Safety panel also cites Airbus' poor design, airline's flawed training

Washington -- The National Transportation Safety Board on Tuesday said the crash of American Airlines Flight 587, the second-worst in American history, was caused by the pilot's "unnecessary and excessive" use of the rudder. But flawed training by the airline and poor rudder design were major contributing factors, the board said.

The plane, an Airbus A-300, crashed shortly after takeoff from Kennedy International Airport on Nov. 12, 2001, killing all 260 people on board and five more on the ground in the Queens borough of New York City.

Encountering turbulence from the wake of a Boeing 747 that had taken off shortly before, the pilot moved the rudder back and forth to try to keep the wings at the proper angle, pushing the plane into a fatal oscillation, according to staff members of the safety board. The force of the wind eventually ripped the vertical tail fin off, sending the A-300 plunging into several houses near Jamaica Bay.

Sten Molin, the first officer, was at the controls. The board said that he pushed the rudder too far to one side and then overcorrected by pushing hard in the other direction, and that the crash would not have occurred had he not touched the rudder. But the board also noted that the rudder control system on the A-300 was overly sensitive and that American's training methods may have misled pilots into thinking that using the rudder was the only option in that situation.

The five-member board agreed unanimously on the causes, but disagreed over whether the training or the tail sensitivity should rank second.

The crash investigation exposed a widespread misunderstanding among pilots about when it is safe to use the rudder. For all airliners, there is a "maneuvering speed" above which rudder use is unsafe. Many pilots thought that if they were below maneuvering speed, any rudder use was allowed.

In fact, to be certified as airworthy, a tail has to be sturdy enough so that if the rudder is pushed as far as it will go in one direction, the plane is still flyable. But a tail is not meant to withstand the rudder being applied in alternating directions.

Engineers apparently did not convey this to pilots, however.

More Airbus news here