Federal investigators have zeroed in a possible cause of the crash of TWA Flight 800 off Long Island 14 months ago, CBS News reported Wednesday.
Citing unspecified sources, CBS said the theory focused on the fuel measuring system and seven tubelike probes inside the 747's center fuel tank, which exploded July 17, 1996, shortly after the Paris-bound flight left New York, killing all 230 on board.
The probes are connected by low-voltage wires to cockpit gauges, but in places those wires are tightly bundled with high-voltage wires. The sources said high voltage could have leaked onto a low-voltage wire through cracked insulation or by a magnetic transfer, reaching the fuel probe and triggering the deadly explosion.
Boeing, which makes the 747, held that such a scenario would have required an unprecedented series of unlikely failures.
New tests have ruled out theories that a bomb or missile brought down the plane, and three other mechanical failure theories have not panned out, CBS said.
By process of elimination, the "fuel probe and voltage transfer" scenario has emerged as the clear front-runner, CBS said.