Investigators probing a 2009 mid-Atlantic Air France plane crash that killed 228 people have blamed a combination of pilot error, inadequate training and technical problems.
A final report into the Rio-Paris Airbus A330 crash more than three years ago has called for improved pilot training and cockpit design among 25 recommendations to prevent a repeat of the disaster.
Pilots' trade unions and Air France have been at loggerheads with planemaker Airbus over who or what was to blame for the airline's worst loss.
France's BEA investigation authority confirmed earlier findings that the crew had mishandled its response to the loss of speed readings from faulty sensors that became iced up in turbulent conditions over the south Atlantic on June 1, 2009.
The doomed aircraft plunged for four minutes in darkness in an aerodynamic stall as its wings gasped for air while pilots failed to react to repeated stall alarms, according to flight recorders recovered two years after the crash.
BEA director Jean-Paul Troadec said: "This accident results from an airplane being taken out of its normal operating environment by a crew that had not understood the situation."
The report also found that the A330's speed sensors, known as pitot tubes and designed by France's Thales, were only upgraded after the disaster, even though there had been previous incidents with the equipment.
It urged Airbus to review the aircraft's stall warning system following criticism of the alarm's erratic behaviour when the plane was deep into its 38,000-foot plunge.
And it called for an overhaul of the way France's aviation and airline industries are supervised.
Families of crash victims immediately criticised the report as too soft on the aerospace industry, ensuring that a row over responsibility for the accident will linger as Air France and Airbus both face a French manslaughter investigation.
"It seems that the pilots were lured into error by the problems with the pitot tubes," said Robert Soulas, head of an association of families of the victims on board Flight 447.