By ANDY PASZTOR And DANIEL MICHAELS
The airline industry is expected to implement major changes in its training procedures—particularly those intended to help pilots quickly react and regain control in the event of high-altitude flight upsets—following a report last week that shed light on the 2009 stall and crash of an Air France jet.
While cruising at 35,000 feet and nearly four hours into what seemed a routine overnight flight to Paris from Rio de Janeiro, Air France pilots got a stall warning and responded by yanking the nose of the plane up, instead of pointing it down to gain essential speed, according to information released Friday by French accident investigators.
The June 2009 crash took the lives of all 228 on board.
Apparently confused by repeated stall warnings and reacting to wildly fluctuating airspeed indications, pilots of Flight 447 continued to pull back sharply on the controls for almost a minute—even as the Airbus A330 plummeted toward the water, according to the information released Friday.
The report raised questions about how seasoned pilots for a top airline, flying one of the industry's most advanced jets, violated such a fundamental rule of airmanship.
The aviation industry already implemented major changes in pilot training months before Friday's release, but the report is bound to set the stage for further training revisions, according to international safety experts.
Led by aircraft manufacturers Boeing Co. and Airbus—and supported by airlines and regulators on both sides of the Atlantic—new stall-recovery training programs have been developed to reiterate the importance of reducing the upward angle of the nose of the aircraft as pilots add power to regain speed and control.
While French investigators are months away from releasing their final conclusions and safety recommendations from the Air France probe, critics of traditional stall-recovery training are pushing for further changes to help pilots feel more comfortable manually controlling planes in various emergencies.
Claude Lelaie, a top Airbus safety official, told an international safety conference in Istanbul in March that the manufacturer for months had been advocating revised stall-recovery procedures emphasizing "more pitch down control" to push down the nose of the aircraft and reduce its "angle of attack," or the angle between the airflow and the longitudinal axis of the plane.
Specifically, the Airbus official told the conference that after the Air France crash, pilots for the first time were trained to recover from stalls at high altitudes, without the benefit of certain computer aids. "Pilots were afraid of that" technique in the past, he said, because standard simulator training assumed certain automated protections would remain in place.
The introduction of automation has made flying dramatically safer over the years. In the U.S., for instance, fatal accident rates are at record lows. But if pilots are taught to abdicate too much responsibility to automated systems, essential piloting skills can dull and aviators become too reliant on computers in emergencies.
That's particularly troublesome if onboard flight-control computers malfunction, disconnect or, as in the case of Flight 447, give conflicting information and warnings to pilots. "Pilots are starting to serve the automation, not the automation serving the pilots," said Bill Voss, president of the Flight Safety Foundation of Alexandria, Va., an independent advocacy group championing enhanced training. "It's almost like we have to train the pilots to know how to triage these situations."
The long-awaited factual report, though it doesn't explicitly say the pilots acted improperly, provides important new details about their actions during a dangerous loss of forward momentum that lasted more than three and a half minutes. Investigators already concluded that except for malfunctioning airspeed probes, there were no other mechanical, electrical or system errors.
The report paints a somewhat unflattering picture of a seemingly confused cockpit, with the crew making extreme inputs to their flight controls and the engines spooling up to full power and later the thrust levers being pulled back to idle. At one point, according to the report, both pilots sitting in front of the controls tried to simultaneously put in commands.
The preliminary findings offer "a strong piece of evidence that as an industry, we need to improve upset recovery training," said John Cox, a former airline pilot and accident investigator who now runs Safety Operating Systems LLC, a consulting firm based in Washington, D.C.
The senior captain on the flight, Marc Dubois, who was on a routine rest break in the cabin when the trouble started, rushed back to the cockpit and was present and observing the other pilots' actions during a large portion of the descent.
Air France praised the three pilots, who "demonstrated a totally professional attitude and were committed to carrying out their task to the very end," the airline said in a statement.
The carrier, a unit of Air France-KLM SA, noted that "the initial problem was the failure of the speed probes which led to the disconnection of the autopilot and the loss of the associated piloting protection systems."
The largest trade union representing Air France pilots, SNPL, said Friday the report "describes only part of the sequence of events experienced by the crew" and it awaits the full report.
Throughout the sudden descent, according to the report, "inputs made by the [pilot flying] were mainly nose-up," which reduced the plane's lift. Pilots are taught from their earliest training that if an airplane begins to stall and its wings have lost the lift to remain airborne, they should immediately push the nose down to regain speed, lift and maneuverability.
The report could provide ammunition for the lawsuits against Air France, though plaintiffs also are likely to pursue Airbus for how it handled airspeed-indication issues over the years.
The problems with the speed probes on the Air France plane, and others like it, were well known. They had a history of icing up and giving faulty readings. The probe's maker,Thales SA of France, declined to comment. Airbus and regulators had established procedures to handle such situations with the probes, which are called pitot tubes. These procedures focused on maintaining sufficient thrust and avoiding extreme maneuvers.
Airbus, a unit of European Aeronautic Defence & Space Co., said in a statement it is committed to continuing to provide support to the investigation "with the objective of identifying all potential lessons to be learnt."
About three hours and 40 minutes into the flight, when the airspeed-indication issue first cropped up and the pilots received their initial stall warning at around 35,000 feet, the report shows the crew maintained control and temporarily managed to stabilize the plane at an altitude above 37,000 feet. That took just under a minute.
But then with their jet basically flying level despite airspeed-sensors that continued to display unreliable readings, the pilots started to veer away from typical procedures, the data released Friday reveal. French investigators didn't comment on reasons for the crew's behavior.
Upon receiving a second stall warning, the crew increased engine thrust substantially—part of standard practice to cope with such a situation. But for the next 50 seconds, the pilot at the controls did something that safety experts consider anathema: He continued to pull the jet's nose up, despite the threat of worsening the stall.
About two minutes after the first problems—and with the captain back in the cockpit—the jet was falling at a rate of 10,000 feet a minute, comparable to dropping 15 stories a second in an elevator. Yet the plane's nose remained pointed sharply upward as the wings rocked side to side and its forward speed hovered around 100 miles an hour, too slow for a jetliner to fly.
"I don't have any more indications," one of the pilots said, perhaps referring to airspeed but possibly something else. "We have no valid indications." The report doesn't elaborate.
At that juncture, according to the report, both thrust levers were pulled back to idle. The report also said that both engines were operating and responding normally to pilot commands.
The report goes on to describe how roughly a minute later, with the plane already dropping to around 10,000 feet altitude, there were "simultaneous inputs by both pilots on the sidesticks" that control the aircraft, with one of the pilots trying to clear up the confusion by telling the other "go ahead, you have the controls." Pilots are trained to avoid such simultaneous commands.
The plane's data recorders stopped four minutes and 27 seconds after the autopilot kicked off, with the plane still dropping at roughly 10,000 feet a minute, tail down and slightly rolled to the left.
Air France has had a history of safety issues over recent years. After the crash of an Air France Airbus A340 on landing in Toronto in 2005 that resulted in no fatalities but destroyed the plane, the airline ordered a thorough study of its approach to safety. The airline later said most of the report's recommendations had been implemented.
After the 2009 crash, the airline commissioned another study of its practices by a panel of leading international safety experts. That report, which was delivered to the airline in January, found a lack of "strong safety leadership at all levels of management" that resulted in lax cockpit discipline and ineffective pilot training.
Air France said it was studying and implementing the report's recommendations.