The French air accident investigation agency, the Bureau d’Enquetes et d’Analyses (BEA), on Friday issued its third interim report into the loss of Air France Airbus A330-200 F-GZCP, which crashed into the South Atlantic on June 1, 2009. The aircraft had been operating flight AF447 from Rio de Janeiro to Paris, and 228 people, including a South African, lost their lives.
F-GZCP had three flight crew on its last flight, one Captain and two co-pilots, and the Captain left the flight deck to rest some nine minutes before the emergency struck. In its latest report, the BEA found that the Captain had left no operational instructions for the co-pilots when he left the cockpit and there was no explicit task sharing between the co-pilots.
Furthermore, the disparity in indicated air speed (IAS) between the primary flight display and the integrated standby instrument system, which started the sequence of events that led to the crash (by automatically disengaging the autopilot and switching the aircraft’s computers from normal to alternate law), was “likely” caused by “the obstruction of the Pitot probes in an ice crystal environment”.
On top of this, although the two co-pilots identified what was happening, neither initiated the “Unreliable IAS” procedure and neither had been trained for this procedure and manual aircraft handling at high altitude (the aeroplane was flying at about 35 000 ft).
Neither made any comments about the changes in the aircraft’s pitch and vertical speed and when it entered a stall (which triggered the very audible stall warning, which at one point sounded continuously for 54 seconds) neither made any reference to it nor formally recognised that F-GZCP was stalling.
The Captain returned to the flight deck some one and a half minutes after the autopilot disengaged. As he did so, the aircraft’s angle of attack reached 40 ˚ (but pitch did not exceed 15 ˚), while forward speed had dropped so low (less than 60 knots) that the stall warning ceased. But the angle of attack was never directly displayed to the flight crew.
No announcements were ever made to the passengers. No emergency message was transmitted by the crew.
Three minutes and six seconds after the Captain returned to the cockpit, the plane hit the sea. The wreckage was not found until April 3 this year.