"Our experts reached the conclusion that an inappropriate response by the crew after a brief malfunction of the plane's speed sensors" caused the crash, a new report on the 2009 flight 447 from Rio de Janeiro to Paris says.
Commissioned by French judges Sylvia Zimmermann and Sabine Kheris, this analysis is part of an investigation which is looking into the responsibility of airline Air France and plane-maker Airbus.
A year ago another report pointed to human error, technical failures and inappropriate procedures as the probable causes of the crash.
The latest report, written by five analysts, confirms that the plane’s speed sensors malfunctioned as the engine was overflying the intertropical convergence zone, an area where the trade winds come together causing a great density of ice crystals.
The accident "could have been avoided if the crew had taken appropriate action ", it concludes, adding that "the distribution of tasks in the cockpit was not rigorously applied", especially during the critical moment.
Those conclusions will be presented in court on 2 July as the case is still ongoing.
The report is “full of contradictions”, according to Yassine Bouzrou, the lawyer representing the victims' families.
"The experts are happy to blame the pilots while avoiding the key issue of technical failure," he told the AFP news agency.
Air France complained that the report had been leaked and claimed that it brought few “new elements” to light.