New York — Neither turbulence from another jet nor pressure placed on the rudder by a desperate pilot should have been enough to snap off the tail of Flight 587, aviation experts said Friday raising the prospect that something was wrong with the plane before it left the ground.
"I think there was a pre-existing structural problem with the tail," said Greg Feith, a former National Transportation Safety Board investigator. "It was going to fail regardless. It just so happened the conditions were right."
The American Airlines Airbus A300 plunged into a New York neighborhood Monday, shortly after taking off from Kennedy Airport for the Dominican Republic. The crash killed all 260 people aboard and five more on the ground.
The cause of the crash has not been determined, but investigators have focused on the jetliner's tail assembly, which came off before the crash.
The Federal Aviation Administration on Friday ordered airlines to immediately inspect the tail assemblies of their Airbus A300-600 and A310 planes. American and two cargo carriers, FedEx and United Parcel Service, have about 135 of the French-made jets in their fleets.
NTSB Chairman Marion Blakey said the frantic efforts of the pilots aboard Flight 587 to save their plane also should provide clues to what went wrong.
"We do know, just from what we can see on the flight data recorder, that the pilots were trying to actively fly that plane out of the problem," Blakey told the Associated Press, cautioning that this does not imply pilot error. Investigators have already suggested the pilots wouldn't have known the tail fin was missing.
Investigators say Flight 587 shook violently from side to side after encountering two wakes generated by a Japan Air Lines 747 that took off about two minutes earlier from the same runway at Kennedy. Because of its size and weight, the four-engine 747 generates heavy turbulence.
While Flight 587 was more than four miles behind the JAL jumbo jet, as required by FAA regulations, NTSB spokesman Keith Holloway said the agency was looking at whether to suggest keeping planes farther apart.
Experts suggested more distance wasn't needed in this case.
"The wake vortex of a 747 should not bring down an aircraft," said Tom Ellis, a spokesman for the Nolan Law Group, a Chicago firm that represents victims of airline accidents. "There's got to be something that interferes with the ability to recover."
Examination of the two black boxes the data recorder and the cockpit voice recorder indicates that at one point, the pilots tried to use maximum power to regain control. But they were probably unaware the jetliner's tail had broken away, and the NTSB's George Black Jr. said calling for maximum power suggested they were in "recovery mode."
"And they might be recovering from the wrong thing, because they don't know" about the missing tail, he said.