), 

extiiiguishcr container percent filled (5%). extinguisher container orientation (upright with valves 

at bottom. etc.), cxtinguishcr containcr weight without halon (Ih), halon wt (Ih), extinguisher 

container location (insideloutside fire zone). strategy for use (detect fire. select bottle, select 

engine, pull “T” handle), number of shots, suppression success fraction (based on historical data, 

i.e.. combat and peacetime data), extinguisher system manufacturer. type and degree of rcstriction on the use of alternative fluids. and range of expected operating temperatures for the bottle 

and the plumbing (OF). 

Halon Option, Technical Working Conlcrcncc 31-29 April I WU 4 13 
An item, which presents an opportunity for redesign with the advent of new extinguishants, is the 

distribution system. Therefore, the following information was requested to obtain specific information on this system: extinguisher dispersion method, extinguisher discharge rate (CFM), 

distribution system plumbing, inner diameter (in), length (in), shape (bends, elbows) (system 

complexity), number and nature of nozzles/pipe terminations, access of current distribution 

plumbing for retrofit, access and available space for additional distribution plumbing or nozzle 

modification, and evidence of halon distribution characteristics (from certification tests). 

The optimization of the fire suppression delivery system is imperative in making retrofitable 

technologies that can meet the requirements of the weapon systems. Extensive DoD efforts to 

identify optimal near-term halon alternative technologies have shown that, even if available, 

currently tested alternatives have sizable (2-3X) weight and volume penalties. Their application 

to fielded weapon systems (whose service lives are being extended) could require expending 

large amounts of funding and time for system redesign and reconfiguration at a time of defense 

budget reductions and downsizing. Experiments (such as recent F/A- I8EF tests. which have 

allowed comparable amounts of HFC-125 to be used to replace the Halon 1301 system) have 

shown that significantly enhanced agent dispersion can result from improvements in the 

suppressant delivery system [3]. 

The effect of making modifications to agent distribution systems may significantly impact how 

less effective agents may be utilized. The impact of this retrofit is one of the items being 

evaluated in this current effort. The effect of access to the distribution system and bottles is also 

important. This may temper the ability to retrofit the aircraft due to the incurred costs of 

modifying the aircraft. Due to the less efficient agents, more bottles or larger bottles may be 

necessary. This survey queried the community for the specific platforms on their ability to 

accommodate more bottles or larger bottles. The costs of retrofitting a current aircraft design to 

incorporate a different distribution system or the addition or enlargement of the agent bottles, 

may incur significant costs. This may not be possible and/or may not be preferred. 

Identification and Ranking of Cost Drivers 

Cost drivers for making modifications to fire protection systems as they impact development, 

acquisition, certification, and deployment-in essence the costs to field the modifications-are 

being identified. These cost drivers are being ranked in order of magnitude. The panel members 

will determine which cost drivers to carry forward into the Cost Driver Quantification stage. 

When identifying cost drivers, the following assessments are being performed: Technical 

Assessment, Cost Assessment, Time Assessment, and Risk Assessment. 

Task Status 

Specific cost information (development, certification, deployment, operating and support, etc.) 

has been difficult information to obtain. Most contacts report that this type of information is not 

readily accessible and therefore difficult to compile. To date, one method to obtain cost information that is compiled in a centralized database is to contact the Air Force Materiel Command (HQ 

AFMC). They manage a database called the Weapon System Cost Retrieval System (WSCRS). 

This database is sorted by National Stock Number (NSN). If the NSNs are known for the fire 

suppression system components, these can be tracked in the system and the cost information 

(procurement and repair) can be found. Points of Contact have been obtained in all three services 

for similar organizations such as the one in HQ AFMC. These NSNs are being requested from 

4 14 Halon Options Technical Working Conference 27-29 April 1Y9Y 
the Equipment Specialists ofthe Air Logistics Centers (ALC) (or the Service Equivalent). If this 

information is not within the ALC, the System Program Office (SPO) or potentially the airframer 

may need to be contacted (especially for cost information on the distribution systems). This was 

ia breakthrough in obtaining cost information for the various components. Other cost information 

such as the modification costs will need to be obtained from the responsible organizations (SPO). 

Acquisition of Data for Models 

ered. Prior to their requisite use. data pertinent to the operation of these models in subsequent 

stages of this program are being compiled. A brief description of the models to be used follows. 

Expert Choice 

Expert Choicc is a commercial-off-the-shelf (COTS) decision support software package that can 

be used for strategic planning, program analysis, and optimizing resource allocation. It is a 

multicriteria decision support software tool that uses the analytic hierarchy process (AHP) as the 

decision making methodology. AHP arranges the components of a problem into an hierarchical 

structure similar to ii fmiily tree. Complex decisions are decomposed into a series of simple 

comparisons and rankings, and a decision is synthesized from these results. This structure allows 

the decision making process to be thoroughly documented for future reference. Multiple ohjectives, alternatives, and criteria can be defined by the user. Expert Choice can integrate subjective 

judgments with numerical data in developing the decision model. Sensitivity analysis capabilities are provided in order to investigate the relative importance of various assumptions or the 

impact of various alternatives. 

Air Force Materiel Command Logistics Support Cost (LSC) Model 

Life-cycle costs of fire suppression technologies can be addressed using various cost models such 

as the Air Force Materiel Command Logistics Support Cost (LSC) Model. The development of :I 

replacement aircraft fire-extinguishing technology will generate a requirement for the weapon 

system program directors to address life-cycle costs. Life-cycle costs include all the costs associated with a vehicle or subsystem over its useful lifetime, including its purchase price. For an 

aircraft fire suppression system, these costs include maintenance manpower, consumable agents, 

parts. retrofit costs. training, development. depot maintenance, support equipment, flisht qualification. and initial production. Determining retrofit costs is also required for DoD budget inputs. 

AFR 173-13 requires that a cost analysis be performed for all modifications that affect the life 

cycle cost of the system being modified or that will affect the operating and support costs to any 

appropriation over the expected remaining system service life. 

Operational Requirements-Based Casualty Assessment (ORCA) Software System 

The Operational Requirements-based Casualty Assessment (ORCA) model translates data on the 

toxicity and compatibility of new suppressants with humans and their principal degradation 

products Lo the ability of personnel to perform their key functions and the subsequent impact on 

platform overall mission effectiveness. A methodology is being developed using compatibility 

data for the existing fire suppression technologies (HFC- 125. dry chemicals. xrosols, water mist. 

etc.) as a starting point until the new fire technologies and their corresponding compatibility data 

are identified. Probabilistic scenarios will be gcnerated for the applicable weapon systems as 

well as for maintenance personnel exposed to an agent, using the interaction of the agent and its 

decomposition with humans. As the compatibility data for the new suppre nts are made availTo, cass~st , .. . in developing the methodology and baselines, several existing models are being considH:ilr,n Options Technic:d Working Cont'ercncc 21-29 April 1949 4 15 
able during the NGP program, they would be implemented into the ORCA model and similar 

analyses would be performed as with the existing agents. One product of this proposed project is 

the determination of acceptable exposure levels for different missions and operating conditions, 

which can accommodate personnel evacuation or length of exposure. This will establish the 

upper permissible concentration thresholds in which the suppressants must demonstrate successful fire-extinguishing performance. 

BLUEMAX 

Particular to the NGP program will be the use of BLUEMAX to estimate the cost of the additional fuel consumption caused by the weight of the fire suppression system on an aircraft as well as 

the weight scale-up factor reflecting the additional hardware that must be included because of the 

fire suppression system, e.g., mounting brackets, fasteners, tubing, etc. 

Task Status 

Expert Choice and Air Force Materiel Command Logistics Support Cost (LSC) Model 

The identification of cost information necessary to access the total costs associated with combat 

vehicle fire-extinguishing systems has been completed. At the weapon system level these costs 

include systems certification, toxicity, test equipment, certification methodology, maintenance, 

support, manufacturing, and logistics. This information will be used in the LSC and Expert 

Choice models. The following discussion describes the components that comprise the various 

cost elements. The lists below are not exhaustive ones. 

(a) Items that affect maintenance costs-unscheduled servicing, time change (item. frequency, 

hours), test equipment, deployment gear, HazMat gear, special storage site costs, special 

transportation equipment costs. initial spares and repair parts, crew size, mean time to repair, 

mean time between failure, number of programmed flying/operating hours, peculiar support 

equipment, usage rate, costs of items within system, repair level probability (base or depot), 

weight, shipping costs, packing costs, cleanup procedures and equipment, special handling 

equipment, disposal costs, servicing equipment and expectant life, corrosion, inspections, 

skill levels, and consumable items (sealants, gaskets, safety wire, etc.). 

(b) Factors that may affect acquisition costs-system engineering/program management, configuration control, technical data, TOs, modification of weapon system, human factors design 

considerations, spares support, NDI methods. repair tools, repair techniques/development of 

battle damage, safety of flight issues, software support, tolerances, initial tooling, modification strategy, legal costs, weapon crew, emergency procedures, etc. 

(c) Items that affect operation and support costs-fuel penalty, special logistics (shipping containers, special trailers, new storage facilities) packaging protection levels, airlift requirements, highway standards, safety, fragile, sensitive, or hazardous material requirements, 

clarify mobility, deployability, and transportability requirements, requirements for special 

permits, equipment performance, mobility, transportability, service life, and user operational 

test and evaluation, transportability criteria, etc. 

(d) Factors that may affect engineering and manufacturing development costs-prime mission 

equipment (structure, integration, assembly, test and checkout, propulsion, installed equipment (hal.dwdre/Software), system and application software (where applicable), system test 

and evaluation, system engineering/program management (flyaway cost), support equipment 

(peculiar and common), training, data. initial spares and repair parts, operational/site activa416 Halon Option.: Tcchnical Working Conference 27-29 April 199') 
tion. industrial facilities, in-house. contingency/risk factor, etc. Other cost items include 

performance of Trades Studies, acquisition of SAF/AQ halon waivers. disposal costs, etc. 

ORCA 

The latest version of ORCA has been compiled and linked. Thc required data format needed for 

the toxicity input file have been requested from the Army Research Laboratory. 

The following arc scveral DoD applications for the ORCA model: 

(a) Armored vehiclcs have total-flood fire extinguishing systems in them. If a fire occurs and 

the extinguishing system is activated, crewmembers are exposed lo the clean agent. the byproducts of combustion, the clean agent plus the byproducts of combustion, and the decomposition of the new agent in the fire environmenl. The crew needs to be able IO either continue performing the mission. or discontinue the mission entirely and drive the vehicle away 

or at least be able to evacuate. These individuals could be exposed to fire (resulting in 

burns), obscuration of the eyes due to the nature of the extinguishant (dry powder. particulate 

[mist, fog]), toxic gases, particulates that could get into the lungs and effect breathing, 

cardiac sensitizers, disorientation, impeded decision makins ability, degraded visibility, just 

LO mention a few examples. ORCA could be used to cvaluate these insults and their effects 

on the individual’s ability to escape or continue to perform his mission. 

(b) Helicopters have portable Halon 1301 extinguishers for use in the cabin and engine fire 

extinguishing systems. Fixed engine systems could also allow extinguishant to bleed into 

the cabin space duc to its close proximity. The effects of the agent and its decomposition 

would need to be evaluated due to the peak performance required for helicopter control. 

(c) Cargo hays, such as the C-SA cargo bay. have a total-tlood extinzuishing systems. Often 

therc are crewmembers in this area who would experience exposure to the agent and its 

decomposition. 

(d) The Navy has total-flood systems in the engine and machine rooms onbourd ships. The 

effects of the decomposed agent and its mixing with the byproducts of the fire would affect 

the engine room operators and subscquent firefighters sent in to verify the extinguishment. 

(e) Maintenance personnel could be exposed particularly to the clean agent, during its installation, replacemcnt, demilitarization, banking. recycling, and destruction. 

BLUEMAX 

Efforts are underway to obtain the aircraft data files for BLUEMAX for the C-I7 and F/A-I8. 

The aircraft scenario files for the F- I6 and C-I 30 have been restored and tested. BLUEMAX is 

only valid for fixed wing aircraft, therefore, no BLUEMAX data for the H-60 and CH-47 will be 

obtained. 

FUTURE WORK 

Future work will encompass the identification of potential impacts resulting from modifications, 

the quantification of cost drivers. and the formulation of a methodology and devclopment of 

baselines. 
Identification of Potential Impacts Resulting from Modifications 

The potential impacts resulting from modifications to a given component (eg, hardware, agent) 

as well as procedural changes will be identified. For instance, given a change in agent, what will 

be the impact(s) to field the system? Special attention will be given to the interdependency of 

various components (e.g., agent efficiency, plumbing diameter, etc.). For instance, a less 

efficient agent may be able to use existing plumbing but require a larger bottle; however, to 

discharge the contents of a larger volume in the required time, larger diameter distribution tubes 

may be required. The potential impacts will be determined and potential interactions identified. 

Quantification of Cost Drivers 

This task will involve the quantification of both the recurring and nonrecurring cost drivers. 

Recurring costs, e.g., maintenance, weight, will be tied to operational hours. System improvements will appear as decreases in operational costs per hour and detriments will appear as 

increases in operational costs. Nonrecurring costs include initial acquisition, retrofit, etc. 

Methodology Formulation and Development of Baselines 

This will entail assembling the complete life cycle cost methodology using Expert Choice, an 

analytical hierarchy process software tool; assessing the risks of formulating conclusions when 

comparing dissimilar technologies when presented with incomplete data, etc.; developing baselines using the previously identified near-term solutions, (HFC-I 25, HFC-227ed, etc.); and 

identifying technology areas with a potential for high payoff for immediate exploitation. 

The baselines developed in this phase will be important to the application of methodology, but, 

they will not be made integral. By keeping the baselines distinct from the methodology, new 

baselines can be easily established in the future as fire protection technologies evolve. These 

baselines will offer a goal that emerging technologies must surpass at a given stage prior to 

proceeding further. This will help assure that NGP achieves its goal of replacing existing halon 

installations with minimum impact on the weapon systems. 

SUMMARY 

Extensive DoD efforts to identify optimal near-term halon alternative technologies have shown 

that, even if available, currently tested alternatives have sizable (2-3X) weight and volume 

penalties. Their application to fielded weapon systems (whose service lives are being extended) 

could require expending large amounts of funding and time for system redesign and reconfiguration at a time of defense budget reductions and downsizing. The optimization of the fire suppression system is imperative in making retrofitable technologies that can meet the requirements of 

the weapon systems. 

The outcome of this effort is a methodology for, and execution of, life-cycle cost assessments of 

Halon 1301 replacement technologies relative to the current best available options, so that platform managers can compare unlike alternatives and make the best selection for their purpose. 

418 Halon Options Technical Working Confcrence 27-29 April l9Y9 
ACKNOWLEDGMENTS 

The author would like to acknowledge the Air Force Rcsearch Laboratory Safety and 

Survivahility Branch, Air Forcc Materiel Command, C-17, C-130. and F-16 SPOs, Naval 

Aviation Systems, Naval Sea Systems Command. Army Research Laboratory, US Army Tank - 

Automotive aiid Armaments Command, and San Antonio Air Logistics Center for their 

assislance in obtaining the requisite information. It is realized that this information has been 

dirficult to obtain and your cfforts are appreciated. 

REFERENCES 

1 . Fires Exper-icwrtl urd Hulori 1301 Sirppression Sy.stems iri Cirl-rent Wcwpon Systc~s 

Pltrffi,rm.s, SURVIAC-TR-99-XX, Mar. 1999 (in press). 

2. Estiriguisliirig S~sten7. Fire, Aircrqfi. Hi:.h-Rufc.-Di.sc.hur.Se Type*. Instullutioi? und Test of: 

MIL-E-22285, 7 May 1997 (Approved for public release; distribution is unlimited). 

3. "Statement of Need for FY2000 Next Generation Fire Suppression Technology Prozram 

(NGP) New Starts," NGP Wehsite (hltp://www.dtic.mil/ngp/).