Thursday, January 21, 2016

Do Planes Really Need Life Vests? They provide psychological comfort, but experts question their value when passengers must evacuate quickly

Life vests must be donned properly to be effective—that includes fastening the waist strap. This rarely happens during emergencies on commercial planes. WSJ's Scott McCartney joins Lunch Break with Tanya Rivero and explains why regulators still require they be carried on planes. 



The Wall Street Journal 
By Scott McCartney
Jan. 20, 2016 12:26 p.m. ET


You may think the life vest under your airplane seat will save your life if the aircraft ends up in the water. In fact, such a thing has never happened in modern commercial airline flying.

Even though life vests have been a routine part of overwater air travel, there are problems with their design that limit their usefulness in crash landings. They are so difficult to find under seats and put on securely in an emergency that only 33 passengers of 150 aboard US Airways Flight 1549 had a life vest after the plane splashed down in the Hudson River in 2009. Only four people managed to properly don their life vest, securing the waist strap so it wouldn’t pop off.

“Current standards are not effective,” the National Transportation Safety Board wrote to the Federal Aviation Administration in 2014 about life vests after the “Miracle on the Hudson.”

“Life vests could not be correctly donned by the overwhelming majority of passengers in an actual emergency when the vests were needed,” the report said.

In most crash landings, safety experts say, it’s more important to get out of the plane as quickly as possible to avoid any fires than take precious seconds to find a life vest and try to put it on. And laboratory tests and actual emergencies have both shown that passengers will give up and flee before actually finding a vest under their seat.

Life vests are really only useful when there is advance warning of a water landing, when planes without engine power glide down from high altitude and passengers have time to find vests under the seat, open pouches and put them on in the cabin before hitting the water. The FAA told the NTSB in 2013 that its test requirements for life vests are designed for “a planned water landing” and are “not intended to represent a forced landing on water.”

But for at least several decades, water landings have universally been the sudden type, not the planned variety. That’s not to say it can’t or won’t happen, and safety experts say life vests are still useful. There’s also a psychological benefit: Passengers would think it ridiculous to travel over an ocean without some type of emergency flotation device beyond life rafts.

Former NTSB investigator Greg Feith says the sudden water landing of Flight 1549 shows why vests are needed—87 people were rescued from the plane’s wings and could have ended up in the cold water. “If you survive and are in the water or the cabin is filling up, you want all the help you can get to stay on the surface,” he says.

Vests weigh a little more than 1 pound each, so a medium-size jet has about 200 pounds of vests onboard. That weight increases fuel burn and emissions. When they replaced paper charts with iPads, airlines reported impressive numbers for fuel savings. Eliminating life vests might save more than 1 million gallons a year just at a large airline like American, United or Delta.

“It’s not a trivial amount” in fuel burn and pollution, says transportation researcher Robert Poole of the Reason Foundation, a libertarian think tank. “It’s worth putting the idea to a credible cost-benefit analysis.”

Another cost: Flight attendants check each row of seats for life vests at the start of each day and before each flight over water. That’s because vests disappear regularly—passengers steal them as souvenirs, airlines say.

Still, the airline industry has never dared float the idea of ditching the vests. The P.R. headache of appearing to value a bit of savings over passenger lives isn’t worth the trouble, industry observers say.

In its investigation of Flight 1549’s landing, the NTSB said 77 passengers onboard retrieved seat cushions during the evacuation. The phrase, “Your seat cushion may be used as a flotation device” is ingrained in the psyche of the traveling public. The NTSB said 45 passengers took their own seat cushion, 27 grabbed a seat cushion from another seat and five passengers found seat cushions floating in the cabin before they evacuated. (In very cold water that can induce hypothermia, clinging to seat cushions is next to impossible, even for the young and fit.)

Only two passengers donned life vests before impact and 10 passengers said they retrieved life vests after the plane hit the water; 21 others said they were given vests during or after they evacuated. Both Capt. Chesley “Sully” Sullenberger and First Officer Jeffrey Skiles said they realized passengers had evacuated without life vests, so they grabbed a bunch from the cabin and handed them out after evacuating.

The NTSB said the crash confirmed earlier research that it will take 7 to 8 seconds or longer to retrieve a life vest from under a seat, but most passengers won’t spend that long looking after a crash, especially if water starts filling the cabin.

There has been a push over the years to make vests easier to put on correctly, and the current FAA requirement is that an adult must be able to don a vest within 15 seconds while seated.

After the Hudson water landing and NTSB recommendations, the FAA’s Civil Aerospace Medical Institute in Oklahoma City conducted tests on different life preserver designs to find something easier and faster to don. CAMI researchers had devised a zip-up inflatable vest that they thought would be more like clothing and thus more familiar to passengers and easier to put on.

But the tests showed nothing was measurably better than the life vest currently used. The only things that made a difference were instructions in the safety briefing—requiring more attention from passengers and delivering greater emphasis on correct usage.

“We found people really can’t get these things donned in the amount of time prescribed in an evacuation order,” says Cynthia McLean, the FAA’s principal cabin safety investigator and one of the authors of the 2014 life-vest study.

She says the best advice is to leave the vest behind in an unexpected crash landing. “We want [passengers] out as quickly as they can get out,” she says, because of fire risk.

Ms. McLean still thinks planes need life vests for planned ditchings, even though “there are very few events that conform to that. I can’t think of one,” she says.

James Hall, former chairman of the NTSB, says vests used in marine safety have improved greatly, “but there hasn’t been cross-pollination in that area.” While vests haven’t saved passengers on commercial airlines, there have been saves from helicopters and small planes going into the water, he notes.

And as long as any plane flies over water, any airplane should have life vests. “To me, it’s just common sense,” Mr. Hall says.

Original article can be found here:  http://www.wsj.com

No comments:

Post a Comment