How Overuse Of The Rudder Downed An Airbus A300 In 2001

The crash of American Airlines 587 is one of the worst in US aviation history, with 260 fatalities. It involved an Airbus A300 aircraft, which suffered a catastrophic loss of its vertical stabilizer shortly after takeoff from New York JFK and crashed into a residential neighbourhood in Queens. The cause was determined to be overuse of rudder controls, following wake turbulence from a previous departing 747-400.

American Airlines Flight 587

American Airlines Flight 587 was scheduled from New York JFK Airport to Las Americas International Airport in Santo Domingo in the Dominican Republic on the morning of November 12th 2001. It was operated by an Airbus A300B4 aircraft, with registration N14053. The aircraft had been delivered new to American Airlines in July 1998 and was one of 34 such aircraft operated by the airline (according to data from ch-aviaiton.com).

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American Airlines operated the A300B4 until 2009. Photo: Eduard Marmet via Wikimedia

Problems started during takeoff

Flight 587 was due to depart at 08:00 but was delayed by security checks during boarding. It pushed back and taxied for departure from runway 31L. It was cleared for takeoff at 09:13, with the takeoff roll starting at 09:14. During takeoff, nothing abnormal was reported, and the pilots and air traffic control communicated as normal.

Critically, it was taking off immediately after a Japan Airlines Boeing 747-400 (flight JL47 to Tokyo Narita). The controller had cautioned the flight crew about wake turbulence, and the A300 started to roll 1 minute and 45 seconds after the 747 departure. These flight details are based on information from The Aviation Safety Network.

The A300 took off as normal, turned left to climb over the Jamaica Bay and was directed to contact New York departure.

American Airlines is continuing to fight reservations giant Sabre about issues relating to US Airways more than a decade ago. Photo: Getty Images

Crashing into a residential neighbourhood

Problems began very soon after the pilots contacted New York departure. On first contact, the crew told the controller they were “climbing out of 1,300 feet for 5,000 feet.” They were then cleared to continue the climb to 13,000 feet and made a left turn to route to waypoint WAVEY. It was during this turn (based on the investigation later) that problems started.

The crew heard a rattling sound, and the aircraft began to yaw to the right. First Officer Sten Molin was flying the aircraft at this time, and he began to apply full left and right rudder alternately to counter the yaw and turbulence experienced. This was unsuccessful, and the aircraft soon quickly pitched down and entered an uncontrolled descent.

The lateral forces experienced had caused the vertical stabilizer (aircraft tail) to separate from the aircraft. The engines also separated from the aircraft as it descended rapidly. There was nothing that could be done at this point, and the aircraft hit the ground at 09:16, in a residential part of Queens, at the intersection of Newport Avenue and Beach 131st Street. All 251 passengers and nine crew onboard were killed. Five people on the ground were also killed.

There is a memorial to the AA587 victims in Rockaway park. Photo: Kai Brinker via Wikimedia

Investigation and cause of the crash

As it took place just over two months after the September 11th terrorist attacks, there was an initial fear that the crash was a terrorist incident. These accusations and investigation carried on until mid-2002, but there was no evidence found of any plot or any disturbance in the cabin.

The crash investigation began on the day of the crash. The team were able to collect and reconstruct large parts of the crashed aircraft and also quickly recovered the flight data recorder and the cockpit voice recorder. Although, the flight data recorder was cut off during the descent, as the engines were lost, causing a power failure. There were also hundreds of ground witnesses who provided descriptions of what they saw.

The investigation found that the A300 had flown into the wake turbulence of the larger 747 in front. This had caused the initial rattle and disturbances but was not the cause of the crash. The First Officer’s response of applying aggressive rudder input had caused excessive aerodynamic loads on the vertical stabilizer, leading to it snapping off. Disturbingly, the report concluded that if the pilots had not applied such rudder inputs, the aircraft would have stabilized and returned to normal flight.

Several contributing factors

Naturally, several major questions were raised by the crash and the pilot’s actions. Why did the First Officer take the action he did, and why did the vertical stabilizer detach?

Regarding rudder overreaction, most of the blame was placed on American Airlines. The investigation found that the airline inadequately trained pilots in the use of rudder input for dealing with wake turbulence. The abrupt shift from left to right rudder created more force than the tail fins were designed to take. It was noted that in training simulations (as part of the American Airlines Advanced Aircraft Maneuvering Program), American Airlines used a scenario with wake turbulence created from a Boeing 747, making a 90-degree roll. This would have a much larger effect than a normal bank angle, and as such, pilots were used to reacting more aggressively.

Making this worse was the fact that the A300 only needed light pedal force for rudder displacement (remember, this would be traditional mechanical control on the A300 rather than fly-by-wire control). American Airlines modified its training programs following the accident.

Carl Icahn of TWA sold valuable London routes to American Airlines in 1991. Photo: Getty Images

The other concern was that the vertical stabilizer was completely detached from the aircraft. This was connected using two attachments, one made of composite materials the other of aluminium. There were concerns that this composite use was less strong. But final findings were that they were simply stressed beyond their design limits, contributed to by earlier events in the aircraft’s history. The airline inspected other A300 aircraft tail assemblies, but the type was not grounded.

This was obviously a terrible crash, one of the worst in US aviation history. Even worse was the fact that it could have been avoided with different training or pilot actions. Feel free to discuss the events of the crash further in the comments.