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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. NAVY RESPONSIBLE USE POLICY. Stockpile
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RETROFIT OPPORTUNITY FOR HFC-125IN AIRCRAFT ENGINE SYSTEMSPresented 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
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
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
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
FORWARD 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
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
F/A-18E/F PATH TO SUCCESS Technology Development • Baseline: Gas Generator • Thermal Extremes • Insensitive Munitions • Resulted in High Risk F/A-18E/F • Alternate Agents • Gas Generator • CF3I • Dry Chemical • HFC-125 Solution • New Baseline: HFC-125 • Four Nozzle Distribution • Equal to or Better than Halon
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
HFC-125 EVALUATED DISTRIBUTION OPTIONS 1998 HOTWC
ENGINE AFT Nozzle Placement(s) “Agent” “Agent” ( HALON ) 5.5 lb min @ 600 psi ( HFC-125 Improved Distribution) “Agent” E/F 4 Nozzle To AMAD (Outb”d) 5.6 lb @ 600 psi
GENERAL SYSTEM INSTALLATION FIREX BOTTLE
15 HALON 1301(5.5#) 6.3# Improve Performance HFC-125 10 5.6# Baseline “Fire Out” Time ~ (Sec) 5 Target Min Improve Distribution 0 EMD LRIP EMD LRIP3Noz 4Noz HFC-125 TEST RESULTS Optimized HFC-125 is Competitive With HALON 1301
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)
HFC-125 • 1998 F/A-18E/F Engine Testing
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
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!
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