Anatomy Of An Investigation

NEW YORK: In the aftermath of Tuesday's tragic crash of TWA Flight 800, with the possibility of survivors ruled out, the focus turns Friday towards the complex investigation underway to determine the cause of the crash. TIME aerospace correspondent Jerry Hannifin reports that the NTSB has developed an efficient and effective system for piecing together airplane wreckage and pinpointing the probable cause of what was, in this case, an extremely powerful and violent explosion. "The NTSB puts together a "Go Team" which is headed by a member of the Board. The team is made up of highly specialized experts in propulsion (engine), air frame (fuselage), hydraulics, electronics and computer technology," says Hannifin. These experts and metallurgists, as they salvage pieces of the plane, will build a gigantic metal jigsaw puzzle in a effort to piece together the 747 airliner. They will study such factors as the direction in which particular pieces of the wreckage were bent, and the relative heat damage to different parts of the airliner, which provide vital clues to the precise source and direction of the explosion: a bomb inside the cargo department? an exploding engine? a missile from outside? "These people are so expert in their field that they can reassemble the plane with even the smallest pieces of metal," says Hannifin. Once the pieces are put together, FBI specialists perform tests on the plane parts to trace particles of outgassing. "Whether the explosion was a result of a TNT bomb or a synthetic Semtex explosive, a favorite of terrorist bombers, traces of chemicals and emissions residue can be detected on the parts," reports Hannifin. Once the voice data recorder and the flight data recorder, are found, they will enable investigators to reconstruct the final moments aboard Flight 800. -->