Bad steering sensorsBy Pete Pichaske
Phillips News Service
WASHINGTON _ The turbulence that rocked a Continental DC-10 Los Angeles-to-Honolulu flight 11 months ago, injuring eight people on board, was caused by faulty steering sensors that need to be replaced, the National Transportation Safety Board has found.
The board yesterday recommended that all "control wheel steering sensors" on DC-10s that have gold-plated silver wires, a material that could produce a short-circuit, be replaced with safer solid gold or platinum wires.
The sensors allow DC-10 crews to adjust flight path while the plane is on autopilot.
The NTSB found that a sensor on the May 21 flight malfunctioned and sent an erroneous signal to the autopilot computer, starting the plane's wild ride.
The NTSB also urged the FAA to warn all DC-10 flight crews of "the potential for airplane attitude upsets caused by faulty control wheel steering sensor input and the potential for overshoots in recovering from those upsets."
The board found that after the faulty sensor caused an initial plunge on the Continental flight, the airplane continued to rock up and down as the captain tried to level it off.
The board blamed the rocking on the "significant lag in airplane response" to the captain's steering.
"The Safety Board is concerned that the combination of false CWS sensor inputs with a lag in airplane response time during a flight crew's attempted recovery creates the potential for other upsets of DC-10 airplanes," stated the report.
An NTSB spokesman said yesterday the recommendations are the board's final word on the flight.
"These are measures to improve safety, measures that need to be addressed immediately," said Terry Williams.He said no other similar incidents involving DC-10s have been reported to the board.
The roller coaster ride on Continental Flight 75 began without warning about an hour after takeoff May 21, and passengers were bounced around repeatedly.
After the incident, the plane returned to Los Angeles, where it landed without incident.