NTSB orders inspection of another Airbus

The rudder and tail fin of Flight 587 separated from the plane before it crashed into a New York neighborhood.

WASHINGTON (CNN) -- Federal investigators have ordered the removal and inspection of the rudder and tail fin of an American Airlines Airbus A300-600 involved in an in-flight incident in 1997.

The move comes as the National Transportation Safety Board (NTSB) continues to investigate the cause of last November's fatal crash of Flight 587 in Belle Harbor, New York, after takeoff from John F. Kennedy International Airport.

Investigators said the vertical stabilizer of the other Airbus, which flew as American Airlines Flight 903, will undergo ultrasonic inspection later this week to determine whether it sustained any damage during the incident when it "likely experienced" high-impact stress to its rudder and tail-fin section.

The incident happened on May 12, 1997, near West Palm Beach, Florida, as Flight 903 began its descent for a landing at Miami International Airport.

Investigators determined that the probable causes of the incident were the flight crew's failure to maintain adequate airspeed during level-off -- which led to an inadvertent stall -- and the pilot's failure to use proper stall-recovery techniques.

One person was seriously injured and a flight attendant suffered minor injuries in a period of some 34 seconds during which the aircraft entered a series of roll maneuvers and dropped from an altitude of 16,000 to 13,000 feet.

EXTRA INFORMATION In-Depth: AA Flight 587 crash    RESOURCES • Airbus A300

Investigators are also reviewing the flight recorder data from the 1997 flight to calculate the forces to which the tail section was subjected. That data could be useful in helping investigators pinpoint what kind of stress loads vertical stabilizers can undergo without showing signs of stress

Earlier this month, the NTSB asked the Federal Aviation Administration (FAA) to require pilot training on handling the vertical stabilizer. The request followed interviews with Airbus A-300 pilots, who were unaware that it's possible to make rudder movements that can cause catastrophic stress on the vertical stabilizer.

Flight 587's final phase of testing

The NTSB also reported Monday that it will begin the final phase of testing of Flight 587's tail section next week at NASA's Langley Research Center in Hampton, Virginia.

Experts will begin destructive testing on the tail section of the aircraft to determine if pre-existing defects or damage to the tail section could have been a contributing factor in the crash, which killed 260 people on the plane and five on the ground.

The NTSB said it had purchased a used rudder from another A300-600 aircraft to use for comparison as the examination of the accident components continues. The agency is looking for a used vertical stabilizer to use for the same purpose.