Scene from the plane wreck
Technical failure and human error led to the loss of an Air France flight over the Atlantic in June 2009 and the deaths of 228 people, according to the final report into the crash.
The report by France's aviation authority, the BEA, blames the Airbus A330's ergonomics as well as inappropriate action by the pilots.
The jet disappeared in a storm while en route to Paris from Rio de Janeiro.
It took nearly two years for the flight recorders to be found.
The BEA said that the disaster began with the malfunctioning of speed sensors known as Pitots during a period of turbulence.
The captain was taking a rest break and the co-pilots were in control at the time.
The captain returned to the flight deck but was unable to reverse the catastrophic course of events.
One of the mistakes of the crew was to point the nose of the aircraft upwards after it stalled, instead of down.
"The crew was in a state of almost total loss of control of the situation," BEA chief investigator Alain Bouillard told journalists on Thursday at the release of the final report.
They never understood that the plane was in a stall as it descended at 11,000ft (3,352m) per minute, he added.
And BEA director Jean-Paul Troadec said: "This accident results from an aeroplane being taken out of its normal operating environment by a crew that had not understood the situation."
The report makes 25 new safety recommendations on top of the 25 called for in a preliminary report last year.
Investigator-in-charge Alain Bouillard: ''The crew had almost lost complete control of the situation''
These include better pilot training and improvements to plane warning systems.
In response, Airbus said in a statement that it would "take all measures to contribute to this collective effort towards optimising air safety".
But families of some crash victims criticised the report as too soft on the aerospace industry, Reuters news agency reported.
Investigators have found fault with both Airbus and Air France, sparking a row between the two firms over their accountability for the crash.
Both companies are under investigation by French magistrates for alleged manslaughter.
A separate judicial report will be released next week.
This is also expected to echo Thursday's report by the BEA, the French news agency AFP says.
Since the crash, Air France has replaced the speed sensors on its fleet of Airbus jets - made by the French firm Thales - with a newer model.
The wreckage of the plane was discovered after a long search of 10,000 sq km (3,860 sq miles) of sea floor.
After 23 months of searching, robot submarines finally found the flight "black box" recorders last year.