Quote:
Originally Posted by jaykay
Thanks some really good info here!
Pedro: so the edge of a helmet has been found to be worse than a chin; it would give more friction but I would have thought at the velocity of an air bag the friction force generated would be on the same order as a chin...intersesting
Thanks never had heard of this before...
|
When a steering wheel airbag deploys, it is supposed to hit the driver square in the chest to slow down the torso and prevent trauma to the driver.
That's the main reason why Porsche cars don't have an up-and-down steering wheel adjustment, just an in-and-out. Porsche claims that if you are able to move the steering wheel up or down your chest will not be the airbag's target anymore.
They did extensive ergonomic and crash tests to come up with the best solution.
Porsche crash-tested with dummies wearing helmets and 3-point seat belts, in street cars and found out that in some instances, the upper edge of the airbag would catch the lower edge of a full-faced helmet and push it back while the dummy's body was still moving forward.
Driving with a full-faced helmet in an airbag equipped car is more dangerous because the helmet is much wider than your chin and protrudes at least a couple of inches further out so it offers a bigger target for the airbag.
Remember that most helmets were designed for racing applications, where the driver is wearing a 5 or a 6-point harness (in this case it is highly recommended that you also wear a HANS device since your body is strapped to the seat and, in a frontal crash, the only thing moving forward by inertia would be your head.
Also, racecars don't have airbags, so these issues only came up when some manufacturers did crash-testing research under DE conditions.
I saw one of those videos from Porsche and one from Mercedes Benz some years ago when the company that I was running started to look at a safety-helmet manufacturer for a possible merger.
It really wasn't pretty looking at the crash dummy's head go back completely in a more-than-90 degree angle to his body.
From that day on, I've only used an open faced helmet in my airbag-equipped car.
Happy Boxstering,
Pedro