Within four and a half minutes in the early hours of June 1, 2009, an Airbus A330-200 operating as Air France Flight 447 from Rio de Janeiro, Brazil, to Paris, departed from cruise flight at 35,000 ft and descended into the Atlantic Ocean, killing all 216 passengers and 12 crewmembers. Glimpses of what might have gone wrong emerged from several interim reports issued by the French Bureau d’Enquêtes et d’Analyses (BEA) during its long investigation of the accident. In July 2012, the bureau published a nearly 300-page final report providing a full picture of what likely happened during those critical moments.
According to the report, the trouble began when the A330’s pitot tubes were obstructed by ice crystals, causing the various air data sources to produce unreliable airspeed information. Reacting as designed, the electronic flight control system (EFCS) rejected the air data, disengaged the autopilot and autothrottle, and reverted to a lower control law that provides fewer prot…
