1. Engine Nacelle Halon Replacement, FAA, WJ Hughes Technical Center Point of Contact :Doug Ingerson Department of Transportation Federal Aviation Administration WJ Hughes Technical Center Fire Safety Branch, AAR-440 Bldg 205 Atlantic City Int'l Airport, NJ 08405 USA tel:609-485-4945 fax:609-485-7074 or 609-646-5229 email:Douglas.A.Ingerson@faa.gov web page:http://www.fire.tc.faa.gov/ International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA

2. International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Major Topics for Review Overview of Work, October ’02 – March ’03 iFinalizing Environmental Test Parameters iQuantifying Halon Replacement iEvaluating Pool Fire Behavior iFinding Certification Distribution Near Term Plans iComplete Certification Distribution Work iComplete Pool Fire Evaluation iEvaluate Varied Agent Discharge Impact on Reignition Time Delay iEquivalence Testing

3. SLIDE# 3 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA FINALIZING ENVIRONMENTAL TEST PARAMETERS Extinguishing agent storage temperature iReferring to the storage temperature of the extinguishing agent during fire testing iAgent storage temperature has been 100°F iDesire expressed for an additional storage temperature of –65°F iFINAL DECISION : Fire testing will be completed at an agent storage temperature of 100°F iBasis for decision 5Flammability behavior [Based on a system of fuel, air, and extinguishing agent within a fixed volume having consistent ignition energy (similar to ASTM E-695) [Increasing pressure requires increasing agent concentration to remain nonflammable [Increasing temperature requires increasing agent concentration to remain nonflammable 5Given this behavior for comparable combustion behavior [The peak concentration value for a higher temperature will provide adequate protection at lower temperature [The challenge is for the extinguishing agent to DISTRIBUTE and attain the peak value found at the higher temperature while being stored at a lower temperature [This can be demonstrated by non-fire, distribution test alone

4. SLIDE# 4 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA FINALIZING ENVIRONMENTAL TEST PARAMETERS Extinguishing agent storage temperature 2 Graphic from : Illustrating increasing flammability envelope with increasing temperature

5. SLIDE# 5 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA FINALIZING ENVIRONMENTAL TEST PARAMETERS Extinguishing agent storage temperature Illustrating increasing flammability envelope with increasing temperature Graphic from :

6. SLIDE# 6 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA FINALIZING ENVIRONMENTAL TEST PARAMETERS Extinguishing agent storage temperature iBasis for decision (continued) : 5Uncertainty due to gas analysis technology [NIST demonstrates possible difficulty with higher boiling point agent (CF3I) at low storage & environmental temperatures [Varying liquid/vapor fractions of extinguishing agent observed during discharge "Room temperature agent & fixture ventilation "Cold temperature agent/room temperature fixture ventilation "Cold temperature agent & fixture ventilation [NIST utilized relatively unobtrusive technology for gas analysis "No sample transport; sample analyzed in test environment during discharge events "Minimal impact on the agent distribution during its measurement [FAA Tech Center utilizing Statham-derivative technology "Gas sample is transported to sensor – sample is heated by transport path "Sensor assembly is a heated environment – sample is heated prior to measurement [Uncertainty at FAA Tech Center : "Gas analysis error - sample transport and measurement will heat and change liquid agent to vapor "The gas analysis error may not permit accurate description of the transport phenomena in the test fixture

7. SLIDE# 7 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA FINALIZING ENVIRONMENTAL TEST PARAMETERS Lower air mass flow rate iLower air mass flow in the test fixture at the FAA Tech Center is too large iLower air mass flow has been 1.0 lbm/s iDesire to see 0.2 – 0.4 lbm/s which match flows found in fielded nacelles iFINAL DECISION : Lower air mass flow rate will be 1.0 lbm/s iBasis for decision 5Work at FAA Technical Center founded on testing completed at 1.0 lbm/s 5Changing to lower mass flow will invalidate database for agent dispersion and fire testing 5The test fixture at the FAA Technical center is capable of 0.7 lbm/s minimum 5Decreasing ventilation rate typically decreases agent quantity required to meet certification 5Lower mass flows move fire protection design towards non-ventilated compartments

8. SLIDE# 8 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Quantifying a Halon replacement Initial step – Basis/Process iReignition time delay is the duration between the extinguishment of the fire and its subsequent reignition iEnvironmental constraints 5Test fixture set up for one macroscopic test scenario 5Macroscopic test scenario = one ventilation configuration + one fire scenario 5Agent discharged within 1 second 5Agent storage temperature of 100°F iA small collection of individually unique tests are performed iIntended to map the behavior of the replacement candidate iA quantity can be estimated as a possible equivalent to the performance of Halon 1301

9. SLIDE# 9 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Quantifying a Halon replacement Initial step - Illustration

10. SLIDE# 10 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Quantifying a Halon replacement Final step - Basis iProcess requires repeating 5 tests to determine if a quantity is halon equivalent iAn unsuccessful quantity can be determined in as few as 2 tests iThis process is based on the statistical behavior of past test results 5Based on 7 test sequences; each sequence contained 5 replicate tests 5Test sequences were varied conditions providing reignition delay results 5Evaluated the trend of the reignition time delay over the 5 tests 5Evaluation determined whether the sequence of 4 tests would continue to a fifth 5This process was successful for 6 of the 7 test sequences

11. SLIDE# 11 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Quantifying a Halon replacement Final step - Process i Process 5The average reignition time delay and sample standard deviation for halon are known 5Run tests 1 through 4 with the replacement candidate at repeated test condition 5Beginning with test #2 [Calculate the running average of the reignition time delay for the replacement candidate [Determine if the running average falls within +/- 1 sample standard deviation (halon) of the halon average reignition time delay [If yes, continue; otherwise change mass and start again

12. SLIDE# 12 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Quantifying a Halon replacement Final step - Process iProcess (continued) 5Run test #5 and perform the FINAL evaluation [The running average of the reignition time delay (RTD) for the replacement candidate must be equal to or greater than that of halon [The sample standard deviation for the replacement candidate must be less than or equal to that of halon

13. SLIDE# 13 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Background iPurpose 5Observe combustion behavior [Dependent upon a recirculation zone [Recirculation zone forms behind flame stabilizing baffle over the pool of fuel 5Determine threat for use in equivalence procedure iWork description 5Looked at impact on fire behavior [Varying upstream baffle height [Hot surface behaviors – tube arrays "2 tube diameters "2 tube lengths "2 positions above fuel surface "2 positions downstream from flame stabilizing baffle "2 exposed fuel surface areas [Continually operating electrodes [Characterize fire growth 5Performed tests without discharging agent

14. SLIDE# 14 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Upstream baffle height iReviewed literature for experience 5Work by Hirst, Farendon, et al. 5Indicated 1” baffle height worst case; demonstrated by : [Blow-off velocity [Agent concentration iRan tests to observe fire behavior related to baffle height 5Used baffle heights of 0.50”, 1.50”, & 2” 5Exposed fuel surface area of 10.8”x10.8” 5Fuel depth of 0.50” 5Tube array used to monitor heating ability of fire [4 straight tubes in a rhombus stack, 24” long x 0.50”OD [Supported 2.25” above fuel surface and 4.25” downstream from baffle iObservations; as baffle height increased : 5Tube array temperature increased 5Temperatures 16” & 30” downstream decreased 5Hottest tube array temperature NOT comparable to profiles observed in hot surface ignition in the spray fire scenario

15. SLIDE# 15 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Upstream baffle height - Illustration AIRFLOW FWD UP STA 502  STA 527 CORE Flame stabilizing baffle/rib Exposed fuel surface This assembly not present during testing STA 518 thermocouples

16. SLIDE# 16 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Hot surface/tube array - Descriptions iPurpose 5Further observation of the fire behavior 5Determine the surface area of the pool for the final threat in the equivalence process 5Determine worst case tube array for evaluation against agent discharge iAltered tube array characteristics 50.25” & 0.50” diameters 55” & 10” tube lengths 5Tube array supported 0.25” and 1” above fuel surface 5Located 2”, 4”, 8”, 12”, & 16” downstream from flame stabilizing baffle 510.8”x10.8” & 10.8”x20.5” exposed fuel surface areas 5Tube array consisted of 3 tubes stacked in an inverted triangular wedge 5Thermocouple imbedded in tube array at the middle of the tube length 5Fuel depth of 0.50” iRan multiple tests evaluating the various conditions described

17. SLIDE# 17 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Hot surface/tube array - Illustration 10.8” x 10.8” fuel surface area 1/4”OD x 10” tubes AIRFLOW flame stabilizing rib AIRFLOW UP + + + Tube Array End View thermocouple

18. International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA SLIDE# 18 Evaluating Pool Fire Behavior Hot surface/tube array – Observations iTube array temperatures attaining 1250 – 1325°F iTemperatures consistently hotter when : 5Tube diameter was 0.25” 5Tube array was downstream 4” or less from baffle 5Tube array was supported 1” above fuel surface iLarger fuel surface area produced greatest thermal output iLarger fuel surface had no apparent impact on heating the tube array

19. International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 SLIDE# 19 Evaluating Pool Fire Behavior Hot surface/tube array – Tube array temperatures

20. SLIDE# 20 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Continually operating electrodes - Descriptions iPurpose 5Further observation of the fire behavior 5Determine worst case electrode configuration for evaluation against agent discharge iConditions for analysis 5Electrode gap of 0.13” 5Position gap 1.25”, 0.25”, 0.016”, & 0” above fuel surface 5Electrode gap placed 0.5”, 2”, 5”, 10”, & 17” downstream from flame stabilizing baffle 5Electrode gap placed on fore/aft center line of the pool 510.8”x20.5” exposed fuel surface area 5Fuel depth of 0.50” 5No tube array iMarked fuel pan to determine flame propagation behavior iRan multiple tests evaluating the various conditions described

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23. SLIDE# 23 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Continually operating electrodes - Observations iPool did not ignite unless electrode gap was in contact with fuel surface iFlames propagated across the surface of the pool faster opposing the bulk air flow in the test section iShortest duration to full pan involvement occurred with mobile electrode gap located 17” downstream from the flame stabilizing baffle

24. SLIDE# 24 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Continually operating electrodes - Observations

25. SLIDE# 25 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Continually operating electrodes - Observations

26. SLIDE# 26 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Conclusions iVaried baffle heights 5No reason suggested by data that 1” tall baffle is not worst case 5Further evaluation required iTube array 5Tubes apparently not hot enough for hot surface ignition based on spray fire results 5Worst case tube configuration [Exposed fuel surface of 10.8” x 20.5” length [Three 0.25”OD x 10” long tubes [Tube array located 4” downstream from baffle and supported 1” above fuel iElectrodes 5Fastest pan fire developed when electrodes were positioned at the aft end of the pool 5Recirculation zone is clearly present 5Worst case electrode configuration [Location of 17” downstream from baffle [Electrode gap touched fuel at surface

27. SLIDE# 27 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Evaluating Pool Fire Behavior Conclusions (continued) iGeneral comments 5Tube array apparently not hot enough for hot surface ignition in any configuration attempted 5The hottest tube array was located above the fuel in a region where the electrodes could NOT ignite the pool 5Final determination to be made with worst cases tested individually & combined against the discharge of a fire extinguishing agent

28. SLIDE# 28 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Agent Distribution Search Background iFormer Halon quantities producing certification at a storage temperature of –65°F 55.2 lbf Halon 1301 @ ventilation of 2.2 lbm/s & 100°F 53.2 lbf Halon 1301 @ ventilation of 1.0 lbm/s & 280°F iThese quantities produced excessive concentration profiles since fire testing was occurring at at an agent storage temperature of 100°F iWork occurring to find agent quantities that will produce certification at a storage temperature of 100°F 55.2 lbf Halon 1301 will be in the 3.5 – 4.0 lbf range 5No estimate for reduction from 3.2 lbf Halon 1301

29. SLIDE# 29 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Agent Distribution Search Preliminary results 3.90 lbf Halon 1301 @ ventilation of 2.2 lbm/s & 100°F

30. SLIDE# 30 International Aircraft Systems Fire Protection Working Group Phoenix, AZ, USA26-27March 2003 Federal Aviation Administration WJ Hughes Technical Center, Fire Safety Section, AAR-440 Atlantic City Int'l Airport, NJ 08405 USA Near Term Plans i Complete certification distribution work 5Finalize work at ventilation rate of 2.2 lbm/s @ 100°F 5Accomplish work for the condition of 1.0 lbm/s @ 280°F iComplete pool fire evaluation 5Run new quantities of halon against the pool fire 5Determine which worst case to use in the equivalence procedure iEvaluate the impact of varied agent storage pressure on reignition time delay 5Store the same amount of agent in the same volume at the same temperature 5Alter storage pressure 5Observe impact on the reignition time delay 5Incorporate experience into the equivalence procedure iEquivalence testing