Pilot is blamed in 2001 air crash

Secondary causes include Airbus rudder, flaws in crew training, NTSB says

October 27, 2004|By Sylvia Adcock | Sylvia Adcock,NEWSDAY

WASHINGTON - A pilot flying the Airbus that crashed into New York City three years ago caused the tail of the plane to tear off in flight by his "unnecessary and excessive" use of the plane's rudder, the National Transportation Safety Board concluded yesterday in the culmination of an exhaustive accident investigation.

The five-member board was unanimous in its finding, but members disagreed on the importance of what it found were two contributing factors in the Nov. 12, 2001, crash - a training program used by American Airlines that taught pilots to use the rudder when the plane is out of control, and the design of the rudder pedals of the Airbus 300-600 model.

In the end, the board voted 3-2 to emphasize a problem with the sensitivity of the Airbus rudder pedals over American's pilot training program.

The Airbus 300-600 crashed into Queens shortly after taking off from Kennedy Airport on a flight to the Dominican Republic. The fiery crash, which killed 265 people, occurred just two months after the terrorist attacks of Sept. 11 and initially raised fears of terrorism. But it quickly became obvious to investigators that the issue involved the actions of the pilot as he moved the rudder back and forth in response to wake turbulence from a Boeing 747.

The rudder, a large movable flap on the tail, is used to keep the plane flying straight if one engine has failed or if the pilot has to land in a crosswind. "The rest of the time, your feet should be on the floor," said Capt. David Ivey, an NTSB investigator.

Only since the Flight 587 accident has it become common knowledge among pilots that the tails of commercial aircraft are not designed to withstand the force of such rudder movements. A rudder limiting system in all planes is designed so that the rudder can't move as far when the plane is at high speeds because that could break the tail. But the limiter does not protect pilots from putting too much stress on the tail by moving it back and forth.

The pilot, Sten Molin, was reacting to the wake turbulence of a Boeing 747 when he moved the rudder back and forth several times. But NTSB investigator John O'Callaghan told the board yesterday that the wake was barely noticeable in the plane: "His actions were unnecessary and excessive because the effect of the wake turbulence on the aircraft was minor."

On the ground, when the pilot checks the rudder to make sure it is moving properly, he will push the pedals down to deflect it to its fullest extent. In the A300-500, that takes four inches of movement of the pedal.

But in flight, pushing the pedal down less than two inches will deflect the rudder all the way. Critics of the system say it doesn't give the pilot enough feedback, and in flight, it's very difficult to apply just a little bit of the rudder.

The A300-600 and the A310 are the only aircraft that use such a rudder pedal system. Later Airbus models are designed more like Boeing aircraft, keeping the amount of deflection in the pedal the same at any speed.

It's likely, some experts say, that Molin didn't realize he was going to deflect the rudder all the way when he put his foot on the pedal. Then, once it moved all the way to the right, sending the airplane into what's called a sideslip, he tried to correct it by moving the rudder the opposite way.

After the vote yesterday, Airbus said it was surprised at the board's concern over the design of the rudder pedal system and didn't believe it should be a contributing cause of the accident. American issued a statement saying the board should not have put most of the blame on the pilot and said its training program has been modified since the 587 accident.

Stan Molin of Connecticut, the father of Sten Molin, went to the meeting and heard the safety board's conclusions.

"My son didn't know it, the captain didn't know it, and now they are saying `pilot error,'" said Molin, a retired airline pilot. "He did something that even though he didn't know it was wrong, he's the cause. Where's the logic?

"There are so many things that Airbus could have done to make American Airlines, to make the pilots, more aware of the vulnerabilities of their design."

Newsday is a Tribune Publishing newspaper.

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