May 27, 2011 -- It took three minutes and 30 seconds for Air France flight 447 to descend 38,000 feet before it plunged into the Atlantic Ocean, killing 228 people onboard, according to France's Bureau of Investigation and Analysis.
The newly released update on the investigation chronicles the final harrowing minutes aboard the June 1, 2009, flight.
The Airbus A330 had taken off from Brazil and was bound for Paris when, nearly four hours into the flight, it apparently encountered heavy icing. The icing caused the speed sensors to malfunction, which meant the onboard computers were receiving inaccurate and conflicting speed readings. The readings caused the plane's autopilot and autothrust to disengage.
The captain was on a scheduled break when the autopilot was disengaged, leaving the two co-pilots at the controls.
"They flew into the top of one of these thunderstorm buildups," said ABC News' aviation consultant John Nance. "The air-speed goes erratic [and] the airplane says, 'I can't fly myself if I don't have good air-speed indications,' and it clicks off.
"[This] leaves the confused pilot with a handful of airplane," he added. "He doesn't know what [indicators] to believe."
What the two co-pilots did next baffles aviation experts. They jerked up the nose of the plane, climbing to 38,000 feet, reducing airflow over the wings and stalling the aircraft. There were repeated warnings in the cockpit indicating a stall, but the pilots did not lower the nose of the airliner to recover from it.
"Once your airspeed has proven unreliable, a stall warning is all about airspeed, and if you no longer trust it, then you're no longer going to trust that it's telling you the truth -- that you're really stalled," said Nance. "What they were doing was trying to fly the airplane physically while searching for which instruments to believe and not to believe. That's where they got themselves in fatal trouble."
The co-pilots repeatedly tried to call the captain back to the cockpit and he rushed in to help a minute and a half after the autopilot had been disengaged.
However, the crew never pulled out of the stall and the plane fell, nose up, rolling from side to side as much as 40 degrees until it hit the water.
"They end up stalling the airplane," Nance said, "but they don't recognize that the airplane is in a stall and they don't do the appropriate things to get it out of a stall ... because they don't believe anything that the airplane is telling them, at that point."
Nance believes that if it had been a calm and clear day, the pilots likely could have resolved the issue quickly, but in the confusion of being bounced around in turbulence they were unable to diagnose the problem. In the end, he said, it's easy to blame the pilots -- but in reality, it comes down to training.
"What we have here is a major training issue, training and proficiency," Nance said, "and I would think one of the major points that has to come out of this is that pilots -- not just at Air France, but all over the planet -- need to be massively trained.
"This airplane was flyable," he added. "There was no reason for this airplane to crash other than pilot confusion."
For the families of those lost, the news is difficult to hear.
John Celmes' brother died in the crash, and he hopes the findings will at least help prevent another accident like this one.
"It is very emotional," Celmes said. "But again, I think pretty much on this point all the families agreed that it is something that we need to have, we need to know."