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 Airbus's Toulouse factory, 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, as 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. 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. Findings According to the official accident report, the first officer repeatedly moved the rudder from fully left to fully right. This caused increasing sideslip angles. The resulting hazardous sideslip angle led to extremely high aerodynamic loads that separated the vertical stabilizer. If the first officer had stopped moving the rudder at any time before the vertical stabilizer failed, the aircraft would have leveled out on its own, and the accident would have been avoided. The aircraft performance study indicated that when the vertical stabilizer finally detached, the aerodynamic loads caused by the first officer's actions produced of force on the rudder, meaning that the vertical stabilizer did not fail until far in excess of the of force defined by the design envelope. The vertical stabilizer's structural performance was determined to be consistent with design specifications and exceeded certification requirements. Contributing factors to the crash existed, as well. The first officer's predisposition to overreact to wake turbulence caused panic. American Airlines incorrectly taught pilots to use the rudder for wake turbulence recovery, resulting in