NTSB: Tail Ripped From AA 587
American Airlines Flight 587 crashed into Belle Harbor on November 12, 2001 because First Officer Sten Molin, who was flying the A300’s departure from JFK Airport that day, “aggressively and unnecessarily controlled the wheel and rudder pedal inputs” to control the plane’s roll in such a way that the rudder exceeded its “bending moment” and was torn from the aircraft.
It also ruled out a tie between flight 587 and an earlier American Airlines flight designated as Flight 903, which experienced an upset involving its rudder on May 12, 1997.
“There is no evidence to suggest terrorist action,” said Robert Benzon, the NTSB’s lead investigator into the Rockaway crash. “The crash was caused by several human and mechanical factors that combined to bring down flight 587.”
Speaking about the Canadian newspaper report that a shoe bomber brought down the flight, he said, “Samples were taken from the cabin,” he said. “There was no indication of any residue of explosives in the plane’s wreckage, there were no events at the airport that would lead to believing that a terrorist act had taken place and the timeline was so condensed that such a scenario just does not fit with what we know.”
Benzon added that there was no evidence of aircraft wreckage on the floor of Jamaica Bay, as has been alleged by local residents who saw the plane in the air.
In fact, another NTSB investigator, William O’Callaghan, told the five-member NTSB Board, “We believe the witnesses [who said that they saw smoke and flame on the fuselage.] There are several reasons that they could have seen fire and smoke. The departure of the engines could have caused fuel to exit the aircraft and ignite, for example. There could have been compressor surging, where the engine goes sideways and there is smoke. That is kind of rare, but we believe in the non-sabotage nature of the crash.”
O’Callaghan recounted the agency’s findings about the cause of the crash in an hour-long report, using the toll-booth video, taken from the Marine Parkway Bridge and NTSB-generated graphics to explain.
He said that flight 587 was proceeding normally until it turned left to fly “Direct WAVEY,” over Belle Harbor towards a waypoint about 35 miles southeast of Rockaway, over the Atlantic Ocean.
According to the report, flight 587 encountered two episodes of wake turbulence generated by a heavier jet aircraft, a Japan Airlines 747 designated as JAL 47.
On the first encounter, the report says, Molin used his control inputs without a problem.
During the second wake encounter, just seconds later, however, the report says that he “used aggressive control inputs that were unnecessary,” and that those inputs created a sideslip that brought forces greater than the design forces and the tail was ripped from the plane.
“That wake encounter did not constitute an upset of the aircraft, nor did it constitute a potential upset,” the report says. “On that second wake encounter the first officer used inputs that were twice as large as those he used in the first encounter. He continued to use the rudder to control roll although it was not necessary.”
The report says that Molin moved the tail left and right at least four times in an “inappropriate use” of the rudder inputs.
“He moved the rudder beyond its mechanical limits a number of times, creating a growing oscillation. On the final rudder movement, the vertical stabilizer broke off and the plane lost control and crashed.”
The report added that the movements created a “high bending moment,” that was well beyond design specifications set by the Federal Aviation Administration (FAA).
Over the past several weeks, there has been conjecture in the press, including The Wave, that the 1997 upset of flight 903 might have predicted the problems with flight 587 had Airbus Industries, which manufactures the A300-600 that was involved in both incidents, been forthcoming to American Airlines about the problems with the aircraft rudder.
John Clark, an NTSB official, however, said that flight 903 provided no “eureka piece to the puzzle.” He used a chart to show the differences between the two incidents.
“Unfortunately, we could not predict anything for [flight] 587 from [flight] 903.
He refused to conjecture on whether Airbus had provided sufficient information to American Airlines after the flight 903 problem.
“I don’t think that I would even want to guess on the legal and moral obligations and whether Airbus met them,” he said.
Congressman Anthony Weiner, who sits on the House of Representative’s Aviation Subcommittee, thinks that there is a tie between flight 587 and flight 903.
“It’s mind boggling that the FAA attended a meeting in 1997 with American Airlines and Airbus, in which they talked about the same rudder problems experienced by Flight 587, on the same kind of plane as Flight 587 and thereafter took absolutely no action to improve training or to improve design or to improve oversight,” Weiner said in a prepared statement. “In fact, during the four years of finger-pointing and back and forth between American Airlines and Airbus, most of which foreshadowed what we are hearing today, the FAA stood by and did nothing.”
Weiner says that Airbus sent a letter to American Airlines in August of 1998, informing the carrier of its concerns regarding the improper use of the A300-600 rudder. That letter, Weiner says, was cosigned by an FAA administrator.
American Airlines said that the letter was too vague to constitute adequate notice of the dangers, according to the Congressman.
Many people, including a number of locals who witnessed the plane in the air prior to the crash do not believe the NTSB findings. The NTSB report, however finds that eyewitness reports are often “unreliable.”
The final report said that those sightings represented burning fuel and electrical fires.
The final report cited the finding that the cause of the accident was “an in-flight separation of the vertical stabilizer as a result of aerodynamic loads that were created by the first officer’s unnecessary and excessive rudder pedal inputs after the aircraft encountered wake turbulence.”
The report added that contributing factors were the “characteristics of the airplane’s rudder system design and elements of the airline’s pilot training program.”
Stan Molin, the first officer’s father, who was an Eastern Airlines pilot for 35 years and who taught his son to fly, is among those who do not agree with the NTSB. He told reporters that his son “was made a scapegoat” by the NTSB because it could not reveal the real reason for the crash. “[The NTSB] decided on the first day that it was pilot error,” Molin said. “Then they set out to prove it.”