Date: 06/06/1994. ."The NTSB has said the yaw damper on the doomed American 587 flight in New York had to be re-set before the crew could push back from the gate the morning it crashed......
However, an American Airlines Airbus preparing to land in Miami after a flight from Bogota, Colombia, on May 11, 1999, experienced control problems that were traced to the yaw damper.
An FAA report said that when the plane aborted the landing and flew over the airport, "the yaw deviations increased and became extreme." The plane landed safely.
The NTSB has said two wires in the yaw damper had been inadvertently reversed. The FAA issued a directive which appears to have corrected the problem".
and
"Location: Xi'an, China. .Airline: China Northwest Airlines. .Aircraft: Tupolev TU-154M. .Registration: B-2610. .Fatalities/No. Aboard: 160:160. .Details: The plane broke-up in flight 10 minutes after taking off. Auto-pilot induced oscillations caused the aircraft to shake violently. The autopilot yaw-channel was accidentally connected to the bank control and the bank-channel to the yaw controls".
Without implying this was in any way the same problem, it does show that faulty or incorrect wiring can induce an output capable of causing an aircraft to exceed limits and break up.
[ 06 February 2002: Message edited by: ORAC ]</p>