WASHINGTON -- Suspicion mounted yesterday that the crash of EgyptAir Flight 990 was caused by a human hand and not mechanical failure as federal investigators released evidence that experts said may indicate a struggle for control in the cockpit.
While steadfastly avoiding speculation, National Transportation Safety Board Chairman James Hall said the Boeing 767's flight data recorder showed the jet's two engines were shut down as it dived toward the ocean and that the "elevators" -- important control surfaces in the tail that regulate climbing and descent -- were split, one up and one down.
"This does not look like any kind of structural or system failure," Barry Schiff, a former TWA captain and air crash consultant, said after reviewing Hall's new information. "There was something funny going on in that cockpit."
Separately, an engineer said that a split in the elevators can occur if one of two control yokes in the cockpit is pushed forward forcefully, while the other is pulled back equally hard. The elevators, part of a wing-like structure in the plane's tail, are used to control the rate of climb or descent. Normally, they operate in tandem.
"It looks as though there were contrary maneuvers -- one person does one thing and another person does another," Schiff said.
As for shutting off the engines, "Once you do that, you commit yourself to an oceanic ending," he said.
Hall also revealed that the plane's passengers were in a state of weightlessness for about 20 seconds of the terrifying dive.
In New York, FBI spokesman Joe Valiquette said that law enforcement officials have not found evidence that a criminal act was to blame for the Oct. 31 crash off the coast of Nantucket Island, Mass., which killed all 217 people aboard.
"We haven't discovered anything that so far would indicate that a crime or terrorist act was committed," Valiquette said. While such events are extremely rare, jetliners have been crashed by intruders invading cockpits, and by suicidal crew members.
Briefing the media at a command post in Newport, R.I., Hall said that he hopes recovery of the jet's cockpit voice recorder will explain what happened. An intense, around-the-clock search is being made for it.
"We cannot at this time explain the circumstances that were occurring on Flight 990 that resulted in [this] flight profile," Hall said. "We will not attempt to speculate about it."
The NTSB is considering every possible explanation, including malfunction, a human blunder or a combination of the two. The FBI is examining the plane's passengers, cargo and crew for any indication of a criminal act, such as a takeover of the flight deck or detonation of a small bomb. The NTSB is leading the investigation, with the FBI in a supporting role.