NEW YORK, Nov. 15 (UPI) -- National Transportation Safety Board officials said Thursday that American Airlines Flight 587 tipped sideways seconds before it crashed after being hit twice by turbulence left by the wake of the Boeing 747 that took off in front of it.
Information from the Airbus A-300 jet's flight data recorder, recovered Tuesday near the crash site in Queens, N.Y., indicates two separate "wake encounters" about 20 seconds apart, NTSB Chairwoman Marion Blakey told reporters.
The second turbulent blast, just prior to the crash, "was similar in intensity to the first," she said.
At the beginning of the final eight seconds of recorded data, the pilots were still in control of the aircraft, Blakey said. During the last part of these eight seconds, however, "rudder position data became unreliable." It was at this point, she said, that the pilots lost control of the aircraft.
Tom Haueter, the NTSB's deputy director of aviation, said the plane banked sharply to the left within eight seconds of the second blast of turbulence.
"Obviously, the whole time we're talking about is the last eight seconds," he said. "We have eight seconds we're going to be looking at in extreme detail."
The NTSB is investigating the possibility that turbulence from the Japan Airlines 747 that took off about one minute and 45 seconds before the doomed American Airlines flight might have snapped the plane's tail off the fuselage, causing the plane to fly out of control.
The NTSB initially indicated that the two planes had taken off within accepted safety parameters -- two minutes apart. Later, investigators acknowledged the interval between takeoffs was shorter.
Blakey and other investigators said they had not concluded that wake turbulence was to blame in the crash, but said this possibility was being looked at.
Yesterday, NTSB board member George Black Jr. said the fittings that fasten the plane's tail fin to the fuselage were located. These fittings are typically inspected every five years and this particular plane's were last checked in 1999, he said.
Still, he acknowledged that one of the plane's fittings had been repaired in 1988.
"The left center fitting that holds the fin onto the fuselage, was found to be delaminated and it was repaired," he said, adding that the manufacturer said no further work was needed on it following the repair.
The plane's rudder and tail fin have been removed for investigation, Blakey said Wednesday.
NTSB investigators have said the organization expects to mandate fleetwide inspections of the tail sections of the type of aircraft in question.
Flight 587 plunged into the Rockaway neighborhood of Queens, destroying several homes, killing the 260 passengers aboard and five people on the ground.
On Tuesday, the New York Police Department identified the five missing as: Thomas Concannon, 79, and Helen Concannon, 73, retired husband and wife; Catherine Lawlor, 48, and Christopher Lawlor, 24, mother and son; and Frank Pomponio, in his 40s. All lived in the 200 block of Beach 131st Street.
Rockaway was home to many firefighters and policemen killed in the Sept. 11 attacks on the World Trade Center in Lower Manhattan.
