Monday, September 19, 2016

Time To Make Airbags Optional?


For at least a couple of years, we have known that certain airbag inflators made by the Japanese firm Takata have been exploding like small bombs, sending shrapnel into drivers and passengers who otherwise would almost certainly have survived the collisions that set off the airbags.  A recent investigative article published in the New York Times says that at least fourteen people have died as a result of exploding airbags.  There's no good way to die, but getting killed by a defective safety device has to be one of the worst.  And especially if the company making the things was doing a coverup to keep selling them, as the Times reports.

The coverup was revealed in testimony taken as part of a lawsuit filed by Honda against Takata.  The active chemical in many Takata inflators is ammonium nitrate (AN), the same stuff that was responsible for the explosion in West, Texas in 2013.  One of the main attractions of AN is that it's cheap, which is one reason that Takata has historically been so successful in beating out competitive inflator companies.  But AN easily absorbs water and can undergo changes when subjected to heat or humidity that make it much more likely to detonate when ignited.  There's a difference between fast controlled burning, which is what an inflator is supposed to do, and detonation, which is a practically instantaneous explosion that will shatter almost any container.  And preventing AN from detonating involves keeping all moisture away from it for as long as it's in the car, which can be many years. 

Accordingly, automakers buying Takata inflators insisted that the company do very sensitive leak tests of its containers.  These tests involved injecting a certain amount of helium gas into a container before sealing it, and then putting the whole thing in a vacuum chamber attached to a helium mass spectrometer that can detect only a few molecules of helium, which ordinarily is not present in sea-level air.  It's a great system when it's not abused.  But the only problem was that the containers being tested at Takata's plant in LaGrange, Georgia, kept flunking. 

So the engineers decided to fudge the results.  They pumped down the vacuum chamber several times, "testing" the same container repeatedly until it ran out of helium.  Then they checked it off as passing, put new bar codes on it to conceal what they'd done, and reported that the container passed.  One engineer involved in this scheme complained to his manager about the deception, and was told "not to come back to any more meetings."  He subsequently quit the company.

Up till now, it looked like the worst that Takata was guilty of was gross incompetence, but now there is evidence of outright fraud. 

When I blogged about this matter in 2014, I fully disclosed that both of the cars my wife and I drive are affected by the airbag recall.  We are certainly not alone.  It now looks like over sixty million of the suspect inflators are out there somewhere, and at least nine separate carmakers are struggling to manage the most massive and nightmarish recall in automotive history.  Right now I am waiting to hear from our local Honda dealer about a recall notice we received for our Element last July, telling us that the passenger-side inflator was suspect and we should get it replaced.  Only, they didn't have replacement parts yet, so in the meantime, try not to let anybody sit there.  Now and then I still live dangerously and sit in the passenger seat anyway.  I can only imagine what this has done to the resale value of the vehicle.  So we'll hang onto it until Honda gets a replacement inflator for it.  But I'm not exactly happy to learn from the Times article that the replacement inflator may use ammonium nitrate too.

This whole sad situation brings up a question that was supposedly settled back in the 1990s, when airbags became mandatory on new cars in the U. S.  Can we afford the incremental added protection airbags provide in the light of the hassle, and now hazards, they involve? 

In a calculation performed back in 2005, a writer at the libertarian website Freakonomics claimed that he'd figured out how much it costs to save a life with a seatbelt versus an airbag.  I don't know the details of his calculations, but the results are astonishing.  Seatbelts are pretty cost-effective as safety devices go.  It's about $30,000 to save a life with a seatbelt.  Airbags?  Not so much.  They are vastly more complicated and are effective mainly in head-on collisions.  So the cost to save a life with an airbag is—fasten your seatbelt—$1.8 million.  Now this fellow said that $1.8 million still isn't bad by regulatory standards.  If it was my life saved by an airbag, I would be glad that somebody, somewhere spent that $1.8 million.  But that calculation was done before the massive airbag recall happened, and so you would have to add on to that figure however many millions of dollars have been spent by the automakers on the recall, not to mention the time, anxiety, and waste associated with such recalls.  And the isolated but not negligible accidents involving deaths or injuries directly attributable to airbags.  I've heard that some people have simply stopped driving cars with defective airbags.  This is a little extreme, but if you have another car you can use, I can understand.

It has always seemed a little dubious to me to install shock-triggered explosive charges in cars, even if they are proved to be a lifesaving measure.  And now we have even more reason to wonder whether it might not be a bad idea to make airbag use optional.  Because even properly working airbags can be hazardous to small children, I believe some cars were equipped to turn off airbags if the weight of a child was detected on the corresponding seat.  The way things are now, if I knew how to disable the airbags in my cars, I'd do it, but they're so complicated nowadays I'd have to go to half a year of technician school and even then I'd probably end up setting the thing off when I tried to disconnect it.  You shouldn't have to be qualified as a bomb disarmer to work on your own car, but that's the way it is these days.

In the meantime, let's hope that whoever is making the replacement airbag inflators does a really good job this time, and the millions of car owners around the world driving around with potential bombs can get rid of them.  But maybe it's time to reconsider the whole question of whether using airbags is something that a government should order you to do, or something that is best left to the decision of the consumer.

Sources:  The article "A Cheaper Airbag, and Takata's Road to a Deadly Crisis" by Hiroko Tabuchi appeared in the Aug. 26, 2016 online edition of the New York Times at http://www.nytimes.com/2016/08/27/business/takata-airbag-recall-crisis.html.  I also referred to a useful website where updates on the crisis over the last two years have been collected, at http://blog.caranddriver.com/massive-takata-airbag-recall-everything-you-need-to-know-including-full-list-of-affected-vehicles/.  The Freakonomics piece appeared at http://freakonomics.com/2005/07/18/which-would-you-rather-have-a-seat-belt-or-an-air-bag/, and my previous blog on this subject appeared on Oct. 27, 2014 at http://engineeringethicsblog.blogspot.com/2014/10/do-not-sit-here-exploding-airbag-recall.html.

1 comment:

  1. I have wondered much the same. Ballistic safety systems are typical in the aerospace environment (particularly military jet aircraft) but these are highly tested, highly certified and over-maintained. Needless to say that's all far too costly for the commercial vehicle business...so there are a ton of compromises and cost-cutting measures. It is a short trip from a ballistic device (like a belt pre-tensioner) that helps reduce injuries to one (like an airbag that fails catastrophically) that increases injuries.

    Seatbelts are probably the best balance of low technology and low maintenance and low risk of increasing injury for a privately-owned vehicle.

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