THE 2009 Air France plane crash that killed all 228 people on board — including three Irishwomen — was caused by a mixture of human and technical mistakes.
Information leaked from the French civil aviation safety bureau’s (BEA) examination of the plane’s recently recovered black boxes has claimed the crash was linked to mechanical issues and the fact the pilot was not in the cockpit when the crisis occurred.
German magazine Der Spiegel has reported that initial findings from the investigation point to the mixture of problems.
Sources working on the investigation have confirmed that when Air France flight 447 left Rio de Janeiro for Paris on June 1, 2009, no concerns had been raised.
The first safety concern over weather conditions was raised on the plane’s monitors while over the Sargasso Sea area between South America and Africa.
On recordings from two black boxes recovered from the floor of the Atlantic last month, pilot Marc Dubois is heard calling out to his two co-pilots as he was not in the cockpit.
Within four minutes, the plane had plunged at high speed into the ocean, killing everyone on board — including Irish doctors Aisling Butler, 26, Jane Deasy, 27, and Eithne Walls, 29.
Sources said that the abruptness of the emergency was almost certainly linked to weather conditions.
This is because, due to changing climates and weather streams caused by an “inter-tropical convergence zone” near the Sargasso Sea, significant amounts of water particles can be dragged into the sky, which then freeze at high altitude.
If a plane is caught up in such an event, its speed readers ice over, leading to a crisis known in aviation circles as a “deep stall”.
If the crew of the airplane do not recover control immediately, the airplane will descend rapidly, without the ability to recover.
It is understood that when the Air France flight encountered this event, it attempted to pull up to higher altitude.
The BEA does not consider this to be the best course of action, a source told Der Spiegel. Investigators are examining whether the move was caused by a mechanical fault or by pilot error.
While it has previously been suggested that the crew may have inadvertently flown directly into the path of a storm, initial findings also appear to reject this view.
The findings state that the pilot and co-pilots seem to have sought the “safest route” and did not report increasingly severe turbulence before the crash.
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