SONAR DETECTS POSSIBLE NEW TWA DEBRIS.
Using new bottom-piercing sonar, Navy salvage workers have located what could be additional wreckage from Trans World Airlines Flight 800, buried under a few inches of sand on the ocean floor.
Retrieving any remaining hidden shards provides the last, best chance of finding what James Kallstrom, an assistant director of the FBI, calls the ``eureka piece,'' which would show if an explosive charge or mechanical failure caused the plane to crash.
So in the next few days, divers with advanced military equipment normally used to find underwater mines should descend on the new sonar targets, walk along the sea floor waving the hand-held detectors, and listen for a rising squeal in their earphones indicating the presence of buried metal. Then, falling to their hands and knees, the divers will scoop out any material they find.
The same gear will probably also be used to seek any remaining bits - some as small as a ball-point pen tip - that might lie hidden under the sand where the densest fields of wreckage once lay, Navy officials said.
In the past few days, a newly deployed low-frequency sonar device that can ``see'' through a few inches of loosely packed sand identified several likely new sites of buried debris, a senior Navy official said. Previous sonar searches of the crash site used sound waves at high frequencies that can penetrate water but nothing much denser, to create a detailed image of anything lying exposed on the bottom.
The low-frequency pulses of sound from the new device are able to penetrate denser substances, but they provide less precise pictures.