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