Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site eneevax.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!pesnta!pyramid!decwrl!amdcad!lll-crg!gymble!umcp-cs!eneevax!hsu From: hsu@eneevax.UUCP (Dave Hsu) Newsgroups: net.politics,net.auto Subject: Re: Re: airbags [LONG response] Message-ID: <493@eneevax.UUCP> Date: Mon, 20-Jan-86 11:13:58 EST Article-I.D.: eneevax.493 Posted: Mon Jan 20 11:13:58 1986 Date-Received: Thu, 23-Jan-86 08:44:33 EST References: <294@frog.UUCP> <408@gcc-milo.ARPA> <761@unc.unc.UUCP> Reply-To: hsu@eneevax.UUCP (Dave Hsu) Distribution: net Organization: Imperial Widget Research Center, Kingdom of Maryland Lines: 128 Keywords: Belts forever, the more the better Xref: watmath net.politics:13089 net.auto:9179 Summary: Sorry, try again. In article <1184@mtx5a.UUCP> mat@mtx5a.UUCP writes: >> [ I write ]... >> Also, they won't pin you to your seats. Airbags are designed to inflate upon >> head-on impacts over 12 mph. The plastic bag touches only your chest, NOT >> your head or neck (from a proper seated position) and is arranged only to >> prevent you from being flung into your steering wheel. Observe that if you >> fail to wear your belts, the airbag WILL NOT prevent you from going through >> the windshield at substantial velocities as it is only anchored at the >> hub of your steering wheel. >> >> Along the same lines, they WON'T keep you stuck to your seat. In fact, >> airbags are designed to deflate within 45 milliseconds of inflation, which >> is to say, somewhat faster than most of you can react to the airbag's >> detonation. So by the time your brain has registered that the bag has >> been fired, it's already a collapsed piece of plastic. You'd much better >> be worried about the impact fractures you recieve if you lock your arms >> and legs than from any percieved injury you'll get from an airbag. >> >> Remember people: use your belts and your head, and you'd better have a >> better reason than the ones you've rehashed before you consider disabling >> your airbags. >> >> -dave "why-are-there-so-few-believers-in-airbags-who-may-someday-become- >> customers-for-my-friends-at-the-rescue-squad" hsu > >David: > I believe that you are missing the point. Anything that can hold you >back from impact in a 35 MPH collision by exploding in front of you can rip >you away from the wheel -- or injure you if you are placed improperly. > >Also I DO want something to pin me in my seat ... that's the only way I can >steer OR pump the brakes in a hard panic stop. As far as locking your arms, >I don't expect to have time to ... and if I have the torso restraint I won't >WANT to lock my arms. Without it, I am likely to, since I will be trying to >control my body while braking like a sonovabitch. > >And airbag-equipped cars probably won't have the torso restraint, nor the >necessary structural integrity in the posts to accept the restraint. > >Here's a realistic nightmare: > > [ chaos on ice-slicked Garden State Parkway from driver ahead ] > >The fellow behind me hits me as I slow, and I pick up 8 MPH or so, then >hit the fellow who just bounced off the guardrail. By this time I am >spinning the wheel wildly and punching the gas in the hope of getting >some traction and being able to not hit anyone else. My arm is across >my body, and the impact with the fellow who careened off the rail sets >off the airbag. The impact rips my hand from the wheel, injures my >shoulder, elbow, and wrist. All of this takes place faster than I >can comprehend. > >Now my car is out of control. I am stunned, with one disabled arm. >The car crashes into an overpass support column (necessarily non-frangible) >and I am without airbag and without torso restraint (which was not designed >into the airbag-equipped car) so when the car hits, I slam into the wheel, >which breaks a couple of ribs, one of which punctures my liver. Without >prompt medical attention I WILL die from internal bleeding and resultant >shock. All the staties and all the ambulances up and down the length of >the parkway are up to their teeth in casualties. What are the odds of my >getting that prompt medical attention? My front seat passenger, who slammed >into the dashboard, suffered a fractured skull. He will live, but will not >remember the accident. > >With the three-point harness, none of those injuries would have >occurred. > >By the way, I DO favor the airbag for the passenger, but I want 3-point >harnesses all around. Or 5-point harnesses. With the center buckle, >they'd be easier to use. > >Oh, and the next time you feel embarrased about the belts, remember that >no fighter pilot in the world would go up without his 4-or-5-point >harness. And they don't make'em any tougher than that. That harness >is NOT there for an accident. It's there because he can't safely operate >the aircraft without it. And I feel the same way about the 3-point harness. >-- > > from Mole End Mark Terribile Sorry about including so much text, but I had to leave in the plug for harnesses. Well, Mark, there are a number of reasons your scenario is such a nightmare, and a number of reasons why it would not happen. Firstly, the airbag doesn't operate by pushing you away from the controls. Rather, the object is to inflate the bag before your head reaches the steering column, and to use the bag's deflation to slow yourself down. Imagine jumping into an inflated hot-air balloon, or onto a moon-bounce. This is the design principle behind airbags. The NHTSA conducted tests in the seventies to determine if airbags would make an average driver lose control in an accidental detonation. Test and control subjects were not told if an airbag would go off, nor when. Result: no loss from an ordinary operating position. Of course, if you're steering the car by holding on to the opposite side of the wheel relative to where your arm is, odds are good you won't hold on. But my guess is that you haven't been in a 12mph impact. Good, neither have I. But if you'd like some idea of what it's like, have some friends hoist you about 4 feet off the ground (in a driving-like position, of course) and drop you. In my book, that's good for 16fps minus a bit for air drag, which is somewhat under 12mph. Try to hold on to a steering wheel doing that. Now, imagine if there were a deflating bag between you and the floor. Get the picture? You're more likely to break your arm (shatter your glasses, etc) if it's across your body and you slam into a steering wheel, instead of an air bag. And don't tell me you're not wearing your harness: airbags aren't designed to be effective without them on anyway. You think the car won't be equipped with one? Unless somebody passes something to repeal it, the mandatory seatbelt law isn't just going to vanish, you know. No, I don't support mandatory airbags, and I've stated this many times over. But as added safety equipment in addition to three (or five) point harnesses, I'd rather have it than disable it. The only difference between an accident with an airbag and one without, is that I don't expect to smack anything into the steering wheel, and you, might. And don't tell me that an airbag is more dangerous that your wheel. Use your belts, -dave -- David Hsu Communication & Signal Processing Lab, EE Department University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu CF522@UMDD.BITNET "Vern Vern Vern Vern Vern Vern Vern, you've done it now, buddy..." -Ernest P. Worrell