Thursday July 15, 9:23 pm Eastern Time

Officials struggle to find cause of 1996 TWA crash

By Tim Dobbyn

WASHINGTON, July 15 (Reuters) - Three years after 230 people died in the explosion of a TWA jumbo jet off the coast of New York, the U.S. National Transportation Safety Board's probe is drawing to a close with slender odds of ever pinpointing the exact cause of the blast.

NTSB Chairman Jim Hall said on Thursday that investigators still were hoping for a breakthrough.

``Realistically we know the odds are that we won't be able to do that,'' Hall said in an interview, referring to identifying the precise source of the explosion. ``Nevertheless, we are going to continue to attempt to do that until we've satisfied ourselves that we've fulfilled our fiduciary responsibility to the American people.''

Hall said he plans to hold a final meeting of the agency on the crash late this year or early in 2000.

Trans World Airlines (AMEX:TWA - news) Flight 800 fell into the Atlantic Ocean off the Long Island coast in flaming pieces on the evening of July 17, 1996, shortly after taking off from New York. Everyone aboard the Boeing (NYSE:BA - news) 747 was killed.

Within months of the tragedy, the NTSB embraced the theory that fuel vapors in Flight 800's center tank had exploded. The FBI, after pursuing theories of a bomb or a missile, later agreed with the theory that a fuel tank explosion downed the plane.

Hall said he hoped the families of the accident victims and the traveling public could take comfort in the amount of safety information obtained during the investigation.

Richard Penzer, of Lawrence, New York, whose sister Judy died in the crash, said the NTSB officials had done their best. ``I think they just don't know,'' he said.

The probe has led the Federal Aviation Administration and the aviation industry to review thoroughly fuel tank pumps and wiring for possible ignition sources.

Since the crash, the FAA has issued more than a dozen groups of airworthiness directives that require carriers and manufacturers to make fuel tank improvements or face fines or other enforcement action.

But not heeded so far have been the NTSB's suggestions for reducing the risk of an explosion even if a spark does get into the tank.

Discovering that the vapor above the fuel in a tank remains flammable much longer during a typical flight than previously believed, the NTSB's recommended remedies have included reducing the flammability of the vapor through cooling or altering fuel specifications.

An FAA industry advisory group concluded a year ago that none of the methods was cost effective.

Hall conceded that fuel-air explosions in planes were very rare events, but they had occurred and could happen again. The recommendations remained on NTSB's ``Most Wanted'' list of safety improvements.

``As a member of the traveling public, I would always be concerned if the regulators and the industry are not trying to do everything they can to take information from an accident investigation and make the necessary changes to provide the maximum protection,'' Hall said.

Some of the research commissioned by the NTSB from laboratories around the world continues. ``We hope to have most of it concluded by the end of this summer so the staff can begin writing the final report,'' Hall said.

Family members of those who died in TWA Flight 800 will be allowed to view the wreckage of the plane this weekend.

The crumpled outer skin of the plane recovered from the Atlantic Ocean sits reassembled in a hangar on Long Island.

Hall hopes the wreckage eventually will be moved to Washington, where it will be the centerpiece of an international training academy for accident investigators.

``I think that would be the most fitting memorial, the most fitting use of...the largest and most expensive reconstruction of an aviation accident in history,'' he said.