Air France captain absent when descent began

Updated at 11:53 a.m. ET

PARIS - An Air France jet carrying 228 people stalled before plunging from 38,000 feet and crashing into the Atlantic Ocean in less than four minutes, accident investigators said Friday.

Black box recordings from the plane reveal the final minutes of the doomed plane, as two co-pilots struggled to regain control over the plane as it swayed from side to side and fell at almost 11,000 feet per minute.

Everyone aboard Air France Flight 447 from Rio de Janeiro to Paris was killed on June 1, 2009.

Read the investigation's initial findings (PDF)
Terrifying last minutes of Air France flight 447
Black boxes from Air France 447 crash intact

The initial findings also showed the captain was out of the cockpit for a routine rest period and arrived more than a minute after the emergency began.

The plane was passing through bad weather in the mid-Atlantic when the problems began.

More than eight minutes before the crash, the co-pilot at the controls, one of three members of the flight crew, advised the cabin crew "you should watch out" for turbulence ahead. He said the plane could not climb out of the cloud layer where the turbulence was happening because it was not cold enough.

Soon after, the plane's autopilot and auto-thrust shut off, the stall alarm sounded twice and the co-pilot at the controls, 32-year-old Pierre-Cedric Bonin, took over manual control

The plane climbed from 35,000 to 38,000 feet, but stalled and began to fall.

The flight sensors that measured airspeed were frozen.

"Now they're in trouble because they're slowing the plane down, slower than it should be flying at all and they put it into a high-speed stall," CBS News travel editor Peter Greenberg said on "The Early Show" Friday. "The nose goes up to about 16 degrees and the plane starts climbing. But at that altitude and that speed it loses speed very quickly and ... at 38,000 feet it starts to drop and it's dropping at some points up to 10,000 feet a minute."

Greenberg said the fact that the captain wasn't present at the start of the emergency was "not relevant at all to the situation."

The two co-pilots wrestled with the controls for about 3 1/2 minutes in a bid to stop the Airbus A330 from spiraling into the sea, the report said.

It report did not analyze the data or cockpit conversations or assign blame. The report also did not suggest whether the Pitot tubes, the plane's speed sensors — which investigators have said likely played a role — were the main culprits, or whether the temporary absence of Capt. Marc Dubois from the cockpit had any impact on the quickly unfolding events.

So far, the search teams have not found the plane's Pitot tubes. Co-pilot Pierre-Cedric Bonin, then 32, was at the controls as the plane went down, sitting to the right of a second co-pilot, David Robert, 37. Pilots on long-haul flights often take turns at the controls to remain alert. Dubois returned to the cockpit, but did not take back the controls.

The speed sensors have been a focal point of the investigation. In March, Air France was charged in a French court with manslaughter in the deaths of the people on board. That investigation is looking into whether the airline knew the sensors were defective.

Airbus faces charges over 2009 Rio-Paris crash

The flight recorders were found along with bodies in the latest search of the ocean depths last month. A full report on the crash is not due until next year.

Greenberg also noted that the initial findings don't answer a potentially critical question about the crash: Why the plane's tail was found intact many miles away from the main debris field.

"The real question is did that tail come off before the plane hit the water? And when did it come off if it came off at all? That's what they're going to look at now."