Faulty warning systems and pilot error are to blame for the 2009 crash of Air France Flight 447 that killed all 228 people aboard, a report released by French air accident investigators says.
The final report from the BEA, France's equivalent of the U.S. NTSB, largely confirmed results of a preliminary investigation released last year, but it offered more details and recommendations.
Investigators cited "human and technical factors" for the June 1, 2009 crash in the Atlantic Ocean en route from Rio de Janeiro to Paris following a nearly two-year search for the plane's flight data recorders that finally located them in deep water in May of last year.
The Airbus A330's speed sensors, known as pitot tubes, may have frozen over, giving false readings, the investigators said. After the crash, Air France conducted a fleet-wide replacement of the suspect sensors.
According to the report, while Flight 447's pilot was on break, one of the copilots misread the plane's speed because of the faulty sensors and nosed up instead of down, as he should have. The plane was unable to recover from the stall and crashed.
"The crew was in a state of almost total loss of control of the situation," BEA chief investigator Alain Bouillard said. The agency's director, Jean-Paul Troadec, said the accident resulted from an airplane "being taken out of its normal operating environment by a crew that had not understood the situation."
The report called for better pilot training and improvements to plane warning systems.
Air France, in a statement, acknowledged that "a sequence and combination of several factors – technical and human – that led to the loss of the aircraft in just over four minutes." But the airline went on to say that the BEA report "confirms that the crew was properly trained and qualified in accordance with regulations and that the aircraft systems were functioning in accordance with design and met the applicable certification criteria."
Air France said had anticipated most of the report's recommendations and had already begun to make changes to its crew training programs.
Airbus said it would "take all measures to contribute to this collective effort towards optimizing air safety."
But, as The Associated Press reports, family members of the victims were less than satisfied with the report.
Robert Soulas, who lost his daughter in the crash, said that manufacturers had "known for years" about problems with the plane's sensors but didn't replace them until after the crash.
He said the "inappropriate behavior of the pilots" was prompted by "indication errors." He also said pilots should have had better training.