The Air France plane that plunged into the Atlantic en route from Brazil to France in 2009 stalled in mid air, according to French investigators.
The black boxes that were brought up from the sea bed earlier this month suggested that the pilots operating the Airbus A330 were unable to determine how fast the plane was flying.
This echoes earlier findings which suggest that the jet’s speed sensors iced up resulting in faulty data.
However, France’s Bureau of Investigation and Analysis (BEA) still does not understand why the pilots responded to the stall by pulling the nose up instead of pushing it down.
They wrestled with the controls as the plane plummeted for three and half minutes before hitting the sea.
All 228 people on board Flight 447 from Rio de Janeiro to Paris were killed.
Since the accident Air France has replaced the speed sensors on its Airbus fleet with a newer model.