On July 17, 1996, TWA Flight 800, a Boeing 747 bound for Paris, exploded shortly after takeoff from New York's Long Island, killing all 230 people on board.

The National Transportation Safety Board has yet to determine the exact cause of the crash, but last fall it issued an "airworthiness directive" requiring the immediate inspection of the wiring of older 747s. In April, it recommended further inspections and design changes in the wiring of 747s and in Boeing 707s and C-130 transport planes, as well.

In May, mechanics discovered a fuel leak in a Boeing 737-200 that they believed was caused by the kind of electrical arcing suspected of causing the TWA explosion. As a result, the Federal Aviation Administration added Boeing 737s to the list, ordering that they be inspected within a week.

The agency gave the operators of Boeing 747s and 767s 60 days to make similar inspections.

While the NTSB is not expected to issue a final report for some time, its investigators reportedly believe that the same kind of arcing from the wiring in the center fuel tank of TWA Flight 800 sparked the explosion that brought the plane down.