Air Bag Deployment ? What are the required conditions?

[Shankyz]

I have posted a related post a few days back, but never got any replies from anyone, hence initiating a new thread on this topic.

I think this is interesting, when/how the airbags get deployed ? As far as I know, there is one or more sensors, under the bumper, radiator grills , A Pillar etc which detect rapid de-acceleration and get activated in case of an impact. But off late I have seen few cars where the speed was not much, in one case the car got scrapped from the side and no frontal collision happened, but still the Airbags were deployed. I tried to look for any damage to interiors of the car including the dash, windscreen, A Pillars etc. but they seemed in perfectly OK condition.

Is this on the expected lines? Somehow I had the impression that the airbags get deployed on impact at a high speed (>80 kmph), is that correct? Some of the sources I found on googling mention that even a frontal collision at 20 kmph will cause the airbags to deploy, if it does...what is the use/need or justification ?

I don't think anyone is going to get hurt (Physically) in a collision at 20 kmph? Ofcourse financial hit will be there since the replacements will cost >50k and insurance won't cover 100% anyway.

I think some of these Qs may appear silly to the experts on board but it will be great if they share their opinion, experiences.

[Shankyz]

No replies even after 43 views?

[cediafan]

Air bags do not get deployed in case of rear collision, narrow front collision (car hits a street lamp) etc. If the air bags get deployed on such occasions, then there is some problem in the sensors etc. However, air bags do get deployed even when car is going down a slope and hits the ground or gets into a deep pit. In such case there might not be any damage to the A pillar etc. Some of the scenarios you mention do not warrant the deployment of airbags. Airbags should definitely not be deployed under 20 km, but it really depends on the impact of the collision. Your car might be going at 20 km, but some vehicle might hit you at 100 km!!!

[leadf00t]

Originally Posted by Shankyz

even a frontal collision at 20 kmph will cause the airbags to deploy.

I dont think airbags are meant for that..... I beleive if you all strapped up with your seat beats.. a frontal collision of 20kmph should be taken care just by the seat belts.

Airbags are defintely meant for much higher speeds.

[Shankyz]

Originally Posted by leadf00t

I dont think airbags are meant for that..... I beleive if you all strapped up with your seat beats.. a frontal collision of 20kmph should be taken care just by the seat belts.

Airbags are defintely meant for much higher speeds.

Thanks for replying, I know that already and was surprised to see the airbags deployed while there was not much damage (visible), asked the owner who was standing nearby (Perfectly alright, with not a hint of injury anywhere). This guy says, he was going at 40ish and hit another car at the crossing. the other car was a Sumo, which got hit on the side, and there was just a small dent on the side door. Nothing else... look below for the damage to SX4

[Rehaan]

Good thread Shankyz. There are very logical and solid answers to all your questions :

Originally Posted by Shankyz

I don't think anyone is going to get hurt (Physically) in a collision at 20 kmph?

Firstly, the car manufacturer is not willing to take any chances, even if only 0.001% of people really needed an airbag to help them at a 20km/h collision they will design it to deploy in that situation. If they dont, theres a possibility for millions of dollars lost in law suits and bad publicity.

Secondly, your car might be going at 20km/h, but a bus might be coming at you at 50km/h on the wrong side of the road. The combined collision speed is much higher than 20km/h!

Thirdly, dont underestimate the damage that can be caused by a very sudden stop from 20km/h.

Originally Posted by Shankyz

I had the impression that the airbags get deployed on impact at a high speed (>80 kmph), is that correct? Some of the sources I found on googling mention that even a frontal collision at 20 kmph will cause the airbags to deploy, if it does...what is the use/need or justification ?

The airbags deployment doesnt really have much to do with speed. Maybe it only activates after a certain speed (10-20km/h?) but the DEPLOYMENT happens purely due to the rate of DECELERATION that the sensors detect.
- If you drive into a pile of sponge at 100km/h, the airbags wont deploy since the deceleration will be at a fairly low rate.
- If you drive into a bunch of bushes at 30km/h it might not generate enough sudden deceleration for the airbags to deploy
- If you drive into a solid wall at 15km/h the airbags might deploy!

See the triggering conditions here for more info:
Air bag - Wikipedia, the free encyclopedia

cya
R

[adityamunshi]

Are airbags covered 100 % by insurance ?

[leadf00t]

Originally Posted by Shankyz

Thanks for replying, I know that already and was surprised to see the airbags deployed while there was not much damage (visible), asked the owner who was standing nearby (Perfectly alright, with not a hint of injury anywhere). This guy says, he was going at 40ish and hit another car at the crossing. the other car was a Sumo, which got hit on the side, and there was just a small dent on the side door. Nothing else... look below for the damage to SX4

well i really wont say that the damage on a SX4 is from a 20km/h collision..... i have seen accidents on the mumbai bangalore highway(after the expressway gets over on the katraj bypass ) where cars doing close to 80 rear ending Call centre sumos and still sustaining much lesser damage...

Well I personally feel in accidents, drivers tend to quotes the speeds around 20km/h less than they were actually doing. just a way to be safe or keep the blame less on their heads.

Well if you ask me the damage to the SX4 is "big"

@rehaan great explaination.... Thanks... Its your knowledge because of which you guys wear the moderator's cap

[yayaati]

In this thread i would like to post a question:

If your car flips around and the roof gets damaged and you are not wearing a seat belt --- will the air bags open or not?

[Shankyz]

Originally Posted by adityamunshi

Are airbags covered 100 % by insurance ?

50%, insurance companies treat air bags as plastic ..thanks to IRDA

I wonder what is the justification for treating airbags as plastic?

And why 50% depreciation starting from day1 for plastic parts?

Does it mean that a brand new bumper is equivalent to a 2/3/4 yr old bumper and 50% depreciation applies in both cases ?

What is the logic of defining different categories and assigning different depreciation % to them? In my opinion, the depreciation % should be directly related to the age of the vehicle irrespective of whether is's plastic, metal, glass or whatever.

Thanks Rehaan,

I understand and agree with the impact due to a collision being higher in case the other vehicle/object is at a faster pace, I was scared and worried after seeing few cars with the airbags deployed, especially the one which had no frontal damage but was scraped very badly on the side (Driver side I think).

As long as the airbags deploy when there is a real chance of injury, I'm happy with it but can't imagine the airbags getting deployed if I hit a rick @20kmph or a side collision @20-30 kmph in traffic. That'd be totally unexpected and a expense I'd not like to incur.

[gary4gar]

Rather Than Speed, Airbags work on Principal of Force Applied per unit area.


Regarding Airbag deployment, car is designed to take of its passengers.

Take cases of Old age People Driving or Pregant Ladies, The impact of crash at 20kmph would set game for them.