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 04-21-04

“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 04-21-04

Background - Accident History 17 accidents between 1959 and present Three accidents in recent history 1990: 737-300 – Manila, Philippines, 8 Fatalities 1996: 747-100 – New York, United States, 230 Fatalities 2001: 737-400 – 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 04-21-04

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 04-21-04

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 04-21-04

GATC—Wichita, KS 04-21-04

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 04-21-04

FAA OBIGGS GATC—Wichita, KS 04-21-04

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 04-21-04

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 04-21-04

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 04-21-04

FAA Fire Safety Branch Website www.fire.tc.faa.gov GATC—Wichita, KS 04-21-04