Fuel Tank Inerting Joint Airbus/FAA, A320 Flight Tests Presented by Dr. Ali Tehrani Systems Fire Protection Group Meeting Atlantic City, New Jersey Nov. 2003 Fuel Tank Inerting Joint Airbus/FAA, A320 Flight Tests SCS/SYS/N/17/3737_01.DOC

Aims and Objectives The main objectives of the flight test are to: Demonstrate supply of inert gas to the centre tank, throughout the flight profile, using the FAA prototype system, Assess the centre tank gas distribution over different flight phases, Validate the in-tank gas distribution (O2 concentration) measured with those numerically modelled, Assess performance of a typical ASM operating during different flight phases. SCS/SYS/N/17/3737_01.DOC Nov. 2003

Test Installation The source of Nitrogen Enriched Air (NEA) was obtained using equipment loaned from the FAA, Equipment was located in the cargo bay on an LD3 pallet. Bleed air provided by tapping into bleed air duct, NEA was introduced into the centre tank using a pipe normally used for ACT fuel transfer when ACT is fitted, The outlet housing configuration of the transfer pipe in the centre tank was used to incorporate a NEA discharge nozzle, Oxygen concentration in the centre tank was measured using the FAA sampling system OBUSS, This allowed measurement of oxygen concentration from 8 locations in the tank, Additional measurements of temperature and pressure were made in the centre tank and on the NEA generating equipment, Cooling air was supplied from the cargo bay environment, OEA (Oxygen Enriched Air) was discharged over board using existing drain mast. SCS/SYS/N/17/3737_01.DOC Nov. 2003

Outline of OBIGGS Equipment and Interfaces Isolation Valve Cooling Air Bleed Interface NEA Supply Interface Check Valves Cooling Inlet Interface NEA Injection Line Shut Off Valve Centre Tank Heat Exchanger NEA Flow Temp control valve, cabin controlled Fan Filter ASMs Heater High and Low Flow Valves (In common valve) Bleed Line Bypass Valve with pressure supply bottle Bleed Air Isolation, controlled via cockpit FAA PALLET Cooling outlet Interface Waste Flow Interface Discharge Line Outflow Valve Outside Aircraft Waste Flow (O2 rich) SCS/SYS/N/17/3737_01.DOC Nov. 2003

OBIGGS as installed on Pallet SCS/SYS/N/17/3737_01.DOC Nov. 2003

Centre Tank Oxygen Sensor Location Probe 1 Probe 2 Probe 3 Probe 4 Probe 5 Probe 6 Probe 8 Probe 7 SCS/SYS/N/17/3737_01.DOC Nov. 2003

O2 Measurement Locations in Centre Tank SCS/SYS/N/17/3737_01.DOC Nov. 2003

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Ground and Flight Testing Ground testing of the system included a period of 50 hours “mini-endurance” tests to gain confidence in the system operation. The flight testing phase included a number of 9 flights, exploring system performance over a range of; Tank fuel quantities Climb and descent rates Different OBIGGS operational configuration Total flight test time was approximately 20 hours. SCS/SYS/N/17/3737_01.DOC Nov. 2003

Flight Test Data – Oxygen Concentration SCS/SYS/N/17/3737_01.DOC Nov. 2003

CFD results and Data Points, Ground Operation, Adjacent to Vent Inlet SCS/SYS/N/17/3737_01.DOC Nov. 2003

CFD Results and Data points, Ground operation, Tank Average SCS/SYS/N/17/3737_01.DOC Nov. 2003

Comparisons of Modelling and Data points – Tank Average Measured Data Oxygen Concentration Predicted results Time (Min.) SCS/SYS/N/17/3737_01.DOC Nov. 2003

Simulation of Ground Test (CFD) SCS/SYS/N/17/3737_01.DOC Nov. 2003

Conclusion No major abnormal system operation was observed during different phases of the ground and flight test, Variation in supply pressure appeared to have a dominating effect on the overall system performance, Reasonably uniform O2 concentration observed within the tank during the climb and cruise, Good agreement with numerical prediction of the gas distributions for steady states and flight phases. Normal servicing of the aircraft was not hindered, but the maintenance crew were briefed on the operations associated with the potential hazards of nitrogen rich atmosphere. Time taken to return tank to all air environment was approx. 30 Mins. SCS/SYS/N/17/3737_01.DOC Nov. 2003

Lessons Learnt Thermal characteristic of the ASM needs further investigation. Impact on reaching the optimum operating temperature Operated in a conditioned cargo hold only investigated. A variable flow system may offer some advantages, Initial purging of the tank may impose additional ASM requirements post maintenance, Function of the filter needs further investigation. The filter used was oversized for this application. The FRS concept proposed by the FAA was demonstrated to operate during the limited flight trials. However, significant development is still required for a fully commercial operational system. SCS/SYS/N/17/3737_01.DOC Nov. 2003

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