French investigators say the pilots of an Air France plane that crashed into the Atlantic in 2009 lacked adequate training.
All 228 people on board the Airbus 330 from Brazil to France were killed.
The BEA says pilots failed to discuss repeated stall warnings and did not have the training to deal with the hazard.
An account of their last minutes, captured on flight recorders, concluded that the crew had failed to ''formally identify the loss of altitude'' despite an alarm ringing for nearly a minute.
The pilot then responded by pointing the nose upwards, instead of downwards - the standard response to a stall situation.
The report also said the pilots failed to alert passengers to the crisis as they struggled to regain control.
Air France has rejected the accusation.
Flight AF 447 went down on 1 June 2009 after running into an intense high-altitude thunderstorm, four hours into a flight from Rio de Janeiro in Brazil to Paris.
The flight recorders were recovered in April this year after a long search of 10,000 sq km of sea floor.