SMITHTOWN, N.Y. -- Federal investigators have created a sophisticated computer simulation of the final moments of Trans World Airlines Flight 800 showing that almost everything in the first spray of metal, luggage, and other material blown from the airplane came from one confined area on the right side of the jet, above and ahead of the wing.
The investigators say this simulation, a standard part of crash investigations, has helped them visualize the probable focal point of the explosion that split the plane.
Investigators examining wreckage from that section of the Boeing 747 say they have found several new hints that a bomb might have exploded there, causing the airplane to crash July 17, killing all 230 people aboard.
Nonetheless, senior law enforcement officials insisted that the new evidence did not push them appreciably closer to the point where they could officially declare that the plane crash was the result of a criminal act.
An aviation expert and a law enforcement official who is an explosives specialist said they saw several fist-size holes that had been punched through the backs of two seats on the far right side of row 23. That is in the center of the area pinpointed by the computer as the site of the initial blast. Both spoke on condition of anonymity.
The holes in the sheet metal on the seat back are pushed through from the rear, indicating that the enormous force that created them came from behind, the explosives expert said. Row 24, the seats just behind them, is missing, he added.
No similar holes have been found in other seats, the aviation expert said.
The explosives expert said that a lot of wreckage from rows 20 to 27 was still unaccounted for, but added that many of the pieces investigators do have hold "very suggestive damage."
"That's where the violent event happened," he said.
The microscopic traces of the plastic explosive PETN, discovered during testing at the FBI laboratory in Washington, were found in this general area.
At a news briefing yesterday, Robert T. Francis, the vice chairman of the National Transportation Safety Board, said only that seats from that area were "fairly heavily damaged, compared to the other parts of the airplane. There's more fire damage to the seats in that area."
Still, the explosives expert said: "We just don't have that one piece yet, the one piece that would let you call it a bomb. We're real close. We're just not there yet."
In a sign that the investigators were not content to examine just one area of the plane, Francis said yesterday that the scaffolding supporting the reconstruction of the forward part of the airplane would be expanded so the hump atop the first-class cabin could be put in place for study. This would allow fire experts to assess more easily the fire damage that apparently swept the front cabin.
But it was clear from the statements of several investigators that the wreckage already assembled was producing many clues.
One of the best indicators of the focal point of the initial blast appears to be the passenger seats, many of which have been assembled in their respective rows in one of four hangars in Calverton, N.Y., that investigators are using.
Many of the seats from the section of the plane of greatest interest to investigators -- rows 17 to 28 -- have been placed in numbered squares marked off by tape on the hangar floor, according to several people working there.
In row after row, tattered seats are burned or ripped or have parts missing. But based on the computer simulation and other evidence, one area stands out as the likeliest candidate for the initial blast, several investigators said: at the right end of row 23, directly above the center fuel tank and about 15 feet behind the spot where the leading edge of the wing joins the fuselage. This is where the metal backs of two seats are perforated by the fist-size holes.
It remains possible that something other than a bomb caused the holes in the seats, the investigators noted. But they said it was hard to explain the lack of similar damage on other seats, which leads to speculation that the holes were caused by a powerful and localized blast.
Pub Date: 8/30/96