1. FAA R&D Efforts Leading to Fuel Tank Inerting
Steve Summer
Project Engineer
Federal Aviation Administration
Fire Safety Branch, AAR-440
General Aviation Technology Conference & Exhibition
Wichita, KS
April 21, 2004
GATC—Wichita, KS

2. “The FAA is considering a Notice of Proposed Rulemaking for later this year that would help prevent fuel tank explosions by requiring that new systems – those that would reduce the flammability of fuel tank vapors on the ground and in flight – be installed on those Boeing and Airbus models whose air conditioning systems could cause heating of center-wing fuel tanks.”
-FAA Press Release, 02/17/04
GATC—Wichita, KS

3. Background - Accident History
17 accidents between 1959 and present
Three accidents in recent history
1990: – Manila, Philippines, 8 Fatalities
1996: – New York, United States, 230 Fatalities
2001: – Bangkok, Thailand, 1 Fatality
Accident Similarities
Heated Center Wing Tank (CWT)
Hot day
Long ground operations with packs running
Empty (residual fuel) tank
Explosion occurred on the ground/shortly after take-off
Exact ignition source was never located
GATC—Wichita, KS

4. Background – Fuel Tank Protection
For an explosion to occur, the fire triangle must be satisfied
Sufficient fuel vapor
Sufficient oxygen
An ignition source
Past attempts to preclude ignition sources from fuel tanks has had limited success
Inerting looks to eliminate the risk by reducing the oxygen concentration
Fuel
Oxygen
Ignition
GATC—Wichita, KS

5. Inerting Requirements
Ignition tests conducted at the FAA to determine the Limiting Oxygen Content (LOC)
Controlled parameters:
Pressure (altitude)
Fuel temperature/flammability
Oxygen concentration
Ignition source
GATC—Wichita, KS

6. GATC—Wichita, KS

7. OBIGGS System Development
Hollow fiber membrane technology uses the selective permeation properties of certain materials to separate air into two streams, one nitrogen rich and the other oxygen rich.
Materials are woven into hair-sized membranes and bundled by the thousands into a canister called an air separation module (ASM)
Pressurized air is forced through the membrane fibers, allowing fast gases to escape through the membrane wall and the nitrogen rich stream to pass through
GATC—Wichita, KS

8. FAA OBIGGS
GATC—Wichita, KS

9. Complete OBIGGS Development and Validation of Concept
Fire Safety Oversaw Construction of System, Installed it in Full-Scale 747SP Ground Test Article and Tested Capabilities
Concept was Validated and System Capabilities Predicted
Fire Safety Tested System with Airbus on an A320
GATC—Wichita, KS

10. Ongoing System Validation & Furthering of Concept
December 2003/May 2004: FAA/NASA 747 SCA Flight test
FAA’s OBIGGS system installed in aircraft pack bay #4
Further concept study as well as operational variations tested
Continuous CWT and wing tank flammability (hydrocarbon data being taken in-flight for first time)
GATC—Wichita, KS

11. Summary
FAA R&D used existing technology in an innovative way to develop a near term, simple, cost-effective solution fuel tank flammability reduction
System utilizing the FAA methodology can be developed using commercial aviation grade parts available immediately
Industry involvement in the R&D process (IASFPWG) has enhanced the FAA’s R&D work
Continued development of the basic concept by industry has the potential to yield even smaller, more efficient systems in the near future.
GATC—Wichita, KS

12. FAA Fire Safety Branch Website www.fire.tc.faa.gov
GATC—Wichita, KS