Investigators said on Friday that Air France pilots made a series of errors on the Rio to Paris flight that crashed in 2009 killing 228 people, but the French flag-carrier insisted they were not to blame. French aviation authority BEA said pilots failed to react correctly when the Airbus jet lost altitude after its speed sensors froze up and failed, and lacked training to deal with the sensors\' failure. The pilots \"did not formally identify the loss of altitude\" despite an alarm ringing for nearly a minute, it said in a report. Air France immediately defended its pilots, however, saying this alarm had malfunctioned. \"Nothing at this stage can allow the crew\'s technical competence to be blamed\" for the crash, the airline said in a statement. It pointed to the failure of the speed sensors which it said contributed to \"a worsened and unstable piloting environment\". The BEA\'s report said the pilots failed to notice that the plane had lost altitude after its speed sensors, known as Pitots, malfunctioned during the overnight flight on June 1, 2009. They said the captain of the flight had gone out of the cockpit leaving two co-pilots in charge and had not given them a sufficiently \"clear\" briefing. Air France insisted: \"The crew on duty showed professionalism and stayed committed until the end to operating the flight. \"Air France salutes their courage and determination in these extreme conditions,\" it said, in a statement released at the same time as the BEA report on Friday. \"The altitude-loss alarm was activated and deactivated several times contradicting the real status of the aircraft, which contributed strongly to the crew\'s difficulty in analysing the situation,\" Air France said. Air France and Airbus are being investigated for alleged manslaughter in connection with the crash. The airline replaced the Pitots, manufactured by French company Thales, on its Airbus planes with a newer model after the crash. Friday\'s report was the third formal update from years of investigations into how flight AF447 crashed en route from Rio de Janeiro to Paris on June 1, 2009, killing all on board. The Inquiry and Analysis Bureau (BEA) took nearly two years to locate the wreck of the crash and its \"black box\" flight recorders and retrieve many of the victims\' bodies. Officials insisted earlier that the BEA\'s findings would not amount to an official attribution of blame for the disaster that has implicated pilots, the airline and plane and equipment makers. \"The BEA establishes the facts and makes recommendations based on those facts,\" Environment and Transport Minister Nathalie Kosciusko-Morizet said on RTL radio Friday. \"As to who is responsible, that is up to the courts.\" Victims\' families alleged that the involvement of big French corporations such as Airbus and Air France was influencing the affair. \"The economic stakes take precedence over the search for the truth,\" said Robert Soulas, leader of a victims\' relatives\' association. Rescue workers recovered 50 bodies in the days immediately after the crash and this year retrieved a further 104, which were returned to France last month. More than 70 could not be recovered.