Paris ( CNN ) -- Questions were raised Friday over the training of the pilots on the doomed Air France Flight 447 , after analysis of the plane 's voice and data recorders by a French investigation body . The recorders from the plane , which plunged into the Atlantic Ocean in June 2009 on its way from Brazil to France with the loss of 228 passengers and crew , were recovered in May , after almost two years on the sea bed . The data they provided has shed new light on the final minutes of the flight , France 's Bureau of Investigation and Analysis , the BEA , said as it issued its third report . The crisis arose after a problem involving blocked pitot tubes -- devices that measure a plane 's air speed -- which led to the disconnection of the autopilot , it said . The recorders revealed the pilots had failed to discuss repeated stall warnings and `` had received no high altitude training '' to deal with the situation , the BEA said . The pilots got conflicting air speed readings in the minutes leading up to the crash and , after the stall , responded by pointing the nose upward , rather than downward , to recover . They failed to regain control of the aircraft and no announcement was made to the passengers before it plummeted from the sky . The descent from 38,000 feet took 3 minutes and 30 seconds . Air France defended the pilots ' performance , saying there was `` no reason to question the crew 's technical skills '' in the face of `` multiple improbable factors . '' But an aviation expert questioned why the pilots did not correct the stall . `` Dealing with a stall situation is a fundamental part of being a pilot -- if you take private flying lessons , it is one of the things they teach you within the first few hours , '' said David Kaminiski-Morrow , an editor at Flight Global . `` Nobody seems to understand yet why they could n't get out of the stall , why the pilots were unable to apply what -- in hindsight -- seems to be a fairly straightforward procedure , '' he said . The BEA issued 10 new safety recommendations , including ensuring extra training for pilots on manual handling of a high-altitude stall , such as that experienced by AF 447 , and asking regulatory authorities to require airlines to equip planes with an image recorder to show what is displayed on the pilots ' whole instrument panel . The BEA also recommends that the triggering of location transmitters and a video recorder should be mandatory when an emergency is detected on board an aircraft . CNN 's aviation correspondent Richard Quest said the report `` shows that the original incident -- the blocked pitot tubes and failed speed sensor -- was serious but not catastrophic . '' `` It should have been relatively straightforward to deal with for an experienced flight crew . However , it was the response of the pilots which ultimately doomed the aircraft , '' he said . `` By focusing the attention on the way the cockpit crew handled the emergency , the BEA is recommending further training for pilots in dealing with high-altitude crises . `` Sources in the industry tell me that this incident , among others , is leading to a rethink and renewed emphasis on piloting skills . '' Kaminiski-Morrow said modern-day planes are capable of flying themselves most of the time , which means pilots have to be capable computer managers . `` The danger of this is that when things start going wrong , is the pilot still in the loop ? '' Kaminiski-Morrow said . `` The computer might recognize what 's wrong , but if the pilot does n't , how will he get out of it ? French Transport Minister Nathalie Kosciusko-Morizet told French radio network RTL that the BEA was responsible for establishing `` the facts '' and that it would be the courts ' role to assign any blame . Air France and Airbus are being investigated for alleged involuntary manslaughter over the crash . In its response to the report , Air France said the two co-pilots and the captain `` showed an unfailing professional attitude , remaining committed to their task to the very end . Air France pays tribute to the courage and determination they showed in such extreme conditions . '' It went on : `` From the flight recorder data , it has been established that the combination of multiple improbable factors led to the disaster in less than four minutes : the icing of the pitot probes was the initial event that led to the disconnection of the autopilot , the loss of associated piloting control protections and considerable roll movements . `` After the manoeuvres carried out by the crew in deteriorated and destabilizing piloting conditions , the aircraft stalled at high altitude , could not be recovered and struck the surface of the Atlantic Ocean at high speed . '' All 228 people aboard the Airbus A330 Flight 447 from Rio de Janeiro to Paris were killed in the crash . The bulk of the wreckage was found earlier this year after a search by robot submarines of an underwater mountain range . More than 150 bodies have been brought up from the scene of the crash , but more than 70 will never be recovered . CNN 's Jim Bitterman and Bryony Jones contributed to this report .
NEW : An aviation expert wonders why the pilots were not able to deal with the stall . The French report follows an analysis of data from the plane 's recorders . Air France says there is no reason to question the abilities of its crew . The recorders were retrieved from the Atlantic Ocean almost two years after the crash .