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Airbus A380 Evacuation Tests.


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Wall Street Journal

 

Mar. 22, 2005 10:53 AM

 

The new Airbus A380 jetliner is so enormous that it will take almost one hour for its maximum load of 853 passengers to board. In an emergency, those same people must be able to escape within 90 seconds.

 

This summer, Airbus will see if it can meet that target. Inside a cavernous plant in Hamburg, Germany, volunteers playing the role of passengers and 20 crew members will board the two-deck airliner, sit down and buckle up. Organizers will toss blankets and baggage about to simulate the mess onboard after a survivable accident. Some participants representing parents with babies will receive lifelike dolls to cradle. Airbus technicians will retreat to observation points hidden inside dummy toilets and galleys, as regulators from Europe and the U.S. get in place to witness controlled chaos.

 

Airbus will then turn out the lights. Only half of the plane's 16 doors will open, replicating problems that complicate aviation emergencies. Slides will shoot out and inflate to the size of flatbed trailers. Flight attendants will yell in their best drill-sergeant voice: "Get out! Get out! Get out!"

 

Like everything else about the largest passenger plane ever built, the A380 evacuation test will happen on a grand scale. The engineers are pretty sure the mechanical equipment will work, but predicting how the humans will behave, particularly on such a large airplane, is what makes the planning so difficult. Because the plane's upper deck is two stories high, regulators are particularly interested to see what happens when the volunteers emerge at the edge of the high doorway and realize they must jump onto the steep and slick nylon slide. Will they balk and slow others' escape? Will they pile up in a human traffic jam at the bottom?

 

The A380, slated to make its first test flight by mid-April, must pass the cabin evacuation test before it can enter commercial service next year. If it fails, aviation authorities might force Airbus to limit its maximum passenger load. That could affect the A380's sales prospects for heavily traveled routes in Asia and the Middle East.

 

Most airlines buying the plane have announced plans to install around 550 seats, including first-class and business-class sections. But some carriers may want to create high-capacity versions, as some have done with Boeing Co.'s 747 jumbo jet. The 747 can carry as many as 524 passengers in a two-class configuration but usually carries around 416. The A380s with fewer seats won't have to undergo an evacuation test so long as Airbus can pass the test with the maximum 853 passengers.

 

In recent decades, aircraft manufacturers have worked closely with regulators to improve the odds of a successful evacuation. Many of those changes came in response to lessons from actual accidents. Despite the improvements, evacuation planning still vexes manufacturers because it's impossible to fully control or predict passenger behavior. In real evacuations from smoke-filled cabins, for example, some people still try to get their bags from the overhead bins.

 

Equally vexing is the design of the evacuation test itself: It must be a realistic simulation of an accident, but after a test in 1991 that left a volunteer with a broken neck, everyone is careful to avoid excessive risk for the participants. Setting up the A380 test has required years of debate among regulators and months of planning.

 

Airbus is owned by European Aeronautic Defence & Space Co., a Franco-German company, and Britain's BAE Systems PLC. The two, together with industrial partners and European governments, are investing more than $12 billion in the A380. Airbus has 137 orders for the passenger version of the plane.

 

U.S. and other authorities require that for every commercial jetliner with more than 44 seats, all passengers in an evacuation test must be able to get off in 90 seconds using half the available exits. Authorities figure that's about how long most passengers would have to escape a fiery airplane wreck before succumbing to flames or smoke.

 

Evacuation testing became a serious issue after two accidents in the 1980s. In 1983, half of the 46 people on board an Air Canada plane died after an emergency landing in Cincinnati. Two years later, 55 of the 137 people on a British Airtours plane at Manchester Airport in England died in a fire after an aborted takeoff even though more than half of the plane's exits were available for more than two minutes. Regulators realized that their tests hadn't simulated real chaos.

 

One of the people who pushed for greater reality was Helen Muir, a professor of aerospace psychology at England's Cranfield University. Standing in her office she flipped on a videotape of a traditional evacuation test. The crowd looked rushed but orderly. Then she popped in footage of a test in which several people frantically try to squeeze into an escape hatch at once. The difference: Participants in the second test were offered a GBP 5 note for being among the first to leave the airplane.

 

"Horrific, isn't it? And this is just for five pounds," says Muir. "Put a little smoke in the cabin and you think you're going to die."

 

From experiments such as these, manufacturers modified aircraft. On single-aisle jetliners, the rows next to the exits over the wing have more space between them so passengers have extra room to escape. Jet makers are now required to install emergency floor lighting. To reduce the chance of toxic smoke, airplane makers have upgraded the plastics and synthetic fibers in walls and seats.

 

Evacuation tests can be dangerous. According to Federal Aviation Administration data, nearly 15 percent of volunteers get injuries such as sprained ankles. Yet regulators have balked when plane makers advocated using computer simulations. "All of the computer modeling in the world is not going to give you what you'll get in a test," says the FAA's top official, Marion Blakey.

 

In a 1991 test of a McDonnell Douglas MD-11 inside a darkened hangar at Long Beach, Calif., one attempt took 132 seconds and resulted in 28 injuries. McDonnell Douglas did the test over and got people to move faster. But in the mayhem, a 60-year-old woman caught her foot on a slide. She flipped, crashed headlong against a pile of people at the bottom, and broke her neck. She was left paralyzed for life. McDonnell Douglas failed the test and the FAA denied its request to put up to 421 people on the MD-11. (It eventually approved up to 410.)

 

The centerpieces of any evacuation are the giant inflatable slides. Each slide must shoot from its tightly packed container and be ready for use within six seconds of a door opening, even after freezing at minus 65 degrees Fahrenheit. The slides must stay usable amid high winds and flames. They must not collapse if passengers pile up at the bottom. Some also must double as life rafts.

 

The slides for the A380's upper deck have an added feature. Normally they stretch about 40 feet. But that might be insufficient if the plane comes to rest at a strange angle or tips up on its tail. In such cases onboard sensors will automatically trigger 13 additional feet of slide to inflate on some of them.

 

Airbus awarded its A380 slide contract in July 2001 to Goodrich Corp. of Charlotte, N.C. Goodrich built a hall at its Phoenix plant to test the A380 slides including chambers for extreme hot and cold and a swimming pool outside to test the slides as rafts. Six Hollywood wind machines simulate storms. Test rigs replicate sections of an A380 exterior, including one with a platform 26 feet up, equal to the height of an upper-deck door.

 

Goodrich has conducted simulated evacuations on each type of slide for more than a year as part of its own testing. The company brings in employees for some runs. But regulators demand novices for important tests, since most people never go down an airplane slide in their life. By the time regulators certify the slides, they will have been deployed a combined 2,500 times, says Christine Probett, president of Goodrich's aircraft-interior-products division.

 

Test jumpers wear helmets and tape their ankles like football players to prevent injuries. Goodrich is allowed to intervene only to help subjects clear away from the bottom of slides so others don't crash into them. Regulators say passengers spontaneously do this in real evacuations.

 

Goodrich's tests have inspired several tweaks. Designers built inflatable side rails to prevent passengers from falling off and adjusted the length of some slides to make them less steep. They also found that adding a small porch-like area just outside the jet doorway on some upper-deck slides lets passengers gather their courage to jump and prevents queues inside the plane.

 

Last weekend, Goodrich was testing another feature that is now mandatory on new planes: built-in light strips that illuminate the chute so passengers don't feel as if they're jumping into a bottomless pit. In the latest tests, it turned off all the lights in its test hall to simulate "dark of night" conditions.

 

Still, A380 planners realize the upper-deck slides may prove imposing, especially to frail or novice fliers. An elderly woman, for example, would be assisted by cabin crew if she balked at the door, "but at some point she would just be pushed," said Manfred Bischoff, co-chairman of Airbus parent EADS.

 

As slide tests proceeded last year, a trans-Atlantic debate simmered about how to conduct the full-scale A380 mock evacuation. The plane's two decks are connected by two staircases. The upper deck can carry up to 315 economy class passengers and the lower deck can hold up to 538.

 

Airbus A380 Safety Director Francis Guimera says that in assessing the two cabins, Airbus looks at the plane "like two separate aircraft." It works on the assumption that in an accident, the stairs wouldn't be usable and all 315 upper-deck passengers would have to leave from that deck.

 

Guimera and his colleagues thought a classic one-shot evacuation test might not be the best method for the A380. Airbus worried that if lots of test participants on the upper deck ran down the internal stairs before escaping, the lower deck might get too congested, while top-deck exits wouldn't show their potential. Airbus proposed instead conducting separate tests for the upper and lower decks.

 

European officials agreed but U.S. regulators balked. Considering the A380's size, says Blakey, the FAA administrator, a full-scale test carries a "certain show-me quality" that will add to public confidence in the plane. In December, Airbus relented and agreed to a single test of the whole plane. It is still working with regulators to figure out what to do if many people use the stairs. In that case Airbus might have to repeat the test or shut the stairs and do a test of the upper deck alone.

 

Airbus engineers in Hamburg began conducting preliminary trials late last year. More recently they have distributed fliers in health clubs across town seeking volunteers for the big test. Mr. Guimera says Airbus is targeting people in good physical shape to avoid injuries. At least 40 percent of the passengers must be women and 35 percent must be over age 50 to simulate a typical planeload. Each participant will receive about $65.

 

As a precaution, Airbus may place cushions beneath some upper-deck slides before starting the test in case a slide collapses and people fall over the side. And to avoid accidents it will be allowed to place dim lights at the bottom of slides.

 

On the big day, which is yet to be set, volunteers and crew will board the plane as almost 250 regulators, Airbus technicians and medical staff get into position to observe and assist. On a signal, flight attendants - recruited from a real airline - will throw open doors and herd passengers to the nearest available slide. For 90 seconds, Airbus executives will hold their collective breath.

 

 

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Guest Guest

Very interesting all right, I would love to see it. :D

 

That is a lot of people to get out in 90 seconds :roll:

 

Airbus were trying to prove they could do it with a computer simulation, because they claimed it would save injuries and possibly even a death or two, but the Authorities in particular the FAA are insisting on a real evacuation. :shock:

 

I was in the hangar for the Ansett Boeing 767 one, it failed the first time, they just do it again until it passes.

 

Strangest one I have seen was for the Guyana Airways Airbus A300-600, we didn't have a hangar at all in Guyana big enough for the Aircraft, so it was done out on one of the taxiways in daylight. :shock:

 

It still managed to pass somehow though. :roll:

 

 

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Guest Glenn

So what happens if they can't get passengers out in 90 seconds during the test?

 

The slide on the upper deck is around 26 foot high. At that height you would be hoping you could stop when you reach the bottom.

 

I'm longing for the day the A380 makes its Sydney debut because I'll be there, Hopefully.

 

 

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I would guess it would be like the Ansett B767 one I mentioned.

 

They will keep doing it until they get it right. :roll:

 

 

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