SCCA may ban full-face helmets in airbag cars

[altiain]

From the Maverick PCA mailing list:

It has been brought to the attention of SCCA Technical Services that the use of full-face or closed-face helmets while driving vehicles with active airbag restraint systems may result in injuries in the event of a crash that deploys the airbad. Because of the location of the steering wheel relative to the driver's position, the airbag axis is on a level with the driver's chin. In a crash with airbag deployment, contact with the chin area of a full face helmet can be so powerful "that the risk of fractures to the jaw cannot be ruled out" (Hubert Gramling, FIA Institute, FT3?AF, 18.5.1999). This applies to vehicles that may be used in Solo, RallyCross, High Performance Car Control Clinics, etc.

Therefore, it is highly recommended that full-face helmets not be used in vehicles with functional airbag systems. Potentially more restrictive language is currently being considered for 2005, which could appear in an early 2005 issue of FasTrack. If you have any questions, please contact the SCCA at 800.770.2055.

Reference: http://www.scca.com/_Filelibrary/Fil...agAdvisory.pdf

Well, that just sucks. I wonder if the SCCA will see fit to reimburse me for a portion of the $400+ I spent last year on a full-face rig.

Better yet, let me take the guvmint mandated explosives out of my Stock-class car, instead of making my safety equipment obsolete. I would have done this already long ago, were it not for Stock restrictions.

[onething]

OK Mr. Engineer, explain to me why this is more of a risk with a full face helmet than with my naked face hanging out as I drive down the street? I read down to the "that the risk of fractures to the jaw cannot be ruled out" expecting them to say fractures to the cervical spine (neck).

Is the chin strap going to smash my mandible?

[EvilSpeeder]

I thought that wording was odd as well. I would be much more worried about a neck injury than a broken jaw.

[altiain]

Here's the way Doug Gill from SCCA Technical Services explained it on the SCCA board:

If a force of 1000 pounds hits a 1 sq in area (1000 psi) and is transferred to a 5” by 5” area (25 sq in), then the force would be reduced to 40 psi. A helmet is basically designed to spread an impact from a relatively small area and transfer it to a larger area. If your helmet hits a roll bar, steering wheel, pavement, etc., it’s designed to spread out the impact more evenly across the head hopefully to be less than the injury threshold.

Wouldn’t the opposite be true? If a pressure of 40 psi is applied to a 5” by 5” area (25 sq in) and is transferred to a 1 sq in area, the force would be 1000 pounds.

As the force of the airbag conforms to a large area of the helmet, it contacts the chin guard first, causing the helmet to lift at the rear, moving away from the forehead and near the chin. The result can be that the chin supports the force that is transferred through the helmet.

If the helmet doesn't rotate (which it does, even if properly fitted) and the chin alone doesn't absorb the increased force, then . . . nothing.

Personally, I don't buy it. Not one single shred of evidence, not one link to a test study, nothing has been offered to back up this dire warning. I guess the SCCA is trying to protect us from ourselves by withholding whatever information was used to arrive at this conclusion.

[OUTRACE]

Kneejerk reaction from the SCCA. The speculation of one man is not reason for a systemic reaction.

As the not-so-proud destroyer of several full faced helmets, let me say that I'll take as much protection of my loveliness as possible.

Based on the "engineering" I read above, I see no accounting for:

1) Forward motion of the helmet/head combination.
2) Momentum, acceleration, and deceleration of same.
3) Helmet deflection upon impact with the airbag.
4) Ability of the helmet to absorb energy from the head/jaw.
5) Conformance of the airbag to the shape of the helmet.
6) Consideration that without the chin bar as an intermediate layer, the high energy airbag will hit you directly in the chin (and cause an injury). DUH.

Further, there seems to be no appreciation of the fact that an airbag doesn't just hit you in the head.

Based on their logic, they should be recommending DOT only motorcycle beenie helmets for the following reasons:

1) Beenie helmets uncover the ears and don't limit peripheral vision in any way.
2) There is no chin bar to contact an evil airbag.
3) DOT helmets are arguably less injurious to the wearer in lower speed accidents, such as might be experienced in AX.
4) It would lower overall costs in the sport.

While we're on the subject of stupid rules, is it true that it's illegal to wear a helmet inside a car and/or a harness belt system on public roads?

[jolberry]

I heard about this a while back..I hope this does not affect Solo2....seriously, what are we going to hit in a big open parking lot that will deploy a airbag. Cones aren't made of concrete.

[POS Racing]

I heard about this a while back...

Yea this post was started back on 11-18-2004, 12:07 AM, nothing like dusting off a 6 month old post!

[channelmaniac]

Cones aren't made of concrete.

Tell that to Altiain! he has a nice dent from one.

[altiain]

Tell that to Altiain! he has a nice dent from one.

Yeah, but I did manage to hit that one broadside at about 70mph.

JRW picked up an almost identical cone-dent at Mineral Wells.

Back on the subject of skid lids... I haven't heard this subject come up at all again this season - apparently the SCCA realized they'd be pissing off a lot of people if they changed the helmet rules this year.

[jolberry]

Yea this post was started back on 11-18-2004, 12:07 AM, nothing like dusting off a 6 month old post!

For some reason this was showing up as a new post on the list yesterday.
At least on my scewy computer. Or maybe I was sleepy and seeing things....