Testing Supports Flight 800 Malfunction Theory New Tests In Nevada To Include Blowing Up Center Fuel Tanks

Ten days of flight tests of a Boeing 747 last month continue to support the theory that the explosion of TWA Flight 800 was caused by a mechanical malfunction, investigators said.

The tests, however, were not enough to identify a cause of the blast, and many more tests were scheduled for the next six months, said Bernard Loeb, director of aviation safety for the National Transportation Safety Board.

The flight tests on Long Island, along with tests in England in which explosives were set off, point to a malfunction, investigators said. But authorities have not ruled out a missile or a bomb as possible causes of the July 17, 1996 explosion, which killed all 230 people aboard.

Investigators gained “extremely valuable” information by testing the volatility of vapors in a jumbo jet’s center fuel tank, Loeb said.

He said investigators found the tests at Kennedy Airport “helped us far more than we ever imagined possible. It was a key step towards finding out the probable cause of this accident.”

An investigator who spoke to The Associated Press on condition of anonymity said the tests in England left behind wreckage that did not resemble the Flight 800 wreckage, further weakening a theory that a small explosive might have blown up the plane’s center fuel tank.

In the Long Island tests, the plane was outfitted with monitors to track the temperature, pressure and vibration of different parts of the center fuel tank.

Sometimes, the tests tried to simulate what happened to TWA Flight 800 before it exploded in the air shortly after takeoff, shattering and falling in a fiery mess to the Atlantic Ocean.

In one instance, air conditioning units under the center fuel tank were operated while the plane sat on a hot Tarmac, much as Flight 800 had when the plane was delayed before takeoff.

At another point, the plane duplicated the takeoff of Flight 800, rising above 13,000 feet just as the plane had before it exploded.

Overheated vapors are considered a prime suspect in the disaster because there was only about 50 gallons of fuel in the tank when the plane took off.

Tests expected to begin in several weeks will include explosions of center fuel tanks in the Nevada desert, culminating within six months in the explosion of an entire plane on the ground, Loeb said.