September 18, 2011


Cockpit crisis: In five years, over 50 commercial airplanes crashed in loss-of-control accidents. What's going on? (Chris Sorensen, August 24, 2011, Macleans)

Statistically speaking, modern avionics have made flying safer than ever. But the crash of Flight 1951 is just one of several recent, high-profile reminders that minor problems can quickly snowball into horrific disasters when pilots don't understand the increasingly complex systems in the cockpit, or don't use them properly. The point was hammered home later that year when Air France Flight 447 stalled at nearly 38,000 feet and ended up crashing into the Atlantic, killing all 228 on board. Investigators recently released transcripts from the Airbus A330's cockpit voice recorder. It reveals a flight crew gripped by confusion as they tried to diagnose and respond to what should have been a manageable mid-air emergency, but instead resulted in a terrifying 3½-minute plunge in total darkness. "I don't have control of the airplane anymore," the co-pilot at the controls said at one point. "Now I don't have control of the airplane at all."

Despite being responsible for the lion's share of passenger deaths over the past decade, it's only recently that the industry has begun to treat so-called "loss-of-control" accidents as a serious issue. Sunjoo Advani, an expert in flight simulation and the president of a Netherlands-based simulation and engineering consulting firm, says he received puzzled looks when, back in 2007, he suggested that Britain's Royal Aeronautical Society (RAeS), an influential safety group, hold a conference on the issue. Not anymore. Advani has spent the past two years coordinating the International Committee for Aviation Training in Extended Envelopes, or ICATEE, a panel of experts asked by the RAeS to look into stalls and other loss-of-control accidents and find ways to prevent them. "Many of these accidents are recoverable," he says. "They simply shouldn't have happened. In many incidents, the airplane has gone into a stall and every automated safety procedure kicked in, but the pilots failed to recognize the situation and failed to recover."

Why is it happening? Some argue that the sheer complexity of modern flight systems, though designed to improve safety and reliability, can overwhelm even the most experienced pilots when something actually goes wrong. Others say an increasing reliance on automated flight may be dulling pilots' sense of flying a plane, leaving them ill-equipped to take over in an emergency. Still others question whether pilot-training programs have lagged behind the industry's rapid technological advances.

It's a vexing problem for airlines, and a worrisome one for their customers. Unlike mechanical failures that can be traced to flawed design or poor maintenance, there is no easy fix when experienced and highly trained pilots make seemingly inexplicable decisions that end with a US$250-million airplane literally falling out of the sky. "The best you can do is teach pilots to understand automation and not to fight it," Advani says, noting that the focus in recent years has, perhaps myopically, been on simplifying and speeding up training regimes, secure in the knowledge that planes have never been smarter or safer. "We've worked ourselves into a little bit of a corner here. Now we have to work ourselves back out."

In the past five years alone, there have been more than 50 stalls and other loss-of-control accidents involving commercial airlines, nearly all of them fatal, according to the International Air Transport Association. Unlike a car or truck, a plane stalls when its wings stop producing lift--effectively transforming it from an elegant flying machine into a giant brick. That happens when the angle of attack (the angle of the wing relative to the direction the plane is flying) becomes too extreme. In most cases, stalls occur because a pilot is flying too slowly to maintain altitude, although they can theoretically occur at any speed. To recover, pilots are taught to apply thrust and to lower the nose of the aircraft. A 2010 study by Boeing found that 20 different loss-of-control accidents were responsible for nearly 1,850 deaths between 2000 and 2009, nearly double the number of fatalities of the next biggest category, "controlled flight into terrain," which is basically the flying of a plane into the side of a mountain. That makes loss of control, including stalls, both the single most common cause of fatal airline crashes, and by far the most deadly.

But stalls needn't be fatal events. Pilots are taught how to recover from them in basic flight school, and many modern planes are equipped with systems designed to prevent them from occurring in the first place. In modern Airbus-built planes, for example, an electronic fly-by-wire control system means a pilot who hauls back on the side-stick controller, a joystick-like device that has replaced a traditional control yoke in Airbus cockpits, will not be permitted by the computer to put the plane and its passengers in a dangerous situation.

And yet loss-of-control crashes continue to bedevil the industry. And several recent accident investigations reveal a disturbing trend: highly trained pilots who, when faced with a stall, not only fail to correctly diagnose the problem, but take actions that make their predicaments far worse.

Man wasn't meant to fly.

Posted by at September 18, 2011 11:45 PM

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