Pilot error is emerging as the most likely cause of the crash of the Air France Rio-Paris airbus which plunged into the South Atlantic in June 2009, killing all 228 people on board.
Preliminary investigation of black-box flight recorders, found three miles down in the ocean last month, suggest there was no major technical failure in the Airbus A330.
Separately, The Independent has learned that investigators believe the senior pilot may have been absent from the cockpit when the aircraft dived into the ocean four hours into its flight. His absence was not, in itself, unusual. There were two less-experienced pilots aboard.
The accident occurred when severe tropical storms lay directly in the aircraft's path. One of the mysteries of flight AF447 is why the pilots flew directly into the eye of the storm. Other flights over the South Atlantic that day steered around the bad weather.
A malfunction in speed recording equipment is still thought to have contributed to the aircraft's demise. But this alone is not thought capable of having caused the aircraft to crash.
Air France reacted angrily yesterday to suggestions the blame was moving away from Airbus. "At the present stage of the investigation, nothing points to either the responsibility, or the freedom from blame, of either of the principal actors," Air France said.
In an internal message to staff, the director general of Air France, Pierre-Henri Gourgeon, said "rumours" about pilot error were an attack on the "memory of our pilots". "I have total confidence in their professionalism," he added.
However, earlier in the day Airbus issued a message to all its customers stating that preliminary deciphering of the black boxes indicated there was no reason to make "any new recommendations" on the safe operation of other A330 aircraft. In other words, the black boxes had not shown any major design or maintenance fault which could explain the accident.
The French newspaper Le Figaro reported earlier that Airbus had been cleared by the first examinations of the flight recorders by the French accident investigation unit. It said the investigation was now concentrating on what the flight recorders might reveal about the performance of the pilots.
The Independent has learned that the captain, Marc Dubois, is believed to have been taking his rest period when the plane crashed. On a long flight, it is standard for the captain to fly the first leg and then take his rest.