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oo MAET MAET MAET

RETROFIT OPPORTUNITY FOR HFC-125

IN AIRCRAFT ENGINE SYSTEMS

Presented 19 November 1998 to:

The International Aircraft Fire and Cabin Safety Research Conference

Presented by: Bill Leach, Code 4.3.5.1

NAVAIR Fire Protection Team Leader

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oo MAET MAET MAET NAVY RESPONSIBLE USE POLICY

• Stockpile– Halon Usage Factors & Aircraft Attrition Rates

• Minimize Use – Recycle

– Reduce Non-Fire Discharges & False Alarms

• Alternative R&D– Corporate Efforts

• TDP: Technology Development Program• NGP: Next Generation Program

– Navy Efforts• Gas Generator Technology• Water Mist Technology

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oo MAET MAET MAET NAVAIR HALON POLICIES

• In-Service Aircraft (Pre - 1993)– U.S. DOD Halon Stockpile

• New Aircraft Programs (Post - 1993)– Non-Halon System

– No Reliance on Stockpile

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oo MAET MAET MAET NAVAIR HALON POLICIES

• Old Retrofit Solution:– None Needed

– None Available

• New Retrofit Opportunity:– Enhanced (and Growing) Pressures on Stockpile

– Unexpected Forward Fit Solution (F/A-18E/F)

HIGH POTENTIAL FOR RETROFIT SOLUTION

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oo MAET MAET MAETFORWARD FIT SOLUTION (F/A-18E/F)

• E/F Specification Requirement– No Halon

– Better than or equal to C/D System• C/D System: 5.5 # of Halon 1301

• Same Bottle Compartment as C/D– No Growth Provision for New Agent Cylinder

• E/F Solution: HFC-125 (~ 6 pounds)

F/A-18E/F Solution Seems to Contradict Industry Knowledge

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oo MAET MAET MAET HALON ALTERNATIVE TECHNOLOGY DEVELOPMENT PROGRAM

• 1992 Start, 4 Year Effort• DOD Program w/ FAA Participation• Only “Corporate” Effort to Identify Chemical

Alternative for Halon– Extinguishing Performance; Toxicity; Material

Compatability; Agent Stability; Availability • TDP Answer: HFC-125

Predictions of 200 - 300% System Growth Required

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oo MAET MAET MAET F/A-18E/F PATH TO SUCCESS

Technology Technology DevelopmentDevelopment

F/A-18E/FF/A-18E/F

SolutionSolution

Baseline: Gas Generator–Thermal Extremes–Insensitive Munitions–Resulted in High Risk

New Baseline: HFC-125–Four Nozzle Distribution–Equal to or Better than Halon

Alternate Agents–Gas Generator–CF3I–Dry Chemical–HFC-125

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oo MAET MAET MAET F/A-18E/F TESTING

• Detailed Airflow Analyses– High Fidelity Engine Nacelle Simulator

• Agent Distribution Testing– Optimize Plumbing Scheme

• Fire Testing– Baselined to Halon Defeat Point

• Relight Condition

– Confirm Equivalence with Halon

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oo MAET MAET MAETF/A-18E/F TEST ARTICLE

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oo MAET MAET MAET

1998 HOTWC

HFC-125

EVALUATED DISTRIBUTION OPTIONS

N1

N2

N3

N4

N5N6

N1N2

N3

. N5

N6xx

F-18 Ext. BottlePres: 600 - 1800 psig

Exhaust

Exhaust

Air In

Nozzle Configuration Definition

Nozzle Opening (diam, inches) or [area in2]

Configuration N1 N2 N3 N4 N5 N6

EMD Open n/a n/a Open Open n/a(0.19”) (0.25”) (5/8”)

LRIP Open n/a n/a Open n/a Open(0.19”) (0.25”) (5/8”)

3 Nozzle Open Open Open Open n/a n/a(0.19”) (1/2”) [5/8] (0.25”)

4 Nozzle Open Open Open Open n/a Open(0.19”) (1/2”) [5/8] (0.25”) (5/8”)

LRIP + Open n/a Open Open n/a Open(0.19) [5/8] (0.25) (5/8”)

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Nozzle Placement(s)

“Agent”

To AMAD ENGINE AFT

E/F 4 Nozzle

(Outb”d)

( HFC-125 ImprovedDistribution)

“Agent”

5.6 lb @ 600 psi

( HALON )5.5 lb min @ 600 psi

“Agent”

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oo MAET MAET MAET GENERAL SYSTEM INSTALLATIONGENERAL SYSTEM INSTALLATION

FIREX BOTTLE

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oo MAET MAET MAETHFC-125 TEST RESULTS

Optimized HFC-125 is Competitive With HALON 1301

0

15

10

5

HALON 1301(5.5#)

HFC-125

EMD LRIP EMD LRIP 3Noz 4Noz

“Fir

e O

ut”

Tim

e ~

(Sec

)

Target Min

5.6#

ImproveDistribution

ImprovePerformance

6.3#

Baseline

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oo MAET MAET MAET F/A-18E/F TEST RESULTS

• HFC-125 System Proven to Meet or Exceed Halon Performance– HFC-125 Always Put Out the Fire– Several HFC-125 Test Points with No Relight

• Defined System Details for Production– Optimized 4 Nozzle Arrangement– 6.0 # Agent Minimum– 600 psi Nitrogen (Maintain Cold Temp Performance)

• HFC-125 System Selected to Enter Qualification Testing (End FY99)

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oo MAET MAET MAET HFC-125

• 1998 F/A-18E/F Engine Testing

VolumetricConcentration

Agent Mass(Pounds)

Design EquationPrediction(per TDP)

18.51% 4.87

Fire Test Data 8 – 9% 5.6

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oo MAET MAET MAET HFC-125 DESIGN EQUATIONS

• Application– Any New Use of HFC-125– Requirement: Concentration– Guidance: Mass– Some Level of Conservatism

• Option to Design Equations– Fire Testing– Less Agent Likely– Smaller, Lighter Solution for New Aircraft– Retrofit Possible

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oo MAET MAET MAET FIRE PROTECTION TRUTHS

• Halon 1301 is a Very Efficient Fire Extinguishing Chemical

• HFC-125 is a Less Efficient Fire Extinguishing Chemical than Halon 1301

• Halon 1301 Discharge Plumbing is Very Inefficient (Most In-Service Aircraft)

• By Addressing the Plumbing, HFC-125 Systems Can Be Made As Efficient as Halon 1301 Systems

System Equivalence is the True Goal!

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oo MAET MAET MAET FIRE PROTECTION TRUTHS

• HFC-125 is a Retrofit Option, NOT A DROP-IN!– Agent Discharge Plumbing Must be Optimized

• Detailed Airflow Analyses• Agent Concentration Measurement• Fire Testing

• Even Better Retrofit Opportunity on Helos and Other Cross-Plumbed Systems– Redundant Halon Bottles (Primary & Secondary)

– Couple Bottles for Single Discharge• 200% Growth Immediately Attainable• Possibility of Meeting Design Equations