NASA Will Examine TWA Flight 800's Fuel SystemBy Don Phillips
The Washington Post
The fuel system recovered from TWA Flight 800 will be examined and tested by NASA in an effort to determine what might have caused an explosion in the doomed aircraft's center fuel tank area, investigators said Thursday.
The Boeing 747's fuel pumps, fuel probes and the cockpit fuel management system, recovered by divers from the undersea crash site, will be inspected at Marshall Space Flight Center in Huntsville, Ala., by the same team that investigated the Challenger space shuttle explosion in 1986.
Robert Francis, vice chairman of the National Transportation Safety Board, gave only vague indications of what the NASA team would be doing as its part of the probe into the July 17 TWA crash that killed all 230 people aboard.
However, for more than a week investigators have been concentrating on the plane's midsection in the center fuel tank area, which showed signs of heavy blast damage and burns.
Sources close to the investigation have said that fumes in the nearly empty center fuel tank exploded, but there is no evidence yet whether the explosion was initiated by a bomb or a mechanical anomaly.
FBI laboratory tests have found traces of PETN, a chemical in plastic explosives that is widely used in bombs and in surface-to-air missiles, from wreckage retrieved from a seat in the section of the cabin from rows 17 to 27, the New York Times reported in Friday's editions. But the newspaper said law enforcement officials still were not ready to declare the demise of Flight 800 a criminal act.
In Washington, a senior law enforcement official said the Times report was "exaggerated" in suggesting that either a bomb or a missile brought down the 747. "All three of the theories" - bomb, missile or mechanical failure - "are still being considered" because there is "not definitive proof of an explosive device."
Another official familiar with the investigation, commenting on the report of traces of chemical, said, "It's not the smoking gun. It's a puzzlement."
If more evidence of it is found, however, the explosive device theory "may be right in a few weeks," another source said.
At a meeting Thursday in Washington that included Attorney General Janet Reno, Transportation Secretary Federico Pena, FBI Director Louis J. Freeh, National Transportation Safety Board Chairman Jim Hall and James Kallstrom, who is heading the FBI's investigation of the crash, the subject of the new chemical evidence was discussed. Those at the meeting were told that while it means there is some indication of a bomb, it doesn't rise to the level of a bomb declaration, according to an official familiar with the meeting.
"It's not enough," the official said.
One official contacted by the Associated Press suggested there are other possible explanations for the existence of a trace amount of PETN, or pentaerythritol tetranitrate. For example, a passenger, perhaps a soldier who worked with explosives, could have carried a trace amount of the material onto the plane inadvertently.
The Times said the chemical is used in explosion welding, powder metallurgy, demolition, rock blasting and "even for creating sculptures." It also is an ingredient in Semtex, which has been used in terrorist attacks worldwide.
The FBI has said that when there is sufficient evidence to declare the explosion a criminal act, it will take over the investigation from the safety board and pursue the culprit. That has not happened, although the FBI has been investigating the case as if it might have been an act of terrorism and has treated evidence in a way that it could be used in court.
Francis said the NASA team will be getting several pieces of wreckage, including the fuel pumps from the center tank, which have a history of electrical shorts but which have never been known to cause an explosion. Low-voltage fuel probes, which tell how much fuel remains in a tank, will also be sent to NASA, as will the portion of the flight engineer's control panel that deals with fuel.
Francis said while the ocean salvage operation will continue, one of two Navy salvage ships will probably be sent home in the next week to 10 days because most remaining wreckage is concentrated in one debris field where there is room for only one ship to operate.
As of Thursday, according to Francis, 209 bodies have been found. Seating charts indicate the missing 21 bodies were distributed roughly evenly throughout the plane.