Design fault blamed for TWA crash

Some relatives wept as the conclusions were revealed

Design flaws in the Boeing 747 jumbo jet contributed to the explosion that destroyed TWA Flight 800 over the Atlantic Ocean four years ago, US safety officials have ruled.

At the end of its longest and costliest investigation, the National Transportation Safety Board (NTSB) faulted the aircraft's designers for placing heat sources beneath a fuel tank.

It said the probable cause of the disaster was an explosion of the centre wing fuel tank caused by inflammable vapours.

Jim Hall: Should passengers be told the age of aircraft?

The source of the ignition was most likely to have been an electrical short circuit, the NTSB said, adding that the wiring associated with the fuel quantity indication system may have carried the "explosive voltage" to enter the tank.

Boeing, the world's largest aircraft builder, had told the safety board it had found no evidence to support the idea that a "specific electrical system or component of the 747-100 fuel quantity indicating system ignited a fuel/air explosion".

All 230 people on board the New York-to-Paris flight were killed when it blew up off Long Island on 17 July 1996.

Wrongly assumed

NTSB chairman Jim Hall, summing up the findings, said the accident was not caused by a bomb or a missile, but by a chain of events "set in motion years before" by the manufacturers, and the Federal Aviation Administration (FAA), which regulates the aviation industry.

He said the FAA's design and certification policy wrongly assumed that "fuel tank explosions could be prevented solely by precluding all ignition sources".

A design flaw caused the catastrophic explosion, say experts

On the grounds that aged wiring could have been a factor in the tragedy, Mr Hall also ordered a study to check whether older aircraft are more prone to disaster - and whether passengers should be told the age of the plane on which they were travelling.

He said the review, to be completed by 15 November, should look for a link particularly in cases where there were "catastrophic accidents and in-flight fires".

"We are extending the life of many of these aircraft well beyond what they put as their economic design life," Mr Hall said.

"Most people understand that as you get older, things degrade."