RIO DE JANEIRO — Investigators trying to determine why Air France Flight 447 broke apart in a violent storm over the Atlantic are looking at the possibility that speed sensors — an external instrument key to collecting speed data — failed in unusual weather, two aviation industry officials said Thursday.
The plane went down off Brazil’s northeastern coast, killing all 228 people aboard.
Officials with knowledge of the investigation and independent analysts stressed they don’t know why a plane that seemed to be flying normally crashed just minutes after the pilot messaged that he was entering an area of extremely dangerous storms.
Investigators will have little to go on until they recover the Airbus A330’s “black box” flight data and voice recorders, now likely on the ocean floor miles beneath the surface.
Other hypotheses — even terrorism — haven’t been ruled out, though there are no signs of a bomb. Officials have said a fuel slick on the ocean’s surface suggests there was no explosion, but the slick’s origins also have been cast into doubt.
Two officials told The Associated Press that investigators are looking at the possibility that an external probe that measures air pressure might have iced over.
The external probe, called a “pitot tube,” has heating systems to prevent icing. But if those systems somehow malfunctioned, the tubes could quickly freeze at high altitude in storm conditions.
If the instruments were not reporting accurate information, the jet could have been traveling too fast or too slow as it entered turbulence from towering bands of thunderstorms, according to the officials.
Jetliners need to be flying at just the right speed when encountering violent weather, experts say — too fast and they run the risk of breaking apart. Too slow, and they could lose control.
Brazil’s Navy and Air Force, meanwhile, issued statements saying that despite earlier reports, no wreckage yet been recovered from the Airbus A330, though some had been spotted. Some items that were recovered proved to be trash.
Also Thursday, more than 500 people packed the historic Candelaria church in the center of Rio de Janeiro for a Mass for the victims.
