Design of Asiana’s 777 Allowed Passengers Speedy Escape
From mostly empty fuel tanks to a tail-first strike slowing the plane, the crash of Asiana Airlines Inc. (020560)’s Flight 214 became a story of survivability instead of disaster.
The odds of living through the accident increased because of passengers belted in before landing, new seats able to withstand greater impact and the braking effect from hitting the ground short of the San Francisco airport runway, said Richard Healing, a former National Transportation Safety Board member.
“The airplane only went hundreds of feet after the tail hit, which tells you that a lot of the energy was absorbed,” said Healing, who now runs Washington-based R Cubed Consulting LLC. “It was at the end of the flight so the fuel tanks weren’t heavy. It was slowing. People had on their seatbelts. Everyone evacuated within minutes. This was a phenomenally survivable accident.”
Only two of the 307 people on board the wide-body Boeing Co. (BA) 777 died in the July 6 crash. Once the jet skidded to a stop on the airport grass, the crew hustled travelers down emergency slides ahead of a blaze that eventually gutted the hull and left officials marveling that the toll wasn’t worse.
Flight 214 was arriving from Seoul after a flight of more than 10 hours across the Northern Pacific for what should have been a routine touchdown on Runway 28 Left. While some on board said afterward that a steep descent stirred fear of a crash, there were no warnings to prepare for an accident.
“Split-second” reactions in evacuating the plane were critical, said Robert Mann, a former airline executive who now runs consultant R.W. Mann & Co. in Port Washington, New York. “It just happened. It’s a miraculous outcome.”
The way the Asiana jet came to a halt quickly after impact, in the middle of an airfield with no other obstacles in its path, also gave those on board time to escape, said George Hamlin, a former executive at planemaker Airbus SAS.
“Although the tail broke off and there was a fire, the passenger compartment was preserved pretty much intact following the impact, and it came to rest pretty quickly on the ground instead of in San Francisco Bay,” said Hamlin, president of Hamilton Transportation Consulting in Fairfax, Virginia.
Lee Kang Kuk, a co-pilot on the Asiana jet was in the process of transitioning from flying Boeing 737 model to the 777 model, South Korean Transport Ministry official Choi Jung Ho told reporters in Seoul. The Ministry is still investigating whether Lee Kang Kuk or the other pilot Lee Jung Min had control of the plane during landing because control is “easily transferrable” between pilots depending on flight situation, according to Transport Ministry official Choi Seung Yeon.
Shares of Asiana, South Korea’s second-largest airline, fell 5.8 percent to close at 4,825 won in Seoul.
Crashes that prove less dire than they might appear on video aren’t unknown in the industry. The 2009 water landing in New York that was dubbed the “Miracle on the Hudson” may be the best-known example.
Designing more crash-proof planes has meant studying the grim lessons of previous tragedies.
Those efforts produced standards such as a requirement that airliners can be evacuated in 90 seconds even if half of the emergency exits are blocked.
“Thirty years ago there were survivable accidents but people died in the post-crash fire,” said Steve Wallace, former head of the Federal Aviation Administration’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.”
Boeing’s 777 is the planemaker’s biggest twin-engine model, and it’s among the newest and most technologically advanced commercial aircraft in the global airline fleet.
Introduced in 1995, the jet features seats that can withstand 16 times the force of gravity, compared with the previous standard of 9 times, according to Boeing. All new aircraft designed and built after 1998 have the 16G seats, according to the Chicago-based planemaker. The jet that crashed in San Francisco was delivered in March 2006, Boeing said.
Modern aircraft also are required to have non-flammable material for seat cushions, carpet, walls and other interior parts. Insulation blankets in aircraft walls are designed to slow the spread of flames, and along with the jet’s skin can provide at least four minutes for evacuation before a fuel-fed post-crash fire can burn through, according to documents on Boeing’s website.
“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 or more severe injuries,” said Kevin Hiatt, chief executive officer of the Flight Safety Foundation in Alexandria, Virginia, and a former Delta Air Lines Inc. (DAL) pilot who flew 777s among other jets.
The high survival rate on the Asiana plane is reminiscent of a 2005 crash in which an Airbus A340 flown by Air France carrying 309 people skidded off a Toronto runway and burst into flames, said Wallace, the former FAA official. Everyone on board that four-engine wide-body jet escaped.
“In Toronto, 309 people got off that airplane with no life-threatening injuries, and that plane was burnt out worse than this one,” Wallace said.
Chesley B. “Sully” Sullenberger III, the US Airways Group Inc. (LCC) pilot who safely landed an Airbus A320 jet on the Hudson River in 2009, said investigators in the Asiana probe also would focus on understanding the crew interactions.
“We need to find out what the human factors were that, in a timely response, could have prevented this,” Sullenberger, who is now a safety advocate and speaker, said today in an interview on Bloomberg Television.
Hiatt of the Flight Safety Foundation predicted that the Asiana accident “will be a landmark, one we’ll point to for survivability” research and design improvements.
Todd Curtis, a former safety analyst at Boeing who worked on the 777 and now runs AirSafe.com, a safety advocacy and crash data firm, has seen those lessons taken to heart.
The circumstances of the hydraulic failure that caused the 1989 crash of a DC-10 in Sioux City, Iowa, were once thought to be impossible. Events proved otherwise, and engineers then fashioned ways to allow pilots to keep some control if a mechanical failure robbed them of the ability to steer, he said.
“This Asiana crash will be studied, too,” Curtis said. “It will inform future design in ways we can’t even guess yet.”
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