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Aircraft fires are a significant cost to the Air Force. Methods and technologies to mitigate them
or “design them out" are imperative, not only to save aircraft, but also to save lives and prevent
property damage.

The goal of the Next Generation Fire Suppression Technology Program (NGP) is to develop and
demonstrate retrofitable, economically feasible, environmentally-acceptable, and user-safe
processes, techniques, and fluids that meet the operational requirements currently satislicd by
Halon 1301 systems in aircraft.

There are a large number of contributing factors that must be considered when deciding which
fire suppression system to select for a new platform or whether to retrofit the fire suppression
system on a legacy platform. These include both objective cost factors and subjective value
factors. Accordingly, the NGP has developed a methadology to quantify a fire suppression
technology by its total, life cycle cost and tn enable superimposing on this a subjective value
system. The methodology determines the net cost of the fire suppression system: the cost of the
system (which is a function of system size/weight) minus the cost savings provided by the
system (which are a function of extinguishant effectiveness and result in aircraft saved).

The example used in developing the methodology is a comparison of an existing halon 1301
system and a system of equivalent and altered performance to halon 1301 using an off-the-shelf-
alternative, HFC-125. This methodology was developed to be applicable to both legacy
platforms (for decision makers who must consider retrofit costs for existing platforms) and future
platforms (for decision makers currently designing new platforms).

This methodology has been used to examine the cosls of Ilalon 1301 and HFC-125 for aircraft
engine nacelle applications for example cargo, fighter, and rotary-wing aircraft. It is currently
being adapted and used to examine the costs of Halon 1301 and HFC-125 for aircraft dry bay
applications for example fighter and rotary-wing aircraft and engine nacelle applications for
unmanned aircraft,

Based on the studies performed to date, it appears that the benefit of having cither fire
suppression system substantially outweighs its cost, and the difference in total cost of the two
systems is modest compared to the total cost of owning and operating the aircrafi.

ACKNOWLEDGEMENTS

This research is part of the Department of Defense's Next Generation Fire Suppression
Technology Program, funded by the Dob Strategic Environmental Research and Development
Program under DSS-W contract number SP0700-96-D-4000. The CO'TR for this effort is Mr.
Martin L. Lentz (46h TW/OGM/OL-AC).

The author would like to acknowledge the following organizations and individuals for their
assistance with this project.

« C-17 System Program Office — 1.1. Josh Bohnart, Capt. Brian Godfrey, and Mr. Daniel
Hamblin


FIGHTER AIRCRAFT

For fighter aircraft, the cost of ownership for the legacy Halon 1301 system is $11.2M and for a
legacy HIFC-125 system ranges from $15.7 to $17.8M. The estimated fire cos! is $258M. The
estimated cost savings are between $154.8 and $206.3M. The estimated net cost for the Halon
1301 system ranges from $-143.5M to $-195.1M. The estimated net cost for the HFC-125
system ranges from $-136.9M to $-190,6M.

Using the fighter aircraft fire suppression system cost and cost savings information, the
following conclusions were reached:
¢ Lven if the fighter aircraft fire suppression system only saved scven percent of the
aircraft asscis it was designed to protect, the benefil (assets saved) would still be
greater than the cost of the fire suppression system.
© Using a conservative value of 60 percent fire suppression system effectiveness, a
system cost of up to $282K per aircraft could be justified. Note that the current as
well as forccasl fire suppression system costs per aircraft are an order of magnitude

less than this value. ‘This valuc is a breakpoint between system cost and benefit.

For fighter aircraft, the cost of ownership for the future Halon 1301 system is $14.4M and for a
future HFC-125 system ranges from $15.8 to $18.0M. The estimated fire cost is $260.8M. The
estimated cost savings are between $156.5 and $208.7M. The estimated net cost for the Halon
1301 system ranges from $-142.1 to $ 194.2M. The estimated net cost for the HFC-125 system
ranges from $-138.5M to $-192.9M.

Using the fighter aircraft fire suppression sysicm cost and cost savings information, the
following conclusions were reached:

* Even if the fighter aircraft fire suppression system only saved seven percent of the
aircrafl assets it was designed to protect, the benefit (assets saved) would still be
greater than the cost of the fire suppression system.

¢ Using a conservative value of 60 percent fire suppression system effectivencss, a
system cost of up to $28SK per aircraft could be justified. Note that the current as
well as forecast fire suppression system costs per aircraft are an order of magnitude

less than this value. This value is a breakpoint between system cost and benefit.


COST SAVINGS

Aircraft fires are a significant cost to the Department of Defense. Methods and technologies to
mitigate them or "design them out" are imperative, nol only to save aircraft, but also to save lives
and prevent property damage.

In a previous study (d4nnual Fire Protection Cost Model), the historical and projected costs duc
to fire were determined. By combining the components which comprise the costs of peacetime
aircraft losses due to fire, a resulting historical cost (over a 30 year period) of approximately
$9.271 billion was obtained, mcasured in 1995 dollars; for the costs of combat aircraft losses due
to fire, approximately $5.878 billion ($95), based primarily on Southeast Asia experience was
incurred; for the costs of utilizing aircraft fire protection, approximately $315.651 million ($95)
was experienced. Thus, the total historical costs of fire to the U.S. Air Force over the 1966 to
1995 time period was estimated to be $15.465 billion ($95). The total projected costs of fire to
the U.S. Air Force over the 1996 to 2025 time period was estimated to he $15.990 billion ($96).
A net present valuc of over $119 million was projected to be the net benctfit of fire suppression
systems over the next 30 years. [4]

COSTS OF CURRENT/PROPOSED S

TEMS FOR VARIOUS AIRCRAFT TYPES

This effort developed a methodology to determine total system costs, cost savings incurred, and
het cost of an aviation fire protection system. This methodology was developed for systems with
equivalent and varied performance of Halon 1301 to optimize benefit per system weight and
cost. The methodology has been developed for engine nacelle applications for representative
cargo, fighter, and rotary wing aircraft. The methodology is being developed for dry bay
applications for representative fighter and rotary wing aircraft and engine nacelle applications for
representative unmanned aircraft. The results of these efforts are given below.

CARGO AIRCRAFT

For cargo aircraft, the cost of ownership for the legacy Halon 1301 system is $25M and for a
legucy HFC-125 system ranges from $35 to $41M. The estimated fire cost is $204M. ‘The
cslimated cost savings are between $122M and $163M. The estimated net cost for the Halon
1301 system ranges from $ 97M to $-138M. The estimated net cost for the HFC-125 system
ranges from $-81M to $-129M.

For cargo aircraft, the cost of ownership for the future Halon 1301 system is $36M and for a
future HFC-£25 system ranges from $35 to $44M. Thc estimated fire cost is $226M. ‘The
estimated cost savings are between $136 and $181M. The estimated net cost for the Halon 1301
system ranges from $-99 to $ 144M. The estimated net cost for the HI'C-125 system ranges
from $—-91M to $-146M,

The results of this effort are detailed in SURVIAC TR-00-006, “Cost Analysis of Fire
Suppression Systems For Cargo Aircraft”, M.L. Kolleck, M.V. Bennett, and K.L. Mercer,
Technical Report, Booz Allen Hamilton, Dayton, Ohio, January 2002. [5]


The results of this effort are detailed in SURVIAC TR-02-007, “Cost Analysis of Fire
Suppression Systems For Rotary-Wing Aircraft”, M.L. Kolleck, M.V. Bennett, and K.L. Mercer,
Technical Report, Booz Allen Hamilton, Dayton, Ohio, April 2002. [7]

VARIED PERFORMANCE

Using the methodology previously developed, modifications were made to the performance of
the cargo and fighter fire suppression systems by utilizing data from the Factor of Safety (FOS)
study performed during Phase II! of the Halon Replacement Program for Aviation. These
suppression system weights and corresponding effectiveness were correlated to the cargo and
fighter aircraft platforms.

Tor cargo aircraft, the net cost change per single percent change in cxtinguishing effectiveness
(Le, 91 percent successful vs. 90 percent field success) of the fire system was approximatcly $-
2.0M. For fighter aircraft, the net cost change per single percent change in extinguishing
effectiveness of the fire system was approximately $-2.5M. These cstimates showed that
additional investment in optimizing fire suppression system performance pays off im assets
saved,

Due to the lack of FOS data, it is recommended that a test program be developed to provide
better refinement of the existing FOS data and to reaffirm the hypothesis that the optimal
effectiveness will provide the most dividends (cost savings).

The results of this effort are detailed in SURVIAC TR-01-006, “Cost Analysis of Fire
Suppression Systems Methodology Using Altered Fire Suppression Performance”, M.L. Kolleck,
M.V. Bennett, and K.L, Mercer, Technical Report, Booz Allen Ilamilton, Dayton, Ohio, January
2002. [8]

REMAINING PLATFORMS

Using the methodology previously developed, cost analyses are being developed for dry bay
applications for representative fighter and rotary wing aircraft and engine nacelle applications for
representative unmanned aircraft. These studies are currently underway and the results were not
available at the time of this conference. System data are currently being collected to determine
the sizing constraints of the system. Technical and cost information are being collected from the
various representative platforms. Once these data arrive, the required mass for a Halon 1301
equivalent and varied performance system will be determined. The cost element structure will
be populated which will determine the total system cost. The cost savings will be established.
Once both the system costs and cost savings are determined, the net costs can be ascertained.
Finally, the breakeven point between system effectiveness and cost will be determined.

CONCLUSIONS/SUMMARY

Fire is either the primary cause or a contributing factor in most cases of loss of aircraft assets. In
many instances, injurics to personnel and loss of mission capability accompany a fire event.


COST ANALYSIS OF FIRE SUPPRESSION SYSTEMS

J Michael Bennett Mathias L. Kolleck
460G/OGM/OL-AC Booz Allen Hamilton
2700 D Street Bldg. 1661 4141 Colonel Glenn Highway, Suite 131,
Wright Patterson AFB, OH 45433-7605 Dayton, Ohio USA 45431
Tel: (937) 255-6302 x217, Fax: (937) 255-2237 Tel: (937) 431-2700; Fax: (937) 431-2721
e-mail: Joseph. Bennett@wpafb.af. mil e-mail: kolleck_matt@bah.com
ABSTRACT

The objective of this effort was to perform a comparative cost analysis for Halon 1301 and IIFC-
125 fire protection systems.

This effort developed a methodology to determine total system costs, cost savings incurred, and
net cost of an aviation fire protection system. This methodology was developed for systems with
equivalent and varied performance of Halon 1301 to optimize benefit per system weight and
cost. The methodology has been developed for cngine nacelle applications for representative
cargo, fighter, and rotary wing aircraft. The methodology is being developed for dry bay
applications for representative fighter and rotary wing aircraft and engine nacelle applications for
representative unmanned aircraft.

Based on the studies performed to date, il appears that the benefit of having either fire protection
system substantially outwcighs ils cost, and the difference in total cost of the two systems is
modest compared to the total cost of owning and operating the aircraft.

BACKGROUND

All three services and their respective platforms have special problems in regard to fires. Each
carries munitions, which can be imitiated by a fire. In addition, each also contains large
quantities of fucl distributed in fuel tanks throughout the platform with fuel lines running
between these tanks and the engine(s).

NEXT GENERATION FIRE SUPPRESSION 1

HNOLOGY PROGRAM (NGP)

The goal of the Next Generation Fire Suppression ‘lechnalogy Program (NGP) is to develop and
écmonstrate retrofitable, economically feasible, environmentally-acceplable, and user-safe
processes, techniques, and fluids that meet the operational requirements currently satisfied by
Halon 1301 systems in aircraft. he results will be specifically applicable to fielded weapon
systems, and will provide dual-use fire suppression technologics for preserving both life and
operational assets. [1]

AIRCRAFT FIRES

In most cases, fire is either the primary cause or a contributing factor of loss of aircraft assets. In
many instances, injuries to personnel and loss of mission capability accompany a fire event.


No

NAWCAD (F/A-18 E/F)— Mr. Greg Drohat

NAVAIR (Lakehurst) — Mr. Bill Leach, Mr. Marco ‘Tedeschi, Mr. Don Bein

NAVAIR (China Lake) -- Mr. Joe Manchor

Comanche Program Manager’s Office — Mr. Scott Silies, Mr. Todd Miller, Mr. Glenn Wolf
Pacific Scientific — Mr. Bill Meserve

Walter Kidde Aerospace — Mr. Terry Simpson

DuPont — Mr, Daniel W. Moore

AFMC LSO/SGISA - Ms. Shelia Huis

WPAFB ASRF — Mr. Neil Blevins

REFERENCES

. Next-Generation Fire Suppression Technology: Strategy for A National Program,

Department of Defense, Office of the Director, Defense Research and Engineering, July
1996.

"Fires Experienced and IIalon 1301 Fire Suppression Systems In Current Weapon Systems",
United States Air Force - Air Force Research Laboratory - Survivability and Safety Branch,
Booz*Allen & Hamilton Inc., United States Army - Army Research Laboratory, United
States Navy - Naval Research Laboratory, and National Institute Of Standards and
Technology - Fire Science Division, July 1999.

"The Impact of Ilalon Replacement On Aircraft Engine Bay Fire Protection System Design",
G. Roberts, G. Doria, and T. Breeden, Northrop Grumman Corporation, Presented at the
HALON Options Technical Working Conference, Alouquerque, NM, April 27 - 29, 1999.
"Assessing The Cost Impact Of Fire To The U.S. Air Force", ML. Kolleck and J.M. Bennett,
Presented at the International Aircraft ire and Cabin Safety Research Conference, Atlantic
City, NJ, November 16-20, 1998.

. SURVIAC TR-00-006, “Cost Analysis of Fire Suppression Systems For Cargo Aircraft”,

MLL. Kolleck, M.V. Bennett, and K.L. Mercer, Technical Report, Booz Allen Hamilton,
Dayton, Ohio, January 2002.

SURVIAC TR-01-005, “Cost Analysis of Fire Suppression Systems For Fighter Aircraft”,
MLL. Kolleck, M.V. Bennett, and K.L. Mercer, Technical Report, Booz Allen Hamilton,
Dayton, Ohio, January 2002.

SURVIAC TR-02-007, “Cost Analysis of Fire Suppression Systems For Rotary-Wing
Aircraft”, M.L. Kolleck, M.V. Bennett, and K.L. Mercer, Technical Report, Booz Allen
Hamilton, Dayton, Ohio, April 2002.

SURVIAC TR-01-006, “Cost Analysis of Fire Suppression Systems Methodology Using
Altered Fire Suppression Performance”, M.L. Kolleck, M.V. Bennett, and K.L. Mercer,
Technical Report, Booz Allen Hamilton, Dayton, Ohio, January 2002.


The results of this effort arc detailed in SURVIAC TR-01-005, “Cost Analysis of Fire
Suppression Systems For Fighter Aircraft”, M.L. Kolleck, M.V. Bennett, and K.L. Mercer,
Technical Report, Booz Allen Hamilton, Dayton, Ohio, January 2002. [6]

ROTARY-WING AIRCRAFT

For rotary-wing aircraft, the cost of ownership [or the legacy Halon 1301 system is $33.4M and
is $45.3M for a legacy HFC-125 system. The estimated fire cost is $620.2M. The estimated
cost savings are between $372.1 and $462.7M. The estimated net cost for the Halon 1301
system ranges from $—338.7M to $-462,.7M. The estimated net cost for the HFC-125 system
ranges from $-326.8M to $-450.9M.

Using the rotary-wing aircraft fire suppression system cost and cost savings information, the
following conclusions were reached:

« Even if the rotary-wing aircraft fire suppression system only saved eight percent of
the aircraft asscts il was designed to protect, the benefit (assets saved) would still be
greater than the cost of the fire suppression system.

« Using a conservative value of 60 percent fire suppression system effectiveness, a
system cost of up to $307K per aircraft could be justified. Note that the current as
well as forecast fire suppression system costs per aircraft are an order of magnitude

less than this value, This value is a breakpoint between system cost and benefit.

For rotary-wing aircraft, the cost of ownership for the future Jalon 1301 system is $40.1M and is
$42.2M for a legacy HFC-125 system. The cslimated fire cost is $631.2M. The estimated cost
savings are between $378.7 and $505.0M. The estimated net cost for the Halon 1301 system
ranges from $—338.6M to $464.8M. The estimated net cost for the HFC-125 system ranges
from $ 336.5M to $-462.7M.

Using the rotary-wing ‘aircraft fire suppression system cost and cost savings information, the
following conclusions were reached:

e Even if the rotary-wing aircraft fire suppression system only saved seven percent of
the aircraft asscts il was designed to protect, the benefit (assets saved) would still be
greater than the cost of the fire suppression system.

¢ Using a conservative valuc of 60 percent fire suppression system effectiveness, a
system cost of up to $312K per aircraft could be justified. Note that the current as
well as forecast fire suppression system costs per aircraft are an order of magnitude

less than this value. This value js a breakpoint between system cost and benefit.


80 percent success rate, The Annual Fire Protection Cost Model (described previously in this
paper) postulated that future aircraft losses due to fire incidents were a function of the total
number of flight hours (FH) for this period. An historical relationship between fire costs and
flight hours was established. The resulting average fire costs per flight hour (in FY 2000 dollars)
was $62.85 per flight hour.

COST ANALYSIS

The life-cycle cost of a system includes the acquisition, operation, and maintenance over the life
of the system. The HFC-125 system is reusable/rechargeable. ‘The Pressure vessels must be
hydrostatically tested periodically and the explosive initiators used in the design must be
changed periodically due to the limited propellant life. Support equipment and facilities required
to service these units add to the life-cycle cust. Costs associated with actual system utilization
are generally low because of the infrequent need to use the system, although the rate of
inadvertent discharge in some older aircraft may be significant. The life-cycle cost of a system
can be heavily impacted by the potential for increased weight that may result from incorporation
of a nonozone-depleting fire extinguishing system. [3]

Costs estimated in this effort would be incurred in the research, development, test and evaluation
(RDT&E), procurement, and operations and maintenance (O&M) phases of an acquisition.
RDT&E costs deal with all costs required to develop the fire suppression technology into a
deployable system. Procurement (also called initial or nonrecurring) costs include those
associated with the purchase of the fire suppression system (and associated hardware) and
suppressant. O&M costs are broad and far-reaching. Included in this category are those costs
associated with program management support and life-cycle sustainment management.

COST ELEMENT STRUCTURE DATA DEVELOPMENT
This fire suppression system's detailed cost element structure (CES) is based on the DoD $000.4-

M and MIL-HDBK-881 CES. It was customized for this particular system and approach. The
resulting CES used in this methodology is given in Table 1.


System characterization was necessary to fully understand and appreciate the system cost
information. This was accomplished for both a Halon 1301 and HFC-125 system. Information
which assisted in characterizing these systems included technical manuals, HFC-125 Design
Guide, and assistance from the program managers. Additional system characterization data
included the number of bottles, bottles size, activation, number of shots, and information on the
distribution system. Space limitation, bottle/plumbing accessibility, and modification potential
data were compiled.

System cost information was developed utilizing the data contained in logistics databases that
contains part numbers, suppliers, and other logistical information specifically for the Service of
interest, and various traditional costing factors that are used by government and industry.
Additional data came from the program managers. Fire suppression system and chemical
manufacturers were contacted for cost information, Maintenance cosls were based on the
maintenance manhour per flight hour. Military personnel costs were based on authorizations.

The following figure shows a standard process used to determine fire suppression system costs.

tonal Experts
“Analysis of Allematives
«Preferred Solution

Life-Cycle
Cost Estimating

Process
tem Seluctinn system Ground Rules Data Coloesion Application of Uncertainty Cost Estimate
ee oo ee | & [—P]& Methodology} po! Estimating Ppp) an Documentation|
Planning Assucpsions Selection Techniques Risk Evaluation & Delivery
-Tochnical Specialists Functional Deserption —« tnsgratin + Similne Systems Cost Estimating « Esimating Vncerntcs «Ground Rules
+ Program Analysss Mission Requirements» Schedule = Teohnology Projections Kelavunslps * Technical Risk * Methodology
Cost Analyts = Development Scenano + Acusiion Satogy -Cast/Teahalcl Data Souress Paarvetive + Soho + Dala Soura
SLCCESchedule + Technical Charasteistis - Test Plan “Contractor Inter Data + Araluguus Techniques» Progreen * Updates
+ Finalve cos + Program Charavtensties «MIL-STD-RBIB ——« Comparitive Analisis Engtngoring Methods» Sensvity Analysis
proposal + Teel Baseline FOBNCAIG O88 Hak + Ops & Support Fstimate
Tis! proposed "System Dessiption Time Phasing
deliverables lotion
Pudge Profiles
tangles
WRSICES

Figure 1. Standard Life Cycle Cost Estimating Process.

The cost savings for the life cycle period of interest in this study were estimated by using the
traditional success rate for existing engine halon systems, the estimated fire costs per flight hour,
and the number of flight hours for the aircraft of interest, Field experience of existing engine
halon systems on current aircraft, depending on the platform, shows that the systems have a 60 to


Aircraft fires are a significant cost to the Department of Defense. Methods and technologies to
mitigate them or "design them out" are imperative, not only to save aircraft, but also to save lives
and prevent property damage.

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), and dry bays (which can include wing leading/trailing edges,
landing gear, avionics, and weapons bays). These systems are fixed in configuration and
activated remotely to totally flood the compartment in question with fire extinguishant.
Auxiliary power units (APUs), which provide ground, supplementary or emergency power, are
also frequently protected using such systems, either as stand-alone units or in conjunction with
the engine nacelle fire-extinguishing system.

Engine nacelle fire protection systems arc designed to protect against events such as ruptured or
leaking fuel, hydraulic fluid, or oil lines within the nacelle. In these circumstances, flammable
fluid can leak onto the hol engine case or accessory components and ignite. These systems also
protect against catastrophic cvents such as thrown lurbine blades that instantaneously rupture
fuel sourees or overhcaling componcnts that can iniliale fuel fire scenarios. The two most
common types of fire hazard in the engine nacelle are a direct consequence of the means of fuel
delivery, i¢., either a spray fire or a pool fire. An additional fire hazard associated with the
aircraft engine nacelle is that even after extinguishment is achieved, a strong potential exists for
reignition of the fire from hot surfaces. Hot surface reignition remains a threat as long as fuel
vapor and air can come in contact with sufficiently hot surfaces. Suppression of the hot surface
reignition fire hazard in the engine nacelle requires an additional amount of agent over that
required for flame extinguishment in order to maintain extinguishment until the hot surfaces
cool.

Dry bays are defined as void volumes within the mold line of the aircraft, excluding air inlets,
engine compartments, and exhaust nozzles. Examples include wing leading edge hays, landing
gear wheel wells, avionics equipment bays, and weapons bays. Dry bays frequently contain fluid
lines, bleed air ducts, and electrical cables and may contain avionics, flight control actuators,
hydraulic accumulators and liquid oxygen dewars. A fire in a dry bay typically requires a
rupture of the flammable fluid components and the generation of an ignition source. For this
reason, it is assumed that this scenario is created when a ballistic projectile impacts a dry bay in
flight, rupturing fuel system components and generating tremendous ignition energy. Although
this is the assumed primary initiation means, other initiation sources, such as overheated,
shorting electrical circuits in avionics bays, some other form of impact (ie., bird strike), or
burning stored munition propellants, can also be responsible in rare instances. [2]

METHODOLOGY

A methodology was developed to determine the net cost of the firc suppression system. This
methodology incorporates the cost of the system, which is a (unction of system size/weight, and
the cost savings provided by the system, which are a function of extinguishant effectiveness and
the resultant aircraft saved. The net cost is the cost of the system minus the cost savings.