Lessons From Flight 214: Should Airplane Seats Have Shoulder Belts?

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Marcio Jose Sanchez / AP

A United Airlines plane passes on the adjacent runway next to the wreckage of Asiana Flight 214

They’re already available on some flights, but only in business and first class.

Among the list of injuries suffered by passengers of Asiana Flight 214 were head trauma, spinal fractures and “road rash,” a tally that reflects the tremendous battering that the 291 passengers and 16 crew members endured as the Boeing 777 clipped a seawall, lost its landing gear and skidded, nearly flipping over, into San Francisco International Airport.

Remarkably, more than 120 were able to walk away, and did not require medical care. And for that, they may have had their seats, and their seat belts, to thank. After loose seats contributed to injuries in plane crashes in 2012, some airlines have reinforced the track to which seats are bolted, preventing them from getting pulled away and collapsing on passengers during rough landings or crash situations.

And the seat belts that flight attendants urge you to wear during most of the flight also helped to keep head and neck injuries to a minimum, says Dr. David King, a trauma surgeon at Massachusetts General Hospital and an assistant professor of surgery at Harvard Medical School. “Clearly for the vertical deceleration [typical] of an airplane crash, the lap belt seems to be the most important restraint,” he says.

But would a chest strap, like the ones now required in cars, have further reduced injury? “We don’t know the absolute benefit of adding a shoulder restraint to that kind of crash dynamic,” he says.

(MORE: Why the San Francisco Plane Crash Was Survivable)

That’s because there isn’t the same volume of studies on the effects of shoulder straps and whether they improve outcomes in plane crashes as there are for car accidents. And that’s something to be grateful for, since the dearth of data is a direct result of the infrequent number of airplane crashes. “We have reams and reams of data, and decades of experience on car crashes, and on the utility of seat belts in all sorts of different crash configurations,” says Dr. Carl Schulman, director of the William Lehman Injury Research Center at the University of Miami Miller School of Medicine. “We don’t have that same data for airplanes.”

But if the lap and shoulder restraints protect passengers from serious injury in car accidents, why wouldn’t they do the same in a plane crash? For one, the forces involved in an airplane accident are entirely different from those that generally cause trauma in vehicle collisions. Car accidents (as long as the vehicle doesn’t flip) generally occur on a single, horizontal plane, and the forces are relatively predictable — they can launch a driver or passenger forward, backward or to the side. Before lap belts were mandated, the most common cause of injury or death was head trauma sustained when the passenger or driver was ejected from the car by the force of the collision.

In plane crashes, potentially life-threatening forces can also come from another plane — the vertical axis, causing spinal and skeletal injuries. And while it makes intuitive sense that more restraint with a shoulder harness would keep passengers from being jostled around and exposed to more damaging trauma, there simply isn’t the data to support that adding a chest strap would protect passengers significantly from further injury. “I find it difficult to imagine that having additional restraint offers no benefit,” says King. “The question I would ask is, ‘Is the magnitude of that benefit justifiable by the expense and the other effects a shoulder belt would have on safety?’” For example, he notes that unbuckling a shoulder harness may add a second or more to a passenger’s ability to evacuate the plane, and in the case of Flight 214, that might have meant the difference between surviving and being caught by the fire that spread through the cabin.

(PHOTO: Inside the San Francisco Plane Crash)

In addition, shoulder straps are only effective if they are anchored to a structurally sound object, which means they likely wouldn’t be helpful if they were rooted in the chair itself. Most shoulder harnesses in cars are connected to the frame of the vehicle to ensure that they don’t come loose from the impact of a crash. In planes, that would require some redesign of the seating “bench” to ensure each shoulder strap was solidly anchored to the aircraft.

And because it’s not known how much added safety benefit a shoulder harness would provide, it’s impossible for regulators to make any evidence-based assessment about whether they should be added to airplane seats. Lap belts and shoulder belts were mandated in U.S. cars after researchers showed that the odds of surviving a car crash were higher among those who used the restraints than among those who did not. “That data led to one irrefutable, absolute truth,” says King. “If you are in a car crash, wearing a seat belt will mean you are more likely to walk away alive than if you were not wearing a seat belt.”

There is a tradeoff for that benefit, however, and since seat-belt laws were enacted in almost all the U.S. states, doctors started to see a different kind of injury from crashes. “We traded being ejected from the vehicle, and perhaps getting a serious brain injury or dying, to having injuries that are sort of survivable,” says Dr. Thomas Scalea, physician in chief of the R. Adams Cowley Shock Trauma Center at the University of Maryland Medical Center.

That was the case for many of the passengers on Flight 214 as well. In addition to the head injuries and spinal fractures that the emergency-room doctors treated were abdominal injuries, which can be attributed directly to the lap belts that kept passengers strapped to their seats. These injuries are becoming familiar enough to trauma doctors that they have a name — the “seat-belt sign” — which refers to the abrasion and contusion caused by the belt on the belly.

(PHOTOS: Boeing 777 Crash-Lands at San Francisco Airport)

The seat-belt sign is a red flag for potentially dangerous internal damage, says Schulman. “It’s about physics. When you have rapid compression of the seat belt pushing against hollow organs such as the stomach, colon and intestines, it can cause them to rupture, similar to a balloon.”

Most trauma physicians would much rather see these types of injuries, however, given the alternative. “The reality is that an abdominal injury from a seat belt — a ruptured intestine or liver — is more easily amenable to repair whereas a brain or neck injury is more often permanent or even fatal,” says Schulman.

What they would also like to see is better information about the types of forces their patients experience during crashes, whether they occur in a car or on a plane, says King. The medical literature is filled with case studies of victims who were involved in serious car accidents and refused medical care, believing they were fine, only to die a day or so later of undetected injuries. Traumatic injuries are almost directly related to the amount of force that a person is subjected to in a crash — the drop in velocity when a car collides with another vehicle, or with an embankment, or, in the case of an airplane crash, the sudden deceleration when a plane suspended in the air crashes to the ground. “That number alone is highly predictive of severe injury,” says King.

A relatively low change in velocity, for example, might mean that the victim likely doesn’t have internal injuries since the force of the accident simply wasn’t high enough to generate such harm. But greater and sudden changes in speed — dropping from 50 mph (80 km/h) to a standstill, for example — are more likely to cause serious trauma and require intensive evaluation and imaging tests of the brain and internal organs. Having this information would be helpful for trauma surgeons triaging victims of accidents, to determine which patients need more monitoring and which can go home. Cars currently have such decelerometers, and some researchers are working with manufacturers to develop handheld devices that EMTs can use to download the information at the accident site and relay it to emergency-room doctors along with the patient’s vital signs. Installing decelerometers under plane seats might also provide this information for plane-crash victims as well, says King.

Whether additional shoulder harnesses would have reduced some of the head or spinal trauma that some of the 19 passengers on Flight 214 who remain in critical condition experienced isn’t clear. But one passenger who walked away from the crash, Eugene Rah, told CNN he believes it might have saved him from further injury. The Boeing 777 included shoulder straps for seats in first class, and Rah said the chest belt kept him stable during impact. “If I did not have that, I would have hit the ceiling, that’s how hard [the impact was],” he said.

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20 comments
tjd
tjd

I don't think the seat belts are really there to save you from injury, but to simply keep you in the seat and not flying around the cabin if the plane is out of control.  I'm glad to hear some airlines are trying to make them and the seats better though.  A Mythbusters episode showed how average seats could crush your legs in a simple 10 foot drop.

notLostInSpace
notLostInSpace

@tjd Keeping you from flying around the cabin in turbulence actually prevents zillions of injuries!

ilikeike
ilikeike

People need to listen to flight attendants when they tell everyone before taking off where the exits are!

notLostInSpace
notLostInSpace

@ilikeike You mean the little sausage tube holes near the wings, rear, or front, and no where near where I sit, even if I can get past the other people that will flood into the aisle (and immediately fall on top of each other) along with all the crap from everywhere (overhead, under seats, drink carts), in the dark, in smoke that is highly toxic?  Frankly, I don't want to be reminded that I am in a very difficult position if something bad happens.  I think most survivors of crashes can thank luck, not their paying attention to the instructions (although I have read several "How to Survive a Plane Crash" articles and they do have some merit (mostly being sit next to the emergency door, in the rear, and do not fly in bad weather or night time, do not sleep and do not be alcohol impared). 

rpearlston
rpearlston like.author.displayName 1 Like

First, lap belts, worn properly, do not cause abdominal damage in most crashes.  But worn properly does not mean wearing them over your abdomen.  It means wearing them across what is called the lower abdominal fold, the area at the base of your abdomen, just above the base of the pelvis.  The pelvic bone is strong enough to take the force of many crashes.

But shoulder restraints in addition to lap belts would mean that most women (and some men) will not be protected because shoulder restraints ride up on a woman to the point that they can begin to cut off circulation to the brain.  How would discrimination, largely by gender, help here?

MargaritaHinksoni
MargaritaHinksoni like.author.displayName 1 Like

"Should Airplane Seats Have Shoulder Belts?" More to the point - should airlines put inexperienced pilots in command of intercontinential flights?  Using competent and experienced pilots is better than strapping passengers down with another set of belts, they won't even need the belts.


rpearlston
rpearlston

@MargaritaHinksoni They weren't inexperienced.  

MargaritaHinksoni
MargaritaHinksoni

@rpearlston @MargaritaHinksoni   but with less than 50 hours flying the 777 that doesn't sound like a whole lot of experience to me.  Different types of aircraft have to be learned - it's not like driving a car where they are all pretty much the same.  I understand the captain may have had experience flying other types of aircraft, but was not experienced flying the 777. 

Technia
Technia

Belly injuries from the seatbelt are due to an improperly worn seatbelt.  It should be across your hips, and tight enough so that it will stay put.  If there's an accident, you want your pelvis to take the force, not your guts. 

There are two big stories here that I haven't seen: one is, amazement that so few people died and so many were uninjured, in an accident where the plane cartwheeled, lost its tail, and burned.  If this had happened in the eighties, I suspect we'd be looking at a smoking pile of rubble with no survivors.  What are the safety and material engineering changes that have made this possible?

The other is, why on earth is the media spending so much time on this, and not the Lac-Mégantic accident in Quebec?  Something like forty people died, the center of a town has been devastated, and that accident has huge implications about how we transport oil from our oil sands -- currently via unsafe, old tanker cars on trains.  As I understand it, that was oil being transported from US sands in Dakota to New England, via Canada -- and I haven't seen Canada even say ouch about that.

rpearlston
rpearlston

@Technia There are currently 13 confirmed dead in Lac-Megantic and 40 missing.  But Lac-Megantic is a tiny, scenic town of no particular importance (other that it's scenery) and San Francisco is, well, San Francisco - a major urban area,complete with international air and sea ports.  Besides, when we think of disasters and SF, we think in terms of earthquakes, not plane crashes.

Don't worry - there will be a debate here about how oil is transported.  It won't matter that it didn't come from and was destined for Canada, because that's not the point.  The point is determining the best and safest ways to transport each and every hazardous product.  

notLostInSpace
notLostInSpace like.author.displayName 1 Like

In our namby pamby nanny state, there is rarely any real debate that involves "cost benefit analysis".  How much would the seat belts cost versus how many lives?  What is a life worth.  If you believe in the extreme (to some people) view that cost is no object, then seats should be backwards, in cocoons with air bags, etc. and the average flight cost would be astronomical.  The other side of the horizon is a flying subway with people standing and holding a grab bar to become instant carnage upon a crash, but we could drive down costs.   If you let the marketplace dictate, I bet most people are willing to take the risks as they are presented now.  I for one with the limited flying I do, and my loved ones, already find it too expensive.  The amount of crashes is too low to support more safety belts (maybe we should invest more in pilots as this latest crash is likely pilot error, blame him, not the safety belts for injuries).  I don't think the added benefit outweighs the cost.  I will also suggest, morbidly of course, that very few crashes have survivors that were saved because they were wearing a seat belt.

RobinDonaldDeVallon
RobinDonaldDeVallon

Sure.... more collision data would imply more study on preventing injuries... however... if shoulder belts are in 1st and business class... what´s the hold up in cabin class.... ?? M O N E Y  ??? We´re still not aiming at safety.... but collecting profits by cost cutting...

bojimbo26
bojimbo26 like.author.displayName like.author.displayName 2 Like

If seats were installed rear facing 90% of this wouldn't happen . All UK military aircraft have rear facing seats , so in emergency you are pushed back into the seat .

RobinDonaldDeVallon
RobinDonaldDeVallon

@bojimbo26 we would stilll have  internal injuries from being thrown out of order.... but they would not be caused by the force of a restraining belt.... Donah..//

RobinDonaldDeVallon
RobinDonaldDeVallon like.author.displayName 1 Like

@bojimbo26 .... True... there is no real scientific objection towards riding "backwards" except folks "don´t like" it ... if the military can force their members so we can force the public... we all pay taxes don´t we.. well most of us..  Donah..//

enforcer17
enforcer17 like.author.displayName 1 Like

@bojimbo26 So do all US military transports, its the stigma of facing backwards that has always kept commercial airline manufacturers from turning the seats facing rearward. A number of trains have rear facing seats, those are always the last to be filled because people don't like the feeling of going backwards.