Investigation
The A300-600 took off immediately after a Japan Airlines Boeing 747-400 on the same runway. It flew into the larger jet's wake, an area of turbulent air. The first officer attempted to keep the plane upright with alternating aggressive rudder inputs. The strength of the air flowing against the moving rudder stressed the aircraft's vertical stabilizer and eventually snapped it off entirely, causing the aircraft to lose control and crash. The National Transportation Safety Board (NTSB) concluded that the enormous stress on the rudder was due to the first officer's "unnecessary and excessive" rudder inputs, and not the wake turbulence caused by the 747. The NTSB further stated "if the first officer had stopped making additional inputs, the aircraft would have stabilized". Contributing to these rudder pedal inputs were characteristics of the Airbus A300-600 sensitive rudder system design and elements of the American Airlines Advanced Aircraft Maneuvering Training Program.
The manner in which the vertical stabilizer separated concerned investigators. The vertical stabilizer is connected to the fuselage with six attaching points. Each point has two sets of attachment lugs, one made of composite material, another of aluminum, all connected by a titanium bolt; damage analysis showed that the bolts and aluminum lugs were intact, but not the composite lugs. This, coupled with two events earlier in the life of the aircraft, namely delamination in part of the vertical stabilizer prior to its delivery from the manufacturer and an encounter with heavy turbulence in 1994, caused investigators to examine the use of composites. The possibility that the composite materials might not be as strong as previously supposed was a cause of concern because they are used in other areas of the plane, including the engine mounting and the wings. Tests carried out on the vertical stabilizers from the accident aircraft, and from another similar aircraft, found that the strength of the composite material had not been compromised, and the NTSB concluded that the material had failed because it had been stressed beyond its design limit, despite ten previous recorded incidents where A300 tail fins had been stressed beyond their design limitation in which none resulted in the separation of the vertical stabilizer in-flight.
The official NTSB report of October 26, 2004, stated that the cause of the crash was the overuse of the rudder to counter wake turbulence.
The crash was witnessed by hundreds of people, 349 of whom gave accounts of what they saw to the NTSB. About half (52%) reported a fire or explosion before the plane hit the ground. Others stated that they saw a wing detach from the aircraft, when in fact it was the vertical stabilizer.
After the crash, Floyd Bennett Field's empty hangars were used as a makeshift morgue for the identification of crash victims.
Read more about this topic: American Airlines Flight 587