Jet plummeted for three minutes before hitting sea
Passengers on an Air France flight plunged for three-and-a-half minutes before crashing into the Atlantic, killing all on board, after it lost speed and stalled while the main pilot was resting, the first evidence from black boxes has revealed.
AF447's junior pilot battled to save the Rio de Janeiro to Paris flight, as the flight's second pilot tried to rouse the captain shortly after the plane begun its fateful descent in a tropical storm.
According to flight recorder data, the younger of the two men, Pierre-Cedric Bonin (32), angled the jet's nose higher, a position the aircraft maintained until its final impact, after the pilots received inconsistent speed readings.
Aviation experts asked why the pilot kept giving nose-up inputs when the plane was in a stall, instead of putting the nose down to recover speed and regain control.
All 228 people on board -- including crew -- died after the Airbus hit the Atlantic at a speed of 180 feet per second in the worst disaster in Air France's history.
David Robert (37), the second pilot, took over the controls from his junior colleague after making a number of anxious calls for their more experienced captain -- who had left the cockpit for a routine rest period -- after the autopilot suddenly cut out four hours after take-off.
Captain Marc Dubois returned a minute-and-a-half later, but never retook control of the plane -- instead leaving the flying to his assistants. Capt Dubois (58) had clocked up 11,000 flying hours over his airline career, while his more junior counterparts had 6,500 and 2,900 hours respectively. Air France praised the "three skilled pilots" yesterday, saying they "demonstrated a totally professional attitude and were committed to carrying out their task to the very end".
It was standard procedure for the main pilot to take a rest during long-haul flights, a spokesman added.
The fresh data came after the black boxes were recovered from 12,800ft beneath the waves and returned to Paris this month, two years after the jet disappeared on June 1, 2009.
Releasing preliminary findings, France's accident investigation office, the Bureau d'Enquetes et d'Analyses (BEA), said they showed the co-pilots decided to turn slightly to the left to avoid a zone of turbulence, warning cabin crew to expect the plane to "move around".
Two minutes later the autopilot disengaged, the instruments began showing that the speed slowed and the engine stall warning alarm began to sound.
The BEA said the pilots received inconsistent speed readings for around a minute, with one pilot saying: "We have no valid indications." This suggests there was a problem with the plane's speed-sensing Pitot tubes that a preliminary investigation had indicated might have contributed to the crash.
The pilots responded by pulling up the aircraft's nose, triggering a stall warning.
According to the BEA, the co-pilots continued to increase the angle of climb, rising rapidly from 35,000ft to 37,500ft. When a third stall warning sounded, they continued to pull back on the controls and rose to about 38,000ft, at which point the plane entered a stall.
With the plane's nose still pointed up about 15 degrees, the jet began falling at around 10,000ft a minute, rolling left and right. Almost one minute into the stall, the pilots reduced engine thrust and tried to lower the nose. Airspeed indications returned and the alarm sounded again as the aircraft picked up some speed, but the plane never recovered from the stall.
Air France and Airbus are facing manslaughter charges following the crash and a judicial investigation led by Paris judges is under way.
The BEA said its preliminary findings from the flight recorders had not yet established a cause for the accident, which would come only after "painstaking" analysis of the data. A second report is due in July.