WASHINGTON Pilots automation addiction has eroded their flying skills to the point that they sometimes dont know how to recover from stalls and other mid-flight problems, say pilots and safety officials. The weakened skills have contributed to hundreds of deaths in airline crashes in the last five years.
Some 51 loss of control accidents occurred in which planes stalled in flight or got into unusual positions from which pilots were unable to recover, making it the most common type of airline accident, according to the International Air Transport Association.
Were seeing a new breed of accident with these state-of-the art planes, said Rory Kay, an airline captain and co-chair of a Federal Aviation Administration advisory committee on pilot training. Were forgetting how to fly.
Opportunities for airline pilots to maintain their flying proficiency by manually flying planes are increasingly limited, the FAA committee recently warned. Airlines and regulators discourage or even prohibit pilots from turning off the autopilot and flying planes themselves, the committee said.
Fatal airline accidents have decreased dramatically in the U.S. over the past decade. However, The Associated Press interviewed pilots, industry officials and aviation safety experts who expressed concern about the implications of decreased opportunities for manual flight, and reviewed more than a dozen loss-of-control accidents around the world.
Safety experts say theyre seeing cases in which pilots who are suddenly confronted with a loss of computerized flight controls dont appear to know how to respond immediately, or they make errors sometimes fatally so.
A draft FAA study found pilots sometimes abdicate too much responsibility to automated systems.
Because these systems are so integrated in todays planes, one malfunctioning piece of equipment or a single bad computer instruction can suddenly cascade into a series of other failures, unnerving pilots who have been trained to rely on the equipment.
The study examined 46 accidents and major incidents, 734 voluntary reports by pilots and others as well as data from more than 9,000 flights in which a safety official rides in the cockpit to observe pilots in action. It found that in more than 60 percent of accidents, and 30 percent of major incidents, pilots had trouble manually flying the plane or made mistakes with automated flight controls.Pilot mistakes
A typical mistake was not recognizing that either the autopilot or the auto-throttle which controls power to the engines had disconnected. Others failed to take the proper steps to recover from a stall in flight or to monitor and maintain airspeed.
The airline industry is suffering from automation addiction, Kay said.
In the most recent fatal airline crash in the U.S., in 2009 near Buffalo, N.Y., the co-pilot of a regional airliner programmed incorrect information into the planes computers, causing it to slow to an unsafe speed.
That triggered a stall warning. The startled captain, who hadnt noticed the plane had slowed too much, responded by repeatedly pulling back on the control yoke, overriding two safety systems, when the correct procedure was to push forward.
An investigation later found there were no mechanical or structural problems that would have prevented the plane from flying if the captain had responded correctly. Instead, his actions caused an aerodynamic stall. The plane plummeted to earth, killing all 49 people aboard and one on the ground.
Two weeks after the New York accident, a Turkish Airlines Boeing 737 crashed into a field while trying to land in Amsterdam. Nine people were killed and 120 injured. An investigation found that one of the planes altimeters, which measures altitude, had fed incorrect information to the planes computers.
That, in turn, caused the auto-throttle to reduce speed to a dangerously slow level so that the plane lost lift and stalled. Dutch investigators described the flights three pilots automation surprise when they discovered the plane was about to stall. They hadnt been closely monitoring the airspeed.
The ability of pilots to respond to the unexpected loss or malfunction of automated aircraft systems is the big issue that we can no longer hide from in aviation, said Bill Voss, president of the Flight Safety Foundation in Alexandria, Va. Weve been very slow to recognize the consequence of it and deal with it.
The foundation, which is industry supported, promotes aviation safety around the world.
Airlines are also seeing smaller incidents in which pilots waste precious time repeatedly trying to restart the autopilot or fix other automated systems when what they should be doing is grasping the controls and flying the airplane, said Bob Coffman, another member of the FAA pilot training committee and an airline captain.
Opportunities to fly manually are especially limited at commuter airlines, where pilots may fly with the autopilot off for about 80 seconds out of a typical two-hour flight.
And experts say it is the less-experienced first officers, starting out at smaller carriers, who most need manual flying experience. Senior pilots, even if their manual flying skills are rusty, can at least draw on experiences flying older generations of less automated planes.
Airlines will have to rethink their operations fundamentally if theyre going to give pilots realistic opportunities to keep their flying skills honed, said Voss, the flight safety expert.