But EgyptAir denied media reports yesterday that the co-pilot on board Flight 990 warned of a problem with a thrust reverser hours before the wide-bodied Boeing 767 crashed with the loss of all 217 on board. "That is not correct," an official of the airline said.
Investigators have still not narrowed down the range of possible causes why the flight from JFK to Cairo on Sunday morning crashed in to the ocean south of Nantucket, Massachusetts. Criminal sabotage has not been ruled out, even though nothing that has been found yet points to it. However, possible problems with its thrust reversers have come under special scrutiny after EgyptAir confirmed that the reverser in one of the jet's two engines was deactivated by its engineers days before the accident.
The only other fatal accident involving a Boeing 767 was in 1991, when a Lauda Air jet crashed into the jungle in Thailand killing all 223 passengers and crew. It was knocked from the sky when one of the thrust reversers, designed to slow an aircraft after landing, accidentally deployed in mid-flight.
The EgyptAir official was responding to reports that the co-pilot cited a problem with a thrust reverser when the jet landed in Los Angeles on Sunday, before it began its return journey to Egypt via New York. The official said the warning had to do with a tyre that was changed at Los Angeles airport.
Niki Lauda, the head of Lauda Air, said he doubted that a thrust reverser was the culprit in the latest crash, noting that modifications to the part recommended by Boeing after 1991 had been made by EgyptAir. "Assuming the plane was operated correctly, I can categorically rule out that the thrust reverser would deploy in flight," he commented.
Moreover, initial radar data from the last moments of the flight seem to point away from such a problem. In the 1991 crash, the reverser put the aircraft into a spiralling dive. The EgyptAir dive was apparently direct and extremely fast.
So fast, in fact, that the Boeing might have descended at more than 660mph. It could have been travelling faster than the speed of sound, officials said. At such a pace, it could have torn apart before hitting the sea's surface. Oddly, moreover, it took a sharp turn to the right when it reached an altitude of about 16,000ft before it vanished from radar.
Bad weather had all but halted the salvage effort yesterday, with 20ft swells in the area of the splashpoint. As soon as the seas subside, the USS Grapple will leave for the site from Newport, Rhode Island, with divers and a remote-controlled submarine equipped with cameras.
Investigators believe they have now pinpointed the signals of both "black box" instrument and voice recorders.