Probe Focuses On Fuel Tank Investigators Exploring Possibility Of Boeing 747 Mechanical Failure

Safety investigators are exploring whether the nearly empty center fuel tank on Trans World Airlines Flight 800 might have exploded in flight, although so far they have developed no such evidence.

While the FBI’s criminal investigation continues to look for evidence of a possible bomb or missile, National Transportation Safety Board investigators have never stopped asking what mechanical problems might have caused the Boeing 747 to abruptly break up in flight and kill 230 people.

Within that context, the center fuel tank has emerged as a top possibility in some unknown chain of events that could have provided enough energy to tear the plane apart. Navy search vessels also have yet to locate one of the plane’s four jet engines, leaving a catastrophic engine failure as a possible link in the chain.

Sources close to the investigation said Wednesday the two complete engines that have been located appear to be the outboard engines on each wing. Part of another engine has been found. The missing engine was directly abeam of the center fuel tank. If it exploded, debris could have flown into the center tank and possibly sparked an explosion of the vapors in the tank.

The center fuel tank, which can hold up to 12,890 gallons, was left nearly empty the night of the crash because Flight 800 was lightly loaded.

The sources emphasize there is no evidence so far of any problems with either the fuel tanks or the engines. Only about 25 percent of the aircraft has been recovered from the ocean floor, revealing little about a possible cause. On-board recorders show the engines operated normally to the end, and the tapes contain no evidence of fire alarms or other problems other than a split-second loud sound as the recordings end.

At least one of several possible enginedisaster scenarios apparently was eliminated Wednesday when Robert Francis, vice chairman of the safety board, announced that almost the entire right wing of the plane had been found with seven of its eight engine mounts still attached. Failure of these mounts, called fuse pins, have caused two 747 freighter crashes.

The 20,000-pound wing, one of the largest pieces recovered so far, was heavily damaged and showed some evidence of fire, possibly when the plane’s rear portion burst into flame.

As of early Wednesday, no pieces of the center fuel tank itself had been found.