Pilot error is looking to be the cause of the 2009 crash into the Atlantic that killed all 228 people on board. The authorities won't say that conclusively, but a report released by French investigators suggest a confused cockpit, as pilots tried dealing with their stalled-out Airbus A330. As has been theorized, the problems originated with malfunctioning airspeed probes that led to the disconnection of the autopilot and the loss of various piloting protection systems. In other words, they were on their own - and after a second stall warning, the pilot at the controls did something inexplicable: He pulled up the jet's nose, thus worsening the stall (imagine a plane almost halfway up to vertical at an airspeed of about 100 miles per hours, far too slow for the plane to keep flying). Anybody who has taken flying lessons knows that when there is any doubt about having enough airspeed, you are supposed to push the nose down. That's why the actions are so weird. The jet fell at a rate of 10,000 feet a minute, or roughly 15 stories a second. Complicating matters was that the captain was on a rest break when the problem first developed. From the WSJ:
The report paints a somewhat unflattering picture of a seemingly confused cockpit, with the crew making extreme inputs to their flight controls and the engines spooling up to full power and later the thrust levers being pulled back to idle. At one point, according to the report, both pilots sitting in front of the controls tried to put in simultaneous commands. The plane only accepts one of them.
Here's some perspective from Wil Hylton's recent article on the crash in the NYT magazine:
During the period of manual control, the margin of error is thin. For a passenger jet like the A330, the ideal cruising speed is about 560 miles per hour. If you go much faster, the center of lift moves back on the wing, pushing the nose down and increasing velocity, until you soon approach the speed of sound. At that point, shockwaves develop on the wings, interrupting the flow of air and reducing lift. The nose of the plane then gets forced into a dive that the pilot may not be able to pull out of. Then again, if you go too slow, the airplane stalls and falls. A plane must maintain a minimum speed to generate lift, and the higher it travels, the faster it must go. At 35,000 feet, the gap between too fast and too slow narrows ever closer. Pilots call it coffin corner.
The pilot of a jumbo jet told Business Insider more information is needed to determine precisely what happened, but that today's report suggests an extraordinary set of circumstances:
With the autopilot off, they would be doing everything they could to recover the plane. They knew the airspeed was slow - that is why they had the throttles at max. Unfortunately, the plane was probably already stalled or close to it at this point. And with severe turbulence it wouldn't take much to stall the plane out. Should they have been able to recover the plane (in those conditions) I don't know. With the nose up 40 degrees it's difficult to say. How effective were the elevators if at all. I'm sure a computer program could determine this but in the heat of the moment who knows. I didn't read where the other pilot attempted to take control of the aircraft until the very end - probably because the flying pilot capitulated suggesting to me that the non-flying pilot would have been doing the same thing. Interestingly, with the aircraft nose up 40 degrees I'm curious how the Captain even got back into the cockpit. Couldn't have been easy.
The most gruesome thought, of course, is what did the passengers know and when did they know it? From Hylton's piece:
After a while, [Dr. Francisco Sarmento, the doctor who presided over the Flight 447 autopsies], flipped off the projector and pushed away from the table in his chair. "Ninety percent of the passengers had fractures in the arms and legs," he said. "Many of them also had trauma in the chest, in the abdomen, in the cranium. We didn't find anybody burned." He leaned forward in his seat and wrapped his arms around his knees. "They were like this," he said, holding the crash position and looking into my eyes. Then he sat up quickly and held his hand flat above the table. "When they hit," he said, slamming it down, "fractures. I believe the pilot tried to land in the water. This is consistent with the fractures. But when the bodies arrived, the lungs were already in a state of decomposition. We didn't have conditions to see if anyone drowned." This hung in the air for a moment as I considered what he was suggesting. "So it's possible that some of them were still alive?" I asked. Sarmento nodded. "Most died on impact," he said. "Some could have survived."