AIR FRANCE: WAS IT A FATAL GLITCH?

摘要

Investigators probing the crash of Air France Flight 447 are focusing on the possibility that equipment malfunction may have caused the plane essentially to crash itself. A sheaf of fault messages sent automatically to Air France's maintenance department show that instruments aboard the Airbus 330 were reporting different airspeeds, possibly because precipitation had clogged sensors known as Pitot tubes. The pilot and copilot receive airspeed data collected by separate sensors, meaning that if either failed, the two pilots likely received conflicting information. Those discrepancies could have caused either the crew or automatic control systems to make wrong decisions about howfast to fly the plane as it headed into heavy weather.Similar malfunctions were key factors in a pair of little-noticed 1996 crashes. In one, off the coast of the Dominican Republic, investigators found that a Pitot tube had been stopped up by an insect infestation. In the other, near Lima, an inquiry determined that maintenance staff forgot to remove masking tape placed over sensor ports. In the case of Flight 447, messages received from the plane "indicate inconsistency between measured airspeeds-which means how fast the plane was going is not clear," Airbus spokeswoman Mary Anne Greczyn told NEWSWEEK. "We don't yet know why."