Blackbox findings of the Air France Rio-Paris flight indicate that pilots wrestled with the controls of the aircraft for more than four minutes before it plunged into the Atlantic.
The 2009 emergency began with a stall warning two and a half hours into the Rio-Paris flight and shortly after the captain briefly left the cockpit at the start of a routine rest period.
The Airbus A330 jet climbed to 38,000' and then began a three and a half minute descent, rolling from left to right, with the youngest of three pilots handing control to the second most senior pilot one minute before the crash.
The timeline was given in a note by France's BEA crash investigation authority, which said it was too early to give the causes of the crash ahead of a fuller report in the summer.
One of the instruments showed 'a sharp fall' in airspeed as the aircraft entered a zone of turbulence, the stall warning sounded and the autopilot disengaged.
An interim inquiry, conducted prior to the raising of the data recorders from the ocean floor earlier this month, had pointed to an icing problem with the probes measuring air speed, known as Pitots, but there was no definitive conclusion as to the cause of the crash.
Pilot's unions and some of the victims' families have accused the airline of reacting too slowly to safety warnings, but both Airbus and Air France insist they reacted properly.
Since the accident, Air France has replaced the Pitots on its Airbus fleet with a newer model.
Both companies are being probed for alleged manslaughter in connection with the crash
The captain had left the cockpit less than ten minutes before the plane encountered trouble, and had discussed with the co-pilots that they were flying into an area of increased turbulence.
Once the trouble began the co-pilots tried several times to contact the captain before he returned to the cockpit roughly one minute and thirty seconds after the stall warning sounded.
The captain did not retake the controls, with the co-pilots flying the plane until the end, the investigators said during a conference call.
The BAE report said 'the composition of the crew was in accordance with the operator's procedures.'
The captain would normally take a rest during the flight and leave the two co-pilots at the controls.
Three Irish doctors were among the dead.
Timeline of minutes up until the crash
The following information is taken from BEA's English translation of the investigation update released today.
The captain and two co-pilots were on board.
The BEA refers to the pilot flying the plane, in this case for the majority of the time analysed the more junior of the co-pilots, as 'PF', while a pilot not at the controls is called 'PNF'.
31 May 2009: 22:29 Take-off.
1 June:
01:55 The captain woke the second co-pilot, said 'He's going to take my place' and left the cockpit.
02:06:04 The PF called the cabin crew, telling them to watch out because turbulence was coming up. 'It'll move about a bit more than at the moment,' he said.
2:08:07 The PNF said 'you can maybe go a little to the left' and the plane began a slight turn to the left. Turbulence increased slightly and the crew decided to reduce speed.
From 2:10:05 The autopilot and auto-thrust disengaged and the PF said, 'I have the controls.'
The airplane began to roll to the right and the PF tried to raise the nose up and to the left.
The stall warning sounded twice in a row. Recorded parameters show a sharp fall in speed.
2:10:16 The PNF said 'so, we've lost the speeds' then 'alternate law ...' The plane started to climb.
The PF tried to bring the nose down and rolled alternatively left and right.
From 02:10:50 The PNF tried several times to call the captain back.
02:10:51 The stall warning was triggered again.
The PF continued trying to pull the nose up. Altitude reached its maximum of about 38,000 ft.
02:11:40 The captain re-entered the cockpit. In the following seconds, all the recorded speeds became invalid and the stall warning stopped.
The altitude was about 35,000' but the plane was descending at about 10,000' per minute.
02:12:02 The PF said 'I don't have any more indications,' and the PNF said 'we have no valid indications.'
Around 15 seconds later, the PF pulled the nose down. The angle of attack decreased, the speeds became valid again and the stall warning sounded again.
02:13:32 The PF said the plane's altitude was nearing 10,000 feet.
About 15 seconds later, simultaneous inputs by both pilots on the sidesticks were recorded and the PF said 'go ahead, you have the controls.'
02:14:28 The recordings stopped.
