Plane Crashes In Pursuit of Safety
By: Patrick Kiger
Why would aviation researchers want a pilot to crash a Boeing 727 airliner in the Mexican desert on purpose? As you'll discover when you watch the "Plane Crash" episode of Curiosity on Monday, October 8 at 9PM, they did it for pretty much the same reason that their colleagues in the automotive industryslam vehicles into big metal contraptions with anthropomorphic dummies inside; They want to gather data that may enable them to figure out how to better enable people in real airline accidents to survive.
Plane crashes are pretty rare; From 2000 through 2009, U.S. commercial carriers averaged just 3 accidents per one million departures, and only 18 of the 195 accidents in that decade involved one or more fatalities and serious damage to the aircraft. We're conditioned from news reports about the loss of life in horrific plane crashes--for example, the 2009 crash outside Buffalo of Continental Airlines flight 3407, which killed all 49 people aboard--to assume that the odds are slim of surviving such a disaster. So it may come as a surprise to you that National Transportation Safety Board data shows that even in the most serious crashes, the ones in which an aircraft catches fire and the fuselage is damaged extensively or even completely destroyed, 55.6 percent of the occupants manage to emerge alive.
I've even met a man who was proof of that. A few years back, I did a magazine story about Willam Wang, the entrepreneur behind consumer electronics giant Vizio. In our interview, told me about his harrowing experience of surviving the November 2000 crash of a Boeing 747 airliner in Taiwan.
Basically, you have two minutes to live after the plane crashed. When the plane crashed, immediately the plane blew up, because of 60,000 gallons of jet fuel. But the moment…the oxygen was sucked away from the plane. There was no more air. So I don’t have the patience. I started running. I’m the only one running around while the plane is still moving. Fortunately, the door popped open. But it was a good two minutes without any air, just smoke and carbon dioxide. I was fading. Somehow the door popped open and blew me out the door. I was lucky enough to run away from the plane. I couldn't open the door., The bar was basically dead.I think what happened… I'm not sure until today. I think the door was dead. the entire plane, the inner part of the plane was like a tube, a vacuum tube. Because all the oxygen was sucked away by the explosion. But once the door popped open, the hot air tries to rush out, the cold air rushes in. The door blow open by itself. I tried to open the door for at least 20-30 seconds and I couldn’t open it. People who left the plane, the front part of the plane, lived. The people in the middle part got killed. They didn’t have a chance to run.
The question, then, is not whether passengers and crew can make it out alive, but how to improve the design and technology of airliners so that more of them live to tell the tale. Researchers in the U.S. government's Aircraft Crashworthiness Research Program, for example, have discovered that one of the key factors in survival is how well the cabin's interior furnishings hold up under stress. In many survivable accidents, occupants of aircraft have been injured by overhead bins, falling ceiling panels, and seat attachments that came loose. Another key factor is how well an occupant's seat absorbs the force of the crash landing, rather than transferring it to the person's spine. (Here's an analysis on the basic principles of crashworthiness, written by a retired U.S. military physician.)
While researchers can use computer modeling and laboratory simulations to approximate the conditions of a plane crash, there's nothing quite like having an actual crash to study--especially if they can equip the plane beforehand with sensors and other equipment that enable them to measure the effect of the event on both the aircraft and the occupants. But pre-planned crashes haven't been staged very often, because airliners are expensive and slamming one into the ground without hurting anybody is a tricky, exacting affair. The last time it was done was in 1984, when NASA's Dryden Flight Research Center and the Federal Aviation Adminstration crashed a Boeing 720 jet into steel structures set up in a dry lake bed in California, in order to deliberately rip open the fuel tanks in the wings. The idea was to test a then-promising new fuel additive designed to reduce the risk that an aircraft might burst into flames. Unfortunately, things didn't go quite as planned, and the crashed airliner ignited into a raging inferno tht took more than an hour to extinguish. Not surprisingly, the flame-retardant additive research effort was abandoned. Here's a government report on the experiment.
This time though, researchers had better luck, although the impact did rip the airliner in two, as this article from the UK's Daily Mail details.