“Recorders found two years later explained how, but not why.”
There were many human factors such as the captain only having had and hour’s sleep and the poor relations between the two copilots, left alone, that contributed.
Air France Flight 447, June 1, 2009
Extract from beginning:
The arrivals boards at Paris’s Charles de Gaulle Airport indicated Air France Flight 447 from Rio de Janeiro as “Delayed,” but with the delay becoming interminable it became obvious that something was seriously wrong. Finally, the airline had to admit the aircraft with 216 passengers and 12 crew had disappeared between Brazil and Africa.
With no Mayday call, and the Airbus A330 lost in an area not covered by radar, the only real clue as to what had happened was a short stream of cryptic ACARS maintenance messages sent from it by satellite to Air France in Paris. These showed the computers had switched to alternate law meaning the protections preventing the pilots flying outside the safe operating envelope were disabled.
A few days later the Brazilians began recovering small amounts of wreckage, including the vertical stabilizer (tail fin), from the South Atlantic Ocean surface. They also retrieved some fifty bodies, including that of the captain.
A French submarine and vessels trawling with sideways-scanning detectors began searching for the locating signal of the digital flight data recorder (DFDR) and cockpit voice recorder (CVR). They continued until the batteries in the locators would have run down a month later. It was claimed this search was unsuccessful because the water was almost two and half miles (four kilometers) deep and the ocean floor very uneven in places.
Neither the wreckage nor the bodies showed any traces of explosives, so a bomb was ruled out. The aircraft had clearly hit the water with considerable force, but with so little evidence the investigation was in a limbo. Speculation was rife. Did the A330 have some inherent defect?
Two years later, when the search was about to be abandoned, the organizers sought the help of US experts using mathematical probability theories to analyze searches where the object has initially been missed. Using their input, searchers rescanned areas where the wreckage might have been and soon found it thirteen thousand feet (four thousand meters) below the surface of the ocean.
The cockpit voice and flight data recorders were recovered intact, and to Airbus’s relief revealed there was nothing intrinsically wrong with the aircraft. Though only made public much later in the course of the judicial inquiry the captain had been recorded telling the junior first officer he had only had an hour’s sleep the night prior to the flight and admitting it was “not enough.”
End of extract.