TWA Flight 800 crashed after the jet's center fuel tank exploded on July 17, 1996

May 9, 1999
Web posted at: 7:37 p.m. EDT (2337 GMT)

NEW YORK (CNN) -- Within six months of the crash of TWA Flight 800 in July 1996, investigators from the Bureau of Alcohol, Tobacco and Firearms had decided that mechanical failure, not terrorism, likely brought down the New York-to-Paris flight.

But it wasn't until 10 months later that the FBI withdrew from the case, a formal admission that the plane wasn't brought down by a criminal act, according to U.S. Sen. Charles Grassley (R-Iowa).

"The FBI, by failing to admit it was mechanical problems until almost one year later, it seems to me needlessly jeopardized the safety of our air travelers," said Grassley, whose Senate subcommittee will hold hearings Monday into the circumstances surrounding the TWA 800 investigation.

A focus of Monday's hearing will be whether the FBI sat on the ATF report. An FBI spokesman denied that charge to CNN, saying that the information was forwarded to the National Transportation Safety Board.

However, the NTSB -- which has had its share of jurisdictional feuds with the FBI since the TWA 800 crash -- says it has no formal record of receiving the January 1997 report.

Grassley, a long-time critic of FBI procedures, charges that the FBI felt it could boost its budget and image by prolonging the criminal investigation into the TWA 800 disaster.

NTSB officials will testify at Monday's hearing that the FBI dismissed scientific evidence early on that pointed to a mechanical failure. Yet, months after the ATF report, the NTSB's own vice chairman, Robert Francis, said the door was not closed to the possibility of sabotage, though a missile or a bomb were considered "less likely."

Grassley says he believes FBI put pressure on the NTSB to leave open the possibility of terrorism.

"I think the FBI has shown, going back to January of 1997, its ability to use its power and prestige to curb statements and truths other agencies were willing to give out," Grassley said.

The center fuel tank of the TWA 747 exploded while the jet was off the coast of Long Island, killing 230 passengers and crew. It is still not known exactly what caused the tank to explode, and the scientific investigation is continuing.

However, the NTSB subsequently called for inspections of the wiring of fuel tanks on older Boeing 747s.