PCA SDR

The April 2005 issue of Grassroots Motorsports has an article on helmets that might prove interesting to anyone who's getting ready to purchase a new helmet. In a sidebar to the main article, there is a discussion of the use of helmets in vehicles with active airbag systems. They quoted a statement from SCCA Technical services recommending that drivers should not use a full-face helmet in a car with an active airbag due to the risk that the expanding airbag can strike the chin area with sufficient force to cause fractures of the jaw.

I prefer an open-face helmet for AX and a full-face helmet for higher speed events, but I don't have to worry about airbags in my car.

Carl,

Do you know if that is a risk based on some data, or is it just someone who perceives it as a risk? It seems that there is a lot of religious issues around the use of airbags on track, and that this could just be yet another off-the-cuff remark about safety.

Personally, I'm in the same situation as you as I now have a full-face helmet for the track, but I still like the open face helmet at autocross. I do have airbags though, and it doesn't make sense to me that I should feel less safe with a full face helmet.

Anecdotely, it seems to me that an airbag should give you a measure of protection against a basilar skull fracture in a high speed impact, and that a full face helmet should provide more protection from just about everything from car parts to fire. But, like most of the other things I've heard, I don't have any data to back that up.

Bob

I do not have any data to say this is an issue or not,but I can direct folks to the rennlist racing forum since there were many good points made around this topic a month or so ago.

Purely without data, I would have to agree with Bob. I don't see how you can be hurt worse, straped in with 5 points, held back wearing a helmet, versus being thrown into the airbag without a helmet. If the accident is bad enough that your head is thrown near the wheel while belted in with 5 points, I think a broken jaw might still be acceptable.

What causes the jaw to brake? The helmet being knocked off?

I haven't kept up with the thread on Rennlist (as Kary mentioned) nor read the article Carl cited. But I think it has to do with the airbag catching the helmet under the chin (i.e. upper-cut) and having a "hook" to grab on its way up rather than just deflecting off your face. Thereby pulling your helmet up and over your head (or at least trying to) vs. just having an ugly case of road rash...

Jad wrote:Purely without data, I would have to agree with Bob. I don't see how you can be hurt worse, straped in with 5 points, held back wearing a helmet, versus being thrown into the airbag without a helmet. If the accident is bad enough that your head is thrown near the wheel while belted in with 5 points, I think a broken jaw might still be acceptable.

What causes the jaw to brake? The helmet being knocked off?

Jad
I believe it is very possible to hit your head on the steering wheel even with 5 points.
The reason I say this is because I viewed a video on rennist where a guy crashed on the track out at turn 11?at laguna seca and when he hit the wall which was not that hard he actually hit his head on the steering wheel when you watch the video in slow motion.

The other reason I know he hit his steering wheel with his head is he discussed in the thread the fact that he broke his steering wheel as a result of hitting his head on the steering wheel!

Quite amazing but true.

It seems to me the big risk may be the airbag catching the bottom of the helmet and shoving your head backwards, causing a neck injury. If your helmet fits correctly then pushing your helmet into your jaw and breaking it seems unlikely. Of course there are large g-forces in play during a serious (read high speed) accident and anything is possible. Some real world data from sled testing, or even some verified stories of where this has happened, would be very helpful.

The Rennlist thread was interesting but had no real-life anecdotes relayed or any testing other than some mention of an F1 test which does not necessarily relate to sports cars in speed, structure or driving position.

The main article in GRM contained a lot of useful information for anyone in the market for a new helmet and the discussion on airbags was just a sidebar. But I'd not heard this concern before and thought it interesting that the SCCA is actually concerned enough to issue a formal recommendation against use of full-face helmets in cars with active airbags. The article states that SCCA is currently considering more restrictive language and suggests that questions be addressed to SCCA 800-770-2055.

The article mentions that "research has shown" . . . blah, blah, blah. But it doesn't explain what kind of research or data is available nor does it cite any references. It simply mentions SCCA concerns, provides a couple of quotes from concerned individuals, and directs the reader to SCCA for more info. Interesting, but not too satisfying.

I knew someone back when who had a 944 turbo and the airbag(s) went off on hard braking, on the track when he was wearing a helmet.

He wasn't hurt, but he sure wasn't happy! NE1 else hear of such airbag deployment?