AF 447 Final Report Highlights Pilots' Training
The co-pilots who were in the cockpit when Air France Flight 447 ran into trouble and then crashed June 1, 2009, were startled and never grasped that the plane was stalling, France's aviation accident investigative agency concluded.
The final report from France's Bureau d'Enquetes et d'Analyses pour la securite de l'aviation civile (BEA), its aviation accident investigative agency, basically confirms what already is known about the crash, which killed all 228 people aboard the plane. It crashed after flying into a high-altitude thunderstorm off the northeastern coast of Brazil, and the co-pilots had no training for flying the plane manually at high altitudes, BEA said in its July 2011 third report on the case.
The final report issued July 5, 2012, concludes they were startled when the autopilot disengaged and no airspeed data were displayed. The likely cause of the disengagement was ice crystals blocking three Pitot probes; this phenomenon "was known but misunderstood by the aviation community at the time of the accident," BEA's final report states. It concludes the co-pilots had difficulty handling the aircraft at high altitudes in turbulence, and as a result the one controlling the plane gave erroneous inputs that worsened the situation. "The crew, progressively becoming de-structured, likely never understood that it was faced with a 'simple' loss of three sources of airspeed information," the report states on page 199.
The assumption is that pilots will correctly diagnose an in-flight problem and then find and employ the necessary procedures to solve it. But that did not happen here, which the report says "shows the limits of the current safety model.... A crew can be faced with an unexpected situation leading to a momentary but profound loss of comprehension. If, in this case, the supposed capacity for initial mastery and then diagnosis is lost, the initial inability to master the flight path also made it impossible to understand the situation and to access the planned solution."
The report's new recommendations include that the European Aviation Safety Agency ensure that pilots receive initial and recurrent training so they know how to handle aircraft at the limits of the flight envelope, understand flight mechanics at high altitude, and develop the capacity to manage crew resources when faced with unexpected situations.
Air France issued a statement thanking the BEA experts and paying tribute to the memory of the passengers and crew members who died. "In its analysis and conclusions, the BEA underlines a sequence and combination of several factors –- technical and human -– that led to the loss of the aircraft in just over four minutes," the statement says. "It confirms that the crew was properly trained and qualified in accordance with regulations and that the aircraft systems were functioning in accordance with design and met the applicable certification criteria. The BEA report describes a crew who acted in line with the information provided by the cockpit instruments and systems, and the aircraft behaviour as it was perceptible in the cockpit: instrument indications, triggering and stoppage of the alarms, aerodynamic noise, aircraft vibrations, etc. The reading of the various data did not enable them to apply the appropriate action. In this deteriorated aircraft cockpit environment, the crew, with the skills of one flight captain and two first officers, were committed to carrying out their task of piloting the aircraft to the very end. Air France wishes to pay tribute to their courage and determination in these extreme conditions."
The airline said it is currently involved in an ongoing process of improving flight safety procedures.
The report is of equal interest and importance to Airbus, which manufactured the plane and has watched closely to see what the investigators concluded about the stall warnings, displays, and systems used to fly it and to warn pilots of problems. In a statement posted on parent company EADS' investor relations website, Airbus said it welcomed the final report and has been involved from the start in investigating the crash. "The parties have spared no effort to seek a full understanding of this tragic event, driven by the collective goal of continuous improvement in aviation safety and their dedication to applying lessons learnt across the aviation industry for the benefit of the flying public and in respect of the victims and their families," the statement says. "The publication of the BEA's final report now provides the opportunity to further work on the lessons learned from this tragedy and measures to be applied to avoid the recurrence of such an accident. Without waiting for this final report, Airbus has already started working at industry level to further reinforce the robustness of pitot probes requirements and actively supports related activities. Airbus will examine the report now in full detail and seize upon every measure possible to contribute to the collective efforts toward further improving aviation safety. Airbus expresses its sympathy to all those who have lost family, friends or loved ones in this tragic accident."