According to German news magazine Der Spiegel, the Captain of AIR FRANCE Flight 447, the Airbus A330 that crashed in the Atlantic on June 1, 2009, was not in the cockpit when the plane ran into trouble. Today's report said the Captain could be heard on the black box recordings rushing into the cockpit when the plane encountered bad weather. while enroute from Rio de Janeiro, Brazil, to Paris, France. The magazine says that he gave instructions to the Co-Pilots on how to save the Airbus. Until now it had been thought that the crew of Flight 447 flew directly into a bad weather front as other planes flew around it. But, according to Der Spiegel, information from the Flight Data Recorder, which was recently found with the Cockpit Voice Recorder, amid the plane wreckage at the bottom of the ocean, proves otherwise. The flight path showed clearly that the crew had tried to chart a smooth course through the storm clouds. "It looked initially as if they had been successful, because there were no indications that they encountered increased turbulence," says the magazine. What the data did show, however, was that ice crystals caused by the bad weather had clogged up the Pitot Tubes, an instrument used to measure airspeed. After the tubes malfunctioned, the Airbus lifted steeply, which would caused the engine to stall and the plane to crash. The investigation into the crash is being carried out by the French Transport Ministry’s Bureau of Enquiry and Analysis (BEA). The BEA, which had no comment on the magazine report, has said it will release details of the circumstances of the crash on May 27, but that the cause of the crash will take longer to establish.
"After the tubes malfunctioned, the Airbus lifted steeply, which would cause the engine to stall and the plane to crash." This isn't necessarily so. (Bad bit of reporting Der Spiegel.) A compressor stall could lead to an engine failure but there is no evidence yet that confirms any even occurred or that the engine[s] was not running at impact. The BEA’s interim report (2009) states that AF447 was flown into the water while deeply stalled. The 'stall' here meaning aerodynamic wing stall, not an engine stall. Since the Airbus throttles do not physically move inflight, the pilots may not have realized they needed to increase thrust once their autothrottles disconnected. Airbus test pilots have demonstrated that the Unreliable Airspeed Memory Items of setting 3-5° pitch and a power 85% N1 keeps the aircraft at a safe speed from stall without a reliable airspeed indicator but failing to take action can cause the aircraft to suffer a critical stall. This theory is presented in the NOVA special Crash of Flight 447. If you have not seen it, it can be viewed online. As always, great job on the blog!
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