As investigators try to locate the missing Malaysia Airlines Boeing 777 that mysteriously vanished without a trace last weekend, pundits are also at a loss as they try to come up with theories to satisfy their editors and producers. Since the flight went missing on Saturday, talking heads and writers have desperately tried drawing parallels between this incident and the 2009 crash of Air France 447, but the two events are likely unrelated aside from the fact that both happened over water.
Air France 447 was a daily flight that flew from Rio de Janeiro to Paris, an 11 hour flight that, during the spring and summer months, often routed the aircraft near rough thunderstorms that occur in the intertropical convergence zone (ITCZ). The ITCZ is an area of wind convergence near the equator that often produces heavy thunderstorm activity.
On the evening of June 1, 2009, the Airbus A330 operating as Air France 447 entered heavy thunderstorms in the ITCZ, leading to what investigators suspect was the buildup of ice on the aircraft's pitot tubes. A pitot tube is a heated metal tube that sticks out from the fuselage of the aircraft. Wind outside the aircraft enters the tube and allows the sensors onboard to measure the plane's airspeed. Most aircraft have several of these tubes as a redundancy feature in case one (or more) fails.
Investigators believe (caution: PDF file) that the Airbus A330's pitot tubes iced over as the aircraft flew through the upper levels of the thunderstorms it encountered over the open Atlantic Ocean that night, effectively preventing the aircraft's computers from displaying the correct airspeed. This caused the autopilot to disengage; as a result, the aircraft began to stall — the plane slowed so much that it disrupted the airflow over the wings, leading to insufficient lift — the pilots reacted incorrectly, and the plane fell belly-first into the Atlantic.
Why was Malaysia Airlines 370 probably nothing like this? The weather was completely clear that night.
Dr. Cliff Mass explained it pretty well over at his weather blog a few days ago. Skies were clear and winds were calm across southeast Asia that night. There was absolutely no foul weather along the flight path of Malaysia Airlines 370 when it went missing. Icing (or any other weather phenomenon) is very unlikely to have contributed to the crash/disappearance of this flight.
The parallels drawn between Air France 447 and Malaysia Airlines 370 are just pundits pulling anything they can out of the air in order to talk about something when the cameras turn on or copy is due. Barring any indication that an uncontrolled stall caused a potential crash, the only thing the two flights have in common is that they (probably) crashed into the ocean.
[Image via Air France]