Air France Flight 447: Mayday and the Search for the Recorders

This Mayday episode tells the story of Air France Flight 447 from the investigators' side. For most of its length the cause is unknown, so the episode follows the theories the BEA had to rule out and the long search for the flight recorders before it reconstructs the final minutes.

A flight that never arrived

The episode opens with the A330 crossing the Atlantic at 35,000 feet. The 58-year-old captain, Marc Dubois, is in command, with First Officer Pierre-Cédric Bonin, 32, and relief pilot David Robert, 37. After leaving Brazilian radar cover the aircraft is due to report to controllers in Senegal, but it never does. The only signals are 24 automatic maintenance messages sent by the aircraft in its final minutes. By the time the scheduled arrival in Paris passes, the airline is telling families that the aircraft has almost certainly come down at sea.

Theories without evidence

With no recorders, the BEA works from the maintenance messages, the floating debris and the weather. The episode looks at the possibility of a bomb, which was taken seriously at first, and at severe turbulence and lightning. The messages point to inconsistent airspeed readings, which leads investigators to the pitot probes. Air France and other airlines were already replacing this model of probe because of repeated icing, but a frozen probe on its own should not bring down an airliner. The tail fin, recovered from the sea, shows that the aircraft hit the water belly first and largely intact, rather than breaking up in the air.

The search

The locator beacons on the recorders could only transmit for about 30 days. The first searches listened for them over a huge area and heard nothing. The episode describes the seabed as mountains and valleys and compares the search to looking for something in the Alps. After several campaigns, the wreckage was found in April 2011. The episode gives the depth as almost 4,000 metres. The recorders were brought up in May 2011, and their memory cards were readable.

What the recorders showed

The episode then rebuilds the final flight. The captain leaves for his rest, the aircraft enters cloud full of ice crystals, the airspeed readings drop and the autopilot disconnects. Bonin pulls the nose up. The aircraft climbs, loses more than 90 knots of speed in under a minute and stalls. The stall warning sounds again and again, but the crew do not act on it. The captain returns about 90 seconds after the crisis began and does not understand what is happening either. By the time the crew work it out, they are too low to recover.

Afterwards

The episode notes that 104 bodies were recovered from the seabed in 2011, and it includes interviews with family members. It ends with the changes to training: at the time, pilots of this type were not trained to fly it by hand at high altitude, because the autopilot was expected to do that.

Note: the episode gives 3 April 2011 for the discovery of the wreckage and 12 kilometres from the last position. The BEA report gives 2 April 2011 and about 6.5 nautical miles (12 km).