Saturday, March 14, 2009

Airline Safety: Precautions or Placebo?

I've been reading an online discussion of the recent successful ditching of an airliner in the Hudson. If I am following it correctly, this is the first time anyone has succeeded in ditching a large passenger jet. Smaller planes and propeller planes have been ditched successfully but it sounds as though the closest anyone had come before with a full sized passenger jet was a crash landing which some passengers survived.

This raises an obvious question. Very nearly every time you take off in an airplane, even for a flight entirely over land, you get a lecture about life vests, flotation cushions, life rafts, and the like. Is it almost entirely bogus? If, prior to this incident, nobody had managed anything better than a crash landing, was there any significant chance that those precautions would save lives or were they there merely to make passengers feel better?

16 Comments:

At 6:59 PM, March 14, 2009, Anonymous Anonymous said...

Good question, David. I've actually asked flight attendants about just this. Why do you spend time going over the safety procedures for a water landing when (at the time) there had never been a water landing in the U.S. other than a freight transport. They had no answer.

There has now been a water landing of a commercial passenger plane, but still, no need for the safety precautions.

Now, would you move to get rid of the life preservers if you could pull the switch?

 
At 7:27 PM, March 14, 2009, Blogger Nick said...

I heard from a frequent flyer that the yellow life vests were partly for identifying bodies easily after a crash into land. I suppose you don't want decomposing bodies turning up weeks later 100s of yards from a crash site. Obviously, they wouldn't necessarily mention this purpose during the in-flight routine.

I think the Hudson landing plays against these theories to an extent. Perhaps landing on water was always the theoretically best thing to do (i.e. it might work) and now it has!

 
At 7:46 PM, March 14, 2009, Blogger Overboard said...

I like the body theory.
I'm flying on Wednesday. This will give me a chuckle.

 
At 8:01 PM, March 14, 2009, Blogger Micah said...

I've always assumed it was because a government regulation requires them to do so. The short explanation is exactly the same no matter the airline, so a regulatory answer seems most likely.

 
At 10:48 PM, March 14, 2009, Anonymous Mike G in Corvallis said...

Suppose the next time there's a forced water landing, some of the passengers are killed or injured. If it came out that the flight attendants *hadn't* given the safety lecture, I'd think that would be very bad publicity for the airline (on top of the fact that the accident occurred in the first place, of course).

Even after a century, people still remember that the Titanic didn't carry enough lifeboats.

 
At 10:57 PM, March 14, 2009, Blogger eclectic said...

This comment has been removed by the author.

 
At 11:02 PM, March 14, 2009, Blogger eclectic said...

Well, according to this site, your initial information is incomplete. They cite 179 ditchings of commercial passenger planes, including several in American waters, with a high survival rate, though the Hudson landing was still exceptional in several ways.

 
At 10:56 AM, March 15, 2009, Blogger Michael Kolczynski said...

The problem is that of sample size. How many opportunities do we have where someone has been able to try to accomplish such a thing?

Out of all the plane crashes that have ever happened, how many were of the type where this kind of emergency landing were possible? Of those, how many were successful? Is it one out of 3, one out of 10? one out of 1000?

A better question may be: how many times have passengers actually had to use one or more of the following: emergency air bags, emergency exits, or seats as "flotation devices" to save their lives?

 
At 10:58 AM, March 15, 2009, Blogger Chris Hibbert said...

Given that the spiel is canned and consistent from airline to airline, and hasn't changed since it was first written (Southwest makes a point of making fun of the fact that they aren't allowed to change the "explanation" of how to use a seatbelt) I'd guess that it was written by a bureaucrat, and that no bureaucrat since has been willing ot make a change in case something in the change might turn out to cause a problem of any kind later. I doubt that evidence had much to do with it originally, and since it hasn't every changed, there's clearly been no review.

 
At 1:44 PM, March 15, 2009, Anonymous Anonymous said...

The wording of the spiel is specified by the FAA. I am not fan of this government agency, however the contents is generally based on research from human factors and the results of previous accidents.

For example, you are instructed to not inflate your life jackets inside the aircraft. The reason for this is based on the happenings when an Ethiopian airliner crashed. It was hijacked, and ran out of fuel over Mumbai, and crashed just off the beach. It is pretty famous because it was caught on several tourist cameras.

However, during the crash, many people survived the impact. Since it was in water, many put on their life jackets and inflated them. Unfortunately, as the cabin filled with water, they floated to the top and had very limited mobility, so death by drowning was one of the major causes of mortality in this accident.

The truth is that with most crash landings, it is quite common for many people to survive the crash (since generally speaking the plane does glide rather than hitting nose first.) Many deaths occur after the crash from fire of suffocation and so forth. Particularly so since a common injury from the crash is broken legs, preventing egress.

Anyway, the bottom line is that the spiel is based on some deep research.

Of course, I am no fan of the FAA, we would certainly be better with private organizations to ensure air safety, but, of all the things they do, I think this one is pretty defensible.

 
At 5:42 AM, March 16, 2009, Anonymous Anonymous said...

John Adam's blog (a lot of his work is concerned with seatbelt law) recently mentioned this subject. http://john-adams.co.uk/2008/11/05/proving-a-negative-and-the-onus-of-proof/

 
At 3:01 PM, March 16, 2009, Blogger Seth said...

The warning and life preservers are a lot more likely to save lives than to kill people. Therefore, given their negligible cost, it's the right thing to do.

 
At 3:44 PM, March 16, 2009, Blogger Chris Hibbert said...

If the cost is high enough and the lives saved small enough the fact that they don't often kill people doesn't matter. Remember that the airlines use up space with the life vests and take up a minute or more of every passenger on every flight and have done so for something like 40 years. That's a lot of time to waste if it's not doing any good.

 
At 9:22 AM, March 18, 2009, Anonymous MikeP said...

If you want an example of an airline safety system that has actively killed more people than it has saved, take a look at the passenger oxygen masks.

Those who have looked into it cannot find, in the entire history of aviation, a single death or injury prevented by passenger oxygen masks. Pilots have their own separate masks, and the immediate response to any cabin decompression is an emergency descent to breathable air. There is simply too little time at high altitude to do most anyone any harm.

But the requirement that airlines handle the canisters that supply the passenger oxygen masks was the first of the long chain of errors that cost the lives of the 110 people aboard ValuJet 592.

 
At 1:26 AM, April 08, 2009, Anonymous LarsE said...

The Economist some time ago wrote about this (sorry cannot find the reference). Their two main comments was that you were asked to bend down to preserve make dental identification easier as well as (already mentioned) that life west were for identifying you corpse in the forrest.

 
At 8:45 PM, May 15, 2009, Anonymous Anonymous said...

They work in theory, but for obvious ethical reasons they have never been fully tested. Untested doesn't mean placebo, it just means untested. For ethical reasons, I hope it remains so:P

 

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