Investigation Summary
The investigation focused on the structural failure of the vertical stabilizer's composite attachment lugs. While the aircraft encountered wake turbulence from a Japan Airlines Boeing 747 that had departed two minutes earlier, the NTSB determined the turbulence itself was not sufficient to cause structural failure. Instead, the first officer responded with a series of rapid, full-deflection alternating rudder inputs. These inputs created aerodynamic loads that exceeded the ultimate design strength of the vertical stabilizer. The A300-600 rudder system was found to have a high sensitivity, requiring relatively low pedal force for full deflection at high speeds, which contributed to the pilot's over-control.
Final Conclusions
The NTSB determined the probable cause was the in-flight separation of the vertical stabilizer due to loads beyond ultimate design created by the first officer's unnecessary and excessive rudder pedal inputs. Contributing factors included the sensitive design of the A300-600 rudder control system and elements of the American Airlines Advanced Aircraft Maneuvering Program (AAMP), which may have encouraged pilots to use the rudder aggressively during upset recovery.
Video Analysis
The Tragic Crash of American Airlines Flight 587 — An analysis of the events leading to the structural failure and crash of AA587 in New York City, just two months after the 9/11 attacks.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Rudder Control System
A system designed with high sensitivity on the A300-600, where pedal feel forces do not increase significantly with airspeed.
Vertical Stabilizer Lugs
Composite attachment points that connected the tail fin to the fuselage; they failed under extreme lateral loads.
Rudder Travel Limiter
A system that restricts the maximum possible rudder deflection as airspeed increases to prevent structural damage.
Interesting Facts
- 01The vertical stabilizer and rudder were found in Jamaica Bay, approximately one mile from the main wreckage.
- 02The aircraft was flying below its design maneuvering speed (Va), but the NTSB clarified that Va does not protect against multiple, alternating full-control inputs.
- 03The A300-600 rudder system requires only 1.2 inches of pedal travel for full rudder deflection at the accident speed.
- 04All 260 occupants (251 passengers, 9 crew) and 5 people on the ground perished.
- 05The accident occurred exactly two months and one day after the September 11 attacks, initially sparking fears of terrorism.
Safety Actions & Advisories
Rudder Sensitivity Modification
Recommendations were made to modify the A300-600 rudder control system to increase the pedal force required for large inputs at high speeds.
Upset Recovery Training Reform
Airlines were required to revise training programs (like AAMP) to emphasize that rudder should not be used for roll control during wake turbulence or upset recovery.
Maneuvering Speed Definition
The FAA clarified the definition of design maneuvering speed (Va) to ensure pilots understand it only protects against a single full-control input in one direction.