Information from the cockpit and flight data recorders show the plane ran into two wakes from a Japan Air Lines 747 that took off 105 seconds before the American Airbus A300-600. The second wake occurred 85 seconds after the American plane took off and 18 seconds before it crashed.
After encountering the second wake, the plane experienced some side to side movements, which gradually got stronger and coincided with movements of the rudder. The board is investigating the rudder movements. The rudder and the tail fin fell off first, followed by the engines.
The NTSB is looking at whether the tail was weakened in 1994 when the aircraft encountered turbulance while flying to Puerto Rico. The turbulence was so severe that 47 people were injured. American Airlines President Donald Carty has said he does not believe the incident caused damage that could have contributed to the crash.