US regulators order modifications to 3'800 jets

US regulators said Tuesday they plan to order modifications on 3,800 commercial jets to reduce chances of a fuel tank explosion like the one that destroyed TWA Flight 800 in 1996.
The initiative, once dismissed as impractical and too expensive, could cost the industry at least USD$530 million over several years, the Federal Aviation Administration said.
“Many people said it couldn’t be done,” said FAA Administrator Marion Blakey. “Our people have really brought us to a breakthrough on virtually eliminating fuel tank explosions on aircraft like the one that brought down TWA 800.”
In that case, investigators concluded an electrical short ignited fuel vapors in the center wing tank of the older model Boeing 747. The plane exploded over the Atlantic off New York’s Long Island, killing all 230 people aboard.
Blakey said the FAA will propose a rule later this year requiring the industry to install a fuel tank safety device on new planes made by Boeing and Airbus and retrofit existing aircraft over a seven year period.
The device is designed to reduce the threat of combustion by neutralizing potentially volatile fuel-air mixtures in empty or emptying tanks. This is achieved by replacing oxygen with nitrogen-enriched air.
Certain models, like the Boeing 747 and 737 and the Airbus A320, will likely be modified first, regulators said.
FAA plans follow years of piecemeal regulation aimed almost entirely at mitigating potential ignition sources like wiring.
“We’ve known throughout that we’ve needed to address fuel tank flammability itself and this has proven to be a greater challenge,” Blakey said.
Boeing designed its system and conducted flight tests last summer and plans more next month. European-based Airbus has been further behind in developing its system.
Airbus spokesman David Venz said the manufacturer had no comment on the FAA’s plans. “We’ve been saying the same thing since TWA 800 — we have a completely different design from those tanks that have had problems.”
But following the lead of French authorities, the FAA proposed in November that US airlines modify wiring on probes that measure fuel quantity on 468 Airbus A319 and A320 planes.
Boeing spokeswoman Liz Verdier said the manufacturer will not wait for new FAA regulation to become final before starting work. “We’re doing it anyway,” Verdier said.
Boeing wants to roll out the first 747-400 with the fuel tank enhancement at the end of 2005 and plans to make retrofit kits available to airlines at the same time or soon after.