Messages from Air France flight point to rudder problem
Meanwhile, the head of the parent company of the jet’s manufacturer said yesterday that the plane likely crashed for a variety of reasons.
The aviation industry official, who has knowledge of the Air France investigation, said on Saturday that a transcript of the messages posted on the website EuroCockpit is authentic but inconclusive.
The flight was carrying 228 people from Rio de Janeiro to Paris on May 31 when it ran into fierce thunderstorms.
One of the 24 automatic messages sent from the plane minutes before it disappeared points to a problem in the “rudder limiter”, a mechanism that limits how far the plane’s rudder can move. The nearly intact vertical stabiliser – which includes the rudder – was fished out of the water by Brazilian searchers.
“There is a lot of information, but not many clues,” the official said.
The official said jets like the Airbus A330 automatically send such maintenance messages about once a minute during a plane’s flight. They are used by the ground crew to make repairs once a plane lands.
Martine del Bono, spokeswoman for the French investigative agency BEA, which is in charge of the crash probe, and Airbus spokesman Stefan Schaffrath declined to comment.
If the rudder were to move too far while travelling fast, it could shear off and take the vertical stabiliser with it, which some experts theorise may have happened based on the relatively limited damage to the stabiliser.
The industry official, however, said the error message pertaining to the rudder limiter did not indicate it malfunctioned, but rather that it had locked itself in place because of conflicting speed readings.
Investigators have focused on the possibility that external speed monitors – called Pitot tubes – iced over and gave false readings to the plane’s computers.
“The message tells us that the rudder limiter was inoperative,” said Jack Casey, an aviation safety consultant. “It does not give you any reason why it is not working or what caused it, or what came afterward.”
In Paris, the head of Airbus’ parent company said there is probably more than one reason for the crash of Flight 447. “In such an accident, there is not one cause,” European Aeronautics Defence and Space Company chief Louis Gallois said. “It’s the convergence of different causes creating such an accident.”
So far, there is no evidence of an explosion or terrorist act, just clues that point to systemic failures on the plane. Experts have said the evidence uncovered so far points to at least a partial midair breakup of the Airbus A330.
