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Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!ark
From: ark@alice.UucP (Andrew Koenig)
Newsgroups: net.auto
Subject: Re: Reliability of passive restraints
Message-ID: <4784@alice.UUCP>
Date: Wed, 8-Jan-86 22:43:47 EST
Article-I.D.: alice.4784
Posted: Wed Jan  8 22:43:47 1986
Date-Received: Thu, 9-Jan-86 07:20:09 EST
References: <269@twitch.UUCP>
Organization: Bell Labs, Murray Hill
Lines: 20

> Since an air bag is not tested unless it is used, how does one know that
> it will work when needed?  For those who have air bags, is it convenient,
> or even possible, to test them?  If a seat belt has inertial-lock reels,
> one can test them by stomping the brakes or lunging forward in the seat.

It is impossible to test an air bag without using it,
and they are use-once devices.  However, that does not
mean one should have no confidence in them for that reason.
For instance, it is also impossible to test the shear pins
that hold the engines on a 747 wing.  Nevertheless,
Boeing gets a very good idea about whether or not a
shear pin is likely to work by a simple algorithm:

	1. Make 100 pins in the same manufacturing run.

	2. Pull 10 of these pins at random and test them.
	   This, of course, destroys the pins.

	3. If any of the 10 fails, destroy the other 90.
	   Otherwise, use them.