The Air France disaster, explained

Glenn Pew has an article at AVweb.com about Air France 447:

The pilots of Air France Flight 447 flew the aircraft into a deep stall at 38,000 feet, never verbally acknowledged or corrected that condition, and the aircraft fell for more than three minutes at nearly 11,000 feet per minute into the Atlantic, killing all aboard, investigators said. The jet maintained a nose up attitude, along with an angle of attack greater than 35 degrees, throughout a descent rate that translates to more than 122 miles per hour of vertical drop. "At no point on the cockpit voice recorder is the word stall ever mentioned," Chief Investigator Alain Bouillard said in an interview. The autopilot and auto-throttle disengaged and the pilots recognized failure of the Airbus A330's speed sensors. The pilots took manual control and the aircraft climbed. A stall warning sounded as the jet ascended rapidly from 35,000 to 37,500 feet and, by 38,000 feet, three stall warnings had activated. Less than two minutes after the autopilot disconnected, the aircraft was at approximately 35,000 feet, with full takeoff thrust selected; the angle of attack had exceeded forty degrees and jet was falling at about 10,000 ft/min.
The captain was not present in the cockpit as the incident began. The flight deck crew was flying at night over the ocean near storms where they expected turbulence. What they faced was an aircraft that suddenly disengaged both the autopilot and auto-throttles, and cockpit displays that delivered mismatched and rapidly changing airspeed values that ranged from at least 275 to 60 knots. Within seconds, the non-flying pilot stated: "So we've lost the speeds." Then he said: "Alternate law." Those two words mean, among other things, that the aircraft's angle-of-attack protections have been shut down. Before the captain entered the cockpit, the pitch and angle of attack of Flight 447 had both reached sixteen degrees as it was hand-flown. The horizontal stabilizer had passed from three to about thirteen degrees nose-up. The throttles had been set at full takeoff thrust and the aircraft had stalled. It was less than two minutes since the autopilot had disengaged.
As the captain entered the cockpit, the aircraft's systems received airspeed values they deemed invalid, leading the airplane's systems to automatically shut off the stall warnings. The aircraft was still in full stall with the nose up, falling at 10,000 ft/min. Almost one minute into the stall, the pilots reduced engine thrust and temporarily made nose-down inputs that were not enough to break the stall. As the jet continued to fall, it rolled at times up to forty degrees and turned more than 180 degrees to the right. Data shows that the pilot flying held the sidestick at the full left and nose-up stops for the entirety of one thirty-second span, and that the airliner remained stalled until impact.
There were as many as three pilots in the cockpit through the majority of the descent. The pilot flying as the event unfolded was the least experienced of the crew, with three thousand hours of flight time. He was right-seat at the time. The flight's captain had almost eleven thousand hours of experience. He was not in the cockpit as the incident began. The cockpit crew attempted to call him to the flight deck several times during the first minute after the airspeed sensors failed. He joined them less than two minutes after the autopilot disconnected. A second pilot, flying left seat, was given the controls in the flight's final minute. Aside from that information, BEA, the investigating agency, did not publish any cockpit conversation that took place during the last minute of the flight.
The aircraft impacted the water at 16.2 degrees, nose-up, with a roll angle of 5.3 degrees to the left. The aircraft heading was 270 degrees (nearly opposite the planned route of flight) and the ground speed was 107 knots. The last recorded vertical speed was 10,912 ft/min.

Wil Hylton has an article in The New York Times on the same subject:

Late on the morning of 3 April, the expedition ship Alucia rocked violently on the South Atlantic Ocean in the middle of a squall. On the aft deck, the crew huddled together in rain slickers and gazed across the heaving seas to a yellow blur on the horizon. This was an unmanned reconnaissance submarine carrying 15,000 photographs that they were nearly desperate to see. But it had buoyed to the surface just as the squall sprang up, and with thirty-knot winds and four-foot swells that splashed over the stern, it was too dangerous to retrieve the sub. So they watched and waited.
For eight days, the Alucia had been trolling the ocean near a spot known as the LKP, or the Last Known Position of Flight 447, the Air France jet that vanished in June of 2009, about halfway between South America and Africa. In the nearly two years since, three other search teams went looking for the wreckage, but this was the Alucia’s first try. The ship carried three Remus 6000 submarines, some of the most advanced underwater search vehicles on earth, which swept the seafloor in twenty-hour runs, then surfaced to deliver sonar imagery to the Alucia’s scientific team, who pored over the data in twelve-hour shifts around the clock. So far, they had not found the plane, but the day before, one scientist pointed at something unusual on the monitor and said: “What about this?” And ever since, the air on the Alucia was charged.
Everyone knew the stakes. This wasn’t a scan of the Sargasso Sea or a study of salinity samples. The families of 228 passengers were restless for results. The search had already taken two years and cost more than $25 million. Another $12 million was committed to the Alucia this year, but French investigators had quietly decided that this year would be the last. If the Alucia did not find the plane, no one ever would.
As expedition leader, Michael Purcell was equal parts colleague and boss, with a raspy voice and a sonic laugh and a playful sarcasm, but he knew the Remus subs as well as anyone. Looking at the fuzzy mark on the monitor, he knew they had found something unnatural. It was too long and straight to be geologic. It was unlike anything else on the seafloor. On the other hand, if it wasn’t Flight 447, Purcell knew the disappointment would be palpable. As he prepared the photographic sub to return to the bottom for an eighteen-hour mission, Purcell whispered to another scientist: “I’m 95 percent sure that’s it, but man, if it’s not, it’s going to be a long two and a half months.” The sub went down at 9:45 p.m. At 2 a.m., Purcell was still awake in his cabin. He picked up his journal. “Tired but not sleepy,” he wrote. “May have found the plane today. Everyone is on edge.” Four hours later, Purcell was up with the sun, and by late morning he was on deck with the crew, watching the Remus bob in the distance. A little after 1 p.m., they pulled the sub onboard and attached two thick cables to upload its data into the computers in the mission-control room. They drew the curtains around the room, so non-scientific crew members could not see in, and yanked the satellite uplink offline, so no one could leak the news. Then they crowded around the computer monitor as the first images of Flight 447 came onscreen: engines, landing gear and sections of fuselage, all unmistakably vivid on the ocean floor. But as they turned the satellite back on and began sending the first photos to air-crash investigators in France, the deeper implications of their discovery were just beginning to surface.
The vanishing of Flight 447 was easy to bend into myth. No other passenger jet in modern history had disappeared so completely, without a Mayday call or a witness or even a trace on radar. The airplane itself, an Airbus A330, was considered to be among the safest. It was equipped with the automated fly-by-wire system, which is designed to reduce human error by letting computers control many aspects of the flight. And when, in the middle of the night, in the middle of the ocean, Flight 447 seemed to disappear from the sky, it was tempting to deliver a tidy narrative about the hubris of building a self-flying airplane, Icarus falling from the sky. Or maybe Flight 447 was the Titanic, an uncrashable ship at the bottom of the sea.

Rico says there's a bunch more here...