LE BOURGET, France — French investigators’ final report on the 2009 crash of an Air France jet that killed 228 people portrays a cockpit rapidly consumed by confusion and unable to decode a welter of alarms to determine which flight readings could be trusted, with one pilot’s apparent reliance on a faulty display cementing the plane into its fatal stall.

The report, released Thursday by the Bureau of Investigation and Analysis, concluded that the errors were the outcome of a confluence of factors beyond the competence of any individual pilot. The investigators stood by earlier findings that the pilots had not been adequately trained to fly the aircraft manually in the event of equipment failure or a stall at high altitude.

There was a “profound loss of understanding” among all three pilots of Air France Flight 447, an Airbus A330 en route from Rio de Janeiro to Paris, about what was happening after ice crystals threw off the plane’s airspeed sensors and the autopilot disconnected, the report said. The pilots then struggled to control the plane manually amid a barrage of alarms, a situation further confused by the faulty instructions displayed by an automated navigational aid called the flight director.

“The crew never understood they were in a stall situation,” the report said, “and therefore never undertook any recovery maneuvers.”

The report offered an answer to a central puzzle: the consistent and aggressive “nose up” inputs by the pilot at the controls, which added to the loss of lift. Pilots are normally trained to point the nose of the aircraft down in a stall to regain speed.

The report said that the readings being gathered by the automated flight director would have resulted in repeated calls for the plane’s nose to be lifted.

One aviation expert was troubled that the pilots did not appear to have the skills to start from the basic observation that airspeed indicators were giving conflicting readings and anticipate which of their flight readings — like that of the flight director — would therefore be untrustworthy.

William R. Voss, president of the Flight Safety Foundation in Alexandria, Va., said: “We are seeing a situation where we have pilots that can’t understand what the airplane is doing unless a computer interprets it for them. This isn’t a problem that is unique to Airbus or unique to Air France. It’s a new training challenge that the whole industry has to face.”