TWA Crash Salvagers to Probe Under Sand With Special Sonar

Salvage experts working over the crash site of Trans World Airlines Flight 800 said Thursday they plan to use a special low-frequency sonar designed to find bits of wreckage buried beneath the ocean’s bottom.

Investigators have been using high-frequency sonar sensitive enough to search out objects as small as a clam sitting on the ocean floor. But a series of storms have churned the Atlantic and caused sand and silt to shift, further complicating the recovery process.

It is hoped that the sand-penetrating sonar will identify key missing buried pieces that could determine whether the Boeing 747 jet was brought down on July 17 by mechanical failure, a bomb or a missile. So far about 95% of the plane has been recovered, with no resolution to the puzzle. All 230 passengers and crew members were killed in the crash.

In an effort to rule out mechanical failure, divers have mounted an intensive search for a third fuel pump that serviced the plane’s center fuel tank--the site of a massive explosion. One theory is that an unexplained malfunction in the pump might have triggered an explosion.

Two other pumps--about the size of large soft drink cans--have been recovered by divers 110 feet below the Atlantic. They show no signs of a malfunction.

If the sonar can identify buried or partially hidden plane parts, it might not be necessary to mount a large-scale dredging operation, which carries with it risks that missing wreckage could be damaged.

Whether the special sonar will be successful is uncertain. “We are hoping to get some penetration,” said Navy Adm. Edward Kristensen, the on-scene salvage commander, at a briefing Thursday. “We might get more than eight inches or so, but it all depends what the bottom is. If it is silt, we may get very little penetration. If it is a sandy area, we may get more penetration. We are not sure what it [the sonar] is going to give us.”

Kristensen said with the passage of the hurricanes, divers are finding that portions of the ocean’s bottom shifted, partially burying some pieces of the plane. “Now the current itself has started to move the silt off some of these pieces and we are finding edges of things sticking up on the bottom,” he said.