[simple simon]

CHARLOTTE, N.C. -- NASCAR on Monday tried to figure out why Kyle Busch's HANS device cracked during a spectacular crash at Talladega Superspeedway.

The frustrated driver, meanwhile, was trying to make sense of two hard wrecks that ruined his weekend.

Busch wrecked in Saturday's Busch Series event, when he was hit from behind and his car ended up on its roof before rolling several times through the grass. His HANS device, a NASCAR-mandated head-and-neck restraint system, cracked in the accident.

"It performed the way it was supposed to, but it had a slight stress crack in it after the accident," NASCAR spokesman Kerry Tharp said.

NASCAR sent the device back to manufacturer Hubbard Downing in Georgia for examination.

ESPN.com - NASCAR to look into Busch's cracked HANS device

[simple simon]

this cant be good

[LSC9901]

Did it really fail ???? What would ahve happened to him if he hadn't had it on at all ???

[simple simon]

apparently fail may be slightly a strong word ........ it had a stress crack ...... but that still isnt good news

[Lefty Noob]

If it had a stress crack, the potential for complete failure (i.e. a clean break) is there, which is definitely cause for concern for NASCAR. Look for them to scramble to make the devices even more durable ASAP.

[LSC9901]

Absolutely as they should. Safety MUST be first.

[nascarfan24]

good point! that wreck was pretty bad but it still wasn't even the worst that could happen!

[SteelPhoenyx]

Wow! I hope they can figure out why and fix it.

That it cracked under stress but didn't break is good in a way... look at motorcycle helmets. If a rider gets in a wreck, and the helmet is cracked but his head isn't... it did its job.

I'm glad Kyle Busch wasn't hurt. I can't stand the guy, but I'd hate to see him get badly hurt.

[wingkey1]

'tis not unusual in the least that poly material will show the effects of "stress" when notably stressed. Fair to say there were some notable stresses involved in Mr. Busch's pirouettes. It is actually, to a degree, indication that it is doing its job. Bend without break. "Bend" however does tax the materials structure, first to the point of stretch return, then (typically) elongation decreased return, then boo boo (Toss it).

Few realize that a dropped helmet should be discarded. Minute fractures (stress related) result. It is less ready for the next impact. Consequently, few do so (discard them). There are street cyclist aplenty out there every day with something akin to an eggshell on their head as a result of mistreatment. Not so at pro level where helmets a plenty are used by each driver over the course of a season.

To look for unusual reason/cause for a device to show signs of degradation is wise. This is what is apparently happening. To see signs of stress after a stressful incident - not surprising.

As LSC perceived, the device did not "fail". That would surely be cause for concern.

[PenelopePitStop]

Originally Posted by wingkey1

'tis not unusual in the least that poly material will show the effects of "stress" when notably stressed. Fair to say there were some notable stresses involved in Mr. Busch's pirouettes. It is actually, to a degree, indication that it is doing its job. Bend without break. "Bend" however does tax the materials structure, first to the point of stretch return, then (typically) elongation decreased return, then boo boo (Toss it).

Few realize that a dropped helmet should be discarded. Minute fractures (stress related) result. It is less ready for the next impact. Consequently, few do so (discard them). There are street cyclist aplenty out there every day with something akin to an eggshell on their head as a result of mistreatment. Not so at pro level where helmets a plenty are used by each driver over the course of a season.

To look for unusual reason/cause for a device to show signs of degradation is wise. This is what is apparently happening. To see signs of stress after a stressful incident - not surprising.

As LSC perceived, the device did not "fail". That would surely be cause for concern.

True, but scary. I don't like Kyle, but would hate to see him or any driver hurt.

While we're on the topic of safety, didn't he flip? I thought those "flaps" prevented that???????

[SpaceCadet]

Originally Posted by PenelopePitStop

While we're on the topic of safety, didn't he flip? I thought those "flaps" prevented that???????

I think the flaps are to slow the car down if it gets turned around backwards. I don't believe there's too much you can do of it's going to flip. Those puppies get just a little airborn and wow, what a ride. Somebody correct me if I'm wrong about the flaps. I'm an aero idiot.

[PenelopePitStop]

Originally Posted by SpaceCadet

I think the flaps are to slow the car down if it gets turned around backwards. I don't believe there's too much you can do of it's going to flip. Those puppies get just a little airborn and wow, what a ride. Somebody correct me if I'm wrong about the flaps. I'm an aero idiot.

Hmmmm ... I thought the flaps were to prevent the car from getting airborne and flipping. Could be wrong ...








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[simple simon]

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In 1994, NASCAR introduced roof flaps -- a safety device designed to keep cars from going airborne and tumbling over the track. Before this, when the cars spun out at high speeds (more than 195 mph / 324 kph), they would often fly into the air once they had rotated about 140 degrees. At this angle, the car takes on a shape that interacts with the wind very much like a wing.

If the speed of the car is high enough, it will generate enough lift to pick up the car. To prevent this, NASCAR officials developed a set of flaps that are recessed into pockets on the roof of the car. Through wind-tunnel testing, NASCAR determined that the area of lowest pressure is at the back of the roof, near the rear window.

When the car reaches an angle at which it generates significant lift, the low pressure above the flaps sucks them open. The first flap to open is the one oriented at a 140-degree angle from the centerline of the car. Once this flap opens, it disrupts the airflow over the roof, killing all of the lift. An area of high pressure forms in front of the flap. This high-pressure air blows through a tube that connects to the pocket holding the second flap, causing the second flap to deploy. The second flap, which is oriented at 180 degrees, makes sure that the car continues to kill the lift as it rotates. After the car has spun around once, it has usually slowed to the point that it no longer produces lift.

The roof flaps keep the cars on the ground as they spin. This allows the skidding tires to scrub off some of the speed, hopefully allowing the driver to regain control. If not, at least the speed is reduced before the crash.

Howstuffworks "How NASCAR Safety Works"

so there you have it

[PenelopePitStop]

Originally Posted by simple simon

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so there you have it

So it's a combination of slowing the car and preventing it from becoming airborne and flipping. So I guess the flaps failed as well?

[LSC9901]

Originally Posted by PenelopePitStop

Hmmmm ... I thought the flaps were to prevent the car from getting airborne and flipping. Could be wrong ...

Nope you are correct. That is the main purpose of them.