FAA Proposes Rule for Reduction in Fuel Tank Vapor Flammability

December 9, 2005

The U.S. Federal Aviation Administration (FAA) proposed a rule intended to make aviation safer by reducing flammability levels of fuel tank vapors in certain new large passenger jets and 3,300 existing Airbus and Boeing planes.

The proposed rule calls for aircraft operators to decrease fuel tank vapor flammability levels both on the ground and in the air, which according to the proposal would decrease the possibility of an ignition source causing an explosion. Four fuel tank explosions that occurred over the last 16 years, which caused 346 fatalities, spurred the FAA's proposal.

One path to compliance may be fuel tank inerting, which replaces oxygen in the fuel tank with inert gas. Boeing plans to install such a system on its new planes.

The proposal is expected to cost roughly $808M over 49 years for the U.S. fleet, including $313M to retrofit the existing fleet, the FAA said. If approved, Boeing 737, Boeing 747 and Airbus A320 models would be the first aircraft to be retrofitted with center wing fuel tanks. Boeing has approximately 2,300 aircraft that would need to be retrofitted, while Airbus has nearly 1,000.

The FAA has issued more than 70 directives over the past nine years regarding fuel tank flammability safety, including those concentrating on pump manufacturing discrepancies, wire chafing and protection of the fuel quantity indication system.

The notice of proposed rulemaking is on display at the Federal Register and is available at http://dms.dot.gov, docket FAA 2005-22997-4.

Source: U.S. Federal Aviation Administration (FAA).