Final Rule Expected By End Of Year

Get set to learn a new aviation term during 2007: fuel tank inerting. It refers to pumping inert gas into aircraft fuel tanks as they're depleted, to prevent a build-up of explosive vapors. It's thought such a system could have prevented the explosion of TWA Flight 800 over the Atlantic off Long Island in 1996. Later this year, the FAA will issue a final rule on just how aircraft will be expected to implement the system.

Fuel tank vapors have been set off by a number of different ignition sources over the years. Wiring malfunctions might be resolved with design improvements, but there's not much aircraft designers can do to prevent lightning. That is why manufacturers and the FAA are focusing on how to remove the flammability, instead of sources for electrical sparks.

"It's taken the FAA too long to do the obvious," said former NTSB chairman and fuel-inerting advocate Jim Hall. "Any rule-making process in Washington, DC, is weighted toward the industry and toward delay. That's why I realized early on in my years at the NTSB that if you were going to do anything for the public good, you had to be vocal and persistent."

What is known so far is that the equipment will add weight and cost to airliners, and the FAA wants existing planes retrofitted. The FAA says it will cost the airline industry about $800 million over the next half-century. The industry says costs will be over a billion dollars.

As Aero-News reported, Airbus, in particular, is fighting the rule -- and indeed, aircraft registered outside the US will not have to comply. On the flip side, Boeing is embracing the idea... and will equip its forthcoming 787 Dreamliner with a system which creates nitrogen in the engines, and pumps it to the tanks. The company will also make the system standard equipment on 737s, 747s, and 777s beginning next year.

"It was the right thing to do," said Mike Sinnett, Boeing's director of systems for the 787 program, to the Seattle Post-Intelligencer.

The NTSB wants the FAA to extend the rule to cover other transport category aircraft, as well.

FMI: www.faa.gov