Crash Tests for Dummies

Safety Demo If you are a frequent flier you have no doubt ended up in an exit seat, either by default or preference. Perhaps you have assumed that opening exit doors must be (Photo-NASA) intuitive since flight attendants never talk about it too much. Or perhaps you're resigned to the idea that if the plane crashed you wouldn't be worrying about either exit doors or flotation devices.

The Air France crash in Toronto early this month precipitated new public concern about airplane evacuations. Investigations found that only one of the exit doors functioned. Others were blocked by fire, some were considered too dangerous to use, and two of the exit chutes failed to deploy. Although ALL passengers exited intact from one door, this was considered a remarkable feat.

Despite our worst fears, a scan of the National Transportation Safety Board data from all airline crashes and incidents shows that many passengers do survive airplane crashes. Furthermore, research shows that it's not just a random matter, unresolved, except speculation about which end of the airplane will break off in mid-air. Who survives, how, and why they do, turns out to be much more than luck of the draw.

Aircraft evacuation procedures have been studied extensively in the US and abroad, notably by the Civil Aviation Authority in UK using research teams at Cranfield University. The UK studies were started after a devastating crash in Manchester on August 22, 1985 when 55 people died aboard a burning aircraft as the result of a fuel spill during an attempted take-off. Most of the people who died were incapacitated by smoke and toxic gas but a subsequent analysis found that limited access to the exits, non-functioning exits, and competition among passengers significantly hampered evacuation.

The Cranfield group was contracted by the CAA to conduct research following this crash in order to provide data that could be used to guide aircraft safety regulation requirements. The research is on-going and the university has teams of scientists who study parameters like airline seat configuration and flight attendant training to determine the effects on evacuation results. Some of their interesting and apropos studies show how the behavior of passengers alters outcomes of an evacuation, and what happens when the crash atmosphere is simulated by offering incentives to the study subjects.

A KTVU report last Sunday evening (not available online) included footage of airplane exit evacuation studies that showed dramatic differences between two types of evacuation simulations. The report juxtaposed film footage from controlled exit evacuations conducted in the US by the airlines to pass FAA requirements, with evacuations conducted under more "realistic" conditions run by Cranfield University for the CAA.

The US airline evacuations look like nice orderly affairs. An official looking person stands poised on the outside of the test aircraft. On cue, he deftly sweeps aside the cloth prop that stood in for the "exit door" with a practiced flourish. Then bouncy, able-bodied, height-weight proportional study participants - "passengers" - neatly, politely and safely jump out of the aircraft. How safe looking - our fears are assuaged.

The UK study film footage is a different scene. Real doors apparently weigh 65 pounds and need to be wrestled off by a passenger on the inside of the airplane. (In real life situations sometimes passengers haven't been able to remove the doors, either because they don't know how or because the doors are too heavy.) Film footage from the inside of the plane shows the "passengers" scrambling over the tops of seats and each other to get out the exits. It's pure chaos, which doesn't film well because large humans climbing over the top of airline seats in a big, big hurry is an ugly and brutish affair. An outside camera focuses on the exit door where passengers compete to squash through the exit head-first. They get stuck, jammed together in the exit at their hips, unable to budge. Someone, a spotter perhaps, pulls futilely at an arm trying to unlodge the over-eager study volunteers.

In this more alarming simulation the researchers had offered eight dollars to those subjects in the drill who could get out of the aircraft first. It was one of a series of studies run since the Manchester study that vividly captures the type of behavior that that insues if incentives are altered to simulate panic. A study in 1996 published in the International Journal of Aviation Psychology by Muir et al (vol 6, no 1; 1996); found that although:

"blockages adjacent to the exits were more likely to occur when space was at a minimum...serious blockages occurred only when volunteers were competing with one another."

Due to the findings of the group over the years, UK has mandated wider exit rows on their planes. Despite all the research though, situations such as Air France's exit door failures still occur. Some accidents are inevitable. The KTVU report focusing on the aircraft configuration changes, indicated that some of safety the changes initiated by the UK as a result of their research have not been initiated the US.

Various sources offer exit tips for passengers and it turns out that there's quite a few rescue measures that your average airline passenger may not have considered. Some people offer that you should, "keep your cool", but in the next sentence say; "if the aisle is clogged, go over the seats". The FAA suggests that people should remember to wear heavy comfortable shoes and long sleeves flying (in case of fire). If crash landings on the ground seem dicey, evacuating after ditching into water is decidedly not for the faint of heart. In some water evacuation demonstrations they have used professional divers. There are some simple tricks to remember though. Exits in water landings are sometimes botched because people unbuckle their seat belts before the "in-rush of water" has stopped. Sometimes people panic and inflate their vests too soon and therefore can't get out of the exits - don't inflate the vest until after you've exited the plane. When exiting the plane in an emergency the FAA "tips" say never take anything with you . However "overseas travelers" they say, should "carry a survival kit...in your pockets". Once you have escaped to the outside of the aircraft the FAA suggests obliquely; "you should be sure to turn on your emergency locator transmitter". Perhaps that advice is for a flight attendant. If you land in the wilderness the FAA has an even more thorough and slightly more upbeat set of guidelines ('survival is 80% mental'...'don't be afraid of animals'...)

Bon Voyage!

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