Sources speaking ahead of an official release of information expected Friday suggest that content collected from the cockpit voice and data recorders of Air France Flight 447 is building a case for pilot error. The investigation has so far implicated pitot tubes, which may have fallen victim to icing at 35,000 feet. But The Wall Street Journal reported Wednesday that "people familiar with preliminary findings" say that while the pitots did cause sensor malfunctions, cockpit displays functioned normally. Problems with the Airbus A330's pitot tubes led to a series of automation failures, disconnects, warnings and alarms for Flight 447. The sources say that while the crew was working the series of problems, they appear to have missed other essential information.
According to the Journal, the crew "apparently had difficulty" keeping track of information that included power settings and the aircraft's flight path. Information gleaned from 447's cockpit voice and flight data recorders have not yet implicated any major system failure or malfunction of the aircraft itself that could have directly led to the crash. But a report published by investigators soon after the crash looked at 13 other airspeed sensor malfunctions on Airbus widebodies and found that sensor malfunctions had caused both the autopilot and autothrottles to disconnect. It found that crews took up to one minute to adjust engine thrust, manually, and nine of the episodes led to stall warnings. Airbus and Air France were aware of problem associated with the pitot tubes. The airline received replacement parts (new pitot tubes) six days before Flight 447 crashed. The crash aircraft had not yet been fitted with the new parts. Airbus and certain carriers (including Air France) have since emphasized instruction in high-altitude stall recovery. All 228 on board Air France Flight 447 died when the jet crashed into the Atlantic off the coast of Brazil on June 1, 2009. The impact crushed the bottom of the aircraft, suggesting it hit the water hard and at a relatively flat attitude.