Unrelated To AAL New York Crash, But Just As Deadly

It may not have been the fatal flaw in American Airlines Flight 587's 2001 crash, but it could be a big problem for future flights of the Airbus A300-600.

According to the New York Times, the NTSB has turned up a flaw in the rudder design of the A300. Investigators say the rudder of the A300-600 can swing too far during rapid acceleration, causing severe tail damage or even delamination of the aircraft. The NTSB said the governor that limits the rudder's movements -- the "limiter" -- didn't keep up with rapid changes in the speed of the aircraft.

Airbus apparently was ready for the finding. Spokeswoman Mary Ann Greczyn said in a statement that a complete redesign of the empennage was in order. "We expected it was coming. It will add another level of safety for those extraordinarily rare times when there are rapid changes in air speed due to aircraft upset."

At the focal point of the finding wasn't the November 12, 2001 crash of American Airlines Flight 587, but another incident involving an American Airlines A300-600 in 1997. In that incident, a flight crew member was injured when the aircraft, flying near West Palm Beach (FL), dramatically increased velocity. The NTSB said the limiter couldn't keep up with the rapid change in airspeed. The aircraft subsequently lost about 3000 feet in altitude as the crew struggled to regain control.

In its investigation of the 1997 incident, the NTSB said the limiter system simply couldn't keep up with airspeed changes of more than 2.4 knots/second. The A300-600 flying near West Palm seven years ago was accelerating at approximately 10 knots/second.

American Airlines has been locked in a bitter battle with Airbus over liability in the 2001 crash at Belle Harbor (NY). All 260 people on board Flight 587, as well as five people on the ground, were killed after the copilot, apparently fighting severe wake turbulence, swung the rudder drastically from side to side. As a result, the NTSB says the vertical stabilizer departed the aircraft, leading to the crash.

Now, American says it is already training its A300-600 pilots to avoid "the specific shortcomings in the Airbus A300-600 rudder control system that the NTSB recommendation involves."

FMI: www.ntsb.gov