Air France Mystery Deepens

There were reports that Brazilian authorities had found debris from the downed plane, but now the French authorities are denying that. At this point a miles long oil slick seems to be the only possible connection to the missing jet. All options as to what might have happened are still on the table, from terrorism to a weather-related break-up.

A theory that makes a lot of sense to me is detailed in this report:

Investigators are looking into whether malfunctions in instruments used to determine airspeed may have led the plane to be traveling at the wrong speed when it encountered turbulence from towering thunderstorms over the Atlantic Ocean.

Two aviation industry officials told The Associated Press on Thursday that investigators were studying the possibility that an external probe that measures air pressure may have iced over. The probe feeds data used to calculate air speed and altitude to onboard computers. Another possibility is that sensors inside the aircraft reading the data malfunctioned.

If the instruments were not reporting accurate information, the jet could have been traveling too fast or too slow as it hit turbulence from violent 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.

But Gerard Feldzer, a former Air France pilot who flew A330s from 2000 to 2004, cautioned against drawing conclusions about the cause of the crash.

"We don't know whether there was depressurization. Perhaps a quarter of an hour later it was resolved and it (the cause of the crash) was something completely different."

Among the many speeds a pilot needs to memorize for his aircraft is "maneuvering speed", the maximum and recommended speed for penetrating areas of turbulence. Flying into severe turbulence above that speed could result in structural failure as wings are loaded behind their design capabilities. A failure like that would probably cause the plane to hit the water in a number of pieces and I would expect that light debris would be all over the surface. I'm really surprised they haven't found anything yet.