Asiana Flight 214's Crash Shows Airline Safety Progress
After a look at the battered wreckage of Asiana Airlines Flight 214 strewn along Runway 28L at San Francisco International Airport, most observers might assume the worst had happened. The tail section had been torn from the widebody Boeing 777 during an ill-fated landing. One of the huge engines was ripped from the aircraft’s wings. And a gaping gash atop the fuselage revealed a fire-gutted interior from the conflagration that engulfed the airliner soon after it came to rest next to the tarmac. Yet only two of the 307 passengers and crew on board the jumbo jet died in the July 6 crash. Thanks to near-empty fuel tanks, design enhancements that helped keep its aluminum body largely whole, and scores of safety modifications adopted since the 1980s, the crash landing of Flight 214 became primarily a story of survivability instead of disaster.
“This crash shows how the plane really did its job,” says Richard Aboulafia, vice president of analysis at the Teal Group consulting firm. “The fuselage stayed intact and kept almost everyone alive even after such a violent landing.” Adds Richard Healing, a former National Transportation Safety Board member who now runs Washington-based R Cubed Consulting: “This was a phenomenally survivable accident.”
Although investigators could take months to understand the wreck fully, the low loss of life suggests that advances such as more-resilient aluminum hulls and continuing efforts to forestall onboard fires are having an impact. “Aircraft are generally more crashworthy now than they were,” says Paul Hayes, director of air safety at aviation consulting firm Ascend.
Fatal plane crashes remain rare. According to Ascend, about 9.9 million air passengers were carried for every one that lost his or her life in a crash in 2012. That’s a 20 percent improvement from 2011. The passenger fatality rate for the last five years is one per 6.1 million; in the 1990s, it was one per 1.8 million. “We took a very safe industry and made it even safer,” says consultant Robert Mann. “The problem is when you get down to these vanishingly low accident rates, the space to improve decreases.”
Designing more crash-proof planes has meant studying previous tragedies, or what industry experts bluntly call tombstoning. “As far as seeing how crashworthy is an airplane, all the computer modeling isn’t as good as having an actual crash,” says Hans Weber, president of consultant Tecop International.
Such research led the Federal Aviation Administration in 1988 to mandate that newly developed aircraft have passenger seats that can withstand 16 times the force of gravity, up from the previous standard of nine times. “These new 16G seats stay firmly bolted into the floor system, whereas in the past the seats would break free and pancake into each other and cause fatalities,” says Kevin Hiatt, a former Delta Air Lines pilot who is chief executive officer of the Flight Safety Foundation.
Past accidents also prompted the FAA and European Aviation Safety Agency to require that manufacturers design their planes to allow for 90-second evacuations even if half the emergency exits are blocked. Airbus’s mammoth A380 double-decker widebody passed that test in 2006, when 873 occupants were removed in 80 seconds. (The only injury was a broken leg.) Modern aircraft also are required to have nonflammable material for seat cushions, carpet, walls, and other interior parts. Insulation blankets in aircraft walls are designed to slow the spread of flames. That protection, plus the jet’s skin, can provide at least four minutes for evacuation before a fuel-fed post-crash fire can burn through the interior of the passenger cabin, according to Boeing.
“Thirty years ago there were survivable accidents but people died in the post-crash fire,” says Steve Wallace, former head of the FAA’s accident investigation office. “The cabin interior materials are vastly improved now, and rules were rewritten around getting precious more seconds to get everybody out of that airplane.”
In the Asiana crash, Bill Waldock, a professor who teaches crash investigation at Embry-Riddle Aeronautical University, says investigators and aircraft designers will review the way the 777’s tail, which is made of composites, broke off whereas the aluminum alloy fuselage (the central body of the plane that carries most of the passengers and crew) stayed intact. “They’ll be looking at the crashworthiness aspects of it,” Waldock says, “what helped so many people survive and where the weak spots were.”
Todd Curtis, a former safety analyst at Boeing who now runs AirSafe.com, a safety and crash data firm, has seen such lessons taken to heart. The circumstances of the hydraulic failure that caused the 1989 crash of a DC-10 in Sioux City, Iowa, killing 111, were once thought to be nearly impossible. Events proved otherwise, and engineers then fashioned ways to allow pilots to maintain some control if a mechanical failure robbed them of the ability to steer, he says. “This Asiana crash will be studied, too,” Curtis says. “It will inform future design in ways we can’t even guess yet.”
Still, more study of structural stress loads or fire retardant materials won’t have much effect on the largest causes of aviation accidents: the human element. According to the FAA, three of four aircraft accidents result from some form of “improper human performance” rather than mechanical issues. That’s one reason the San Francisco accident, like an Air France crash that killed 228 people in 2009, is again sparking debate over whether basic flying skills are becoming a lost art for pilots conditioned to helming planes so sophisticated they can land themselves. “The stick-and-rudder skills get lost sometimes,” says Mark Epperson, a former chief pilot for American Airlines in San Francisco.
Pilots’ ability to switch adroitly between full and limited automation, where the aviator’s flying skills supersede a jet’s technology, “should be of concern to the entire industry,” says David Greenberg, a consultant and former executive vice president of operations at Korean Air Lines.
An inactive glide-slope indicator on the San Francisco runway, which forced the Asiana crew to disengage the jet’s autopilot and fly using visual clues, “should not have led to this result, and I can’t say it was the cause, but there’s a good chance it was a factor,” says Greenberg.