How useful are Front Airbags?

[MHG]

Originally Posted by anachronix

I hope you got what I meant when I said the frontal collision being the most probable, it doesnt make the other scenarios as improbable.

I agree. But though I cannot back this statement up with statistics, while frontal collisions are most probable, the lethality or serious damage seems to occur most often in a side impact.

Especially in the case of really well built cars like Accord and Camry, a not-so-high-speed frontal collision wouldn't ruffle up the driver too much. But a sideways impact can be lethal if his/her head bangs into the door sideways and there is no airbag to cushion him.

This plus the fact that its relatively easier to avoid a highly damaging frontal accident scenario than a sideways impact scenario.

I hope you get the hang of the angle I'm trying to look at the situation from.

[latentpotential]

Originally Posted by anachronix

Airbags deployed in case of a collision when the passenger is not wearing a seat belt will do more harm than good. ...


No car or vehicle has 100% safety record. As mentioned by one of our BHPians in the earlier post, everything comes at a price, even safety. The curtain airbags, front airbags or anything work based on a scenario. The frontal collision being the most probable scenario in an accident, the front airbags have been made mandatory in most countries except India (for obvious reasons)

Those who are ready to pay those extra $$$ for safety in most scenarios get them and its not like all the airbags would work in every scenario and put you in an airball to safety. The curtain airbags or side airbags or central airbags all come at a cost and they work ONLY when the sensors picks up the required signals to satisfy that scenario to deploy airbags.

The front airbags is still a worthy basic safety feature in cars. I would pay that extra money to have one in my car!

True, Since an Accident that involved family members, where Airbags and ABS saved them from disaster, we have only selected cars with ABS and Airbags.

Originally Posted by sgiitk

My information is Bag deployment is conditional on both the seat being occupied and also the belt being in use. I have read this stated emphatically on this or the other major forum. Someone was involved in an accident and the bag did not deploy, which was attributed to the belt not being worn.

The Belt being used is the signal that allows that specific Airbag to be deployed.

It works like "Closing the Loop".


OT what about the front and rear guards often added onto cars? Do they benefit/ harm? I have seen two types, Metal and Fiber. If someone can share any data around these.

[prasadee]

Originally Posted by MHG

Is it ? Don't many lethal accidents involve head injuries due to sideways impact ? Isn't a curtain airbag as critical as a front airbag ?

Sure front passenger airbags with many stages/zones to adjust for seat and passenger position, Emergency tensioning devices and belt force limiters + side curtain, head curtain and hip airbags would probably be safer. All this would cost a lot more, and also the passengers need to be seated in the proper positions. Imagine a kid with a big slack in the seatbelt poking head our of the rear window and side curtain airbag deploys. It is a lot of hot air that can do some hurt.

Bottomline is that having an airbag is better than not having any. Is it worth whatever is being charged? Market will decide that. Each person has his own scale of what he is willing to pay for safety, brand image, size, quality etc. It is good that more cars/models have airbag option.

[SPIKE ARRESTOR]

Originally Posted by prasadee

Bonnet is designed to crumple and keep the cabin intact as much as possible, not to absorb all the kinetic energy at 60 or 80kmph.

I did not understand the part in bold above, could you please explain?

[audioholic]

Originally Posted by SPIKE ARRESTOR

Spike

In the previous page, there is a statement, about how vehicles which were initially designed without airbags had them as a feature added later, like the safari, scorpio etc. Now were there any changes made to the front structure to enhance the impact absorbing capacity of the car such that airbags could be efficient? I am asking this to you as I feel you are the rightperson to give an opinion/correction. Wont just plonking an airbag be useless or even more fatal, if the chassis is not designed to absorb a frontal impact and for the airbags to act as a supplemental restraint?

[sgiitk]

Originally Posted by latentpotential

OT what about the front and rear guards often added onto cars? Do they benefit/ harm? I have seen two types, Metal and Fiber. If someone can share any data around these.

Se my first post - I mentioned Bull Bars as a menace. The purpose is to pass on the impact to the chassis, and since the crumple zones are disabled occupant safety is not an issue with these fools. There is also a thread on these somewhere. These will almost certainly interfere with AirBag operation.

[kutts]

Originally Posted by abhinavinc

Sir,
AFAIK, wearing of seat belts is not a condition for air bags to deploy. IIRC airbags will deploy anyhow in a frontal collision, another function of the seat belt is that it tries to prevent/reduce the impact of the collision of the fastly deploying airbag with the front passenger, which if not prevented can itself cause serious injury because airbags expand at the rate of knots in case of a frontal collision.

I had a conversation with a MASS service engineer some time back where he was saying that the sensor for the airbag for SX4 was placed at the back of the headlamp assembly, which meant that only if an impact was severe enough to damage the assembly would cause the airbag to deploy. The downside was that "if" the impact failed to hit the sensor on either side, then the airbags would fail to deploy.

[audioholic]

Originally Posted by kutts

I had a conversation with a MASS service engineer some time back where he was saying that the sensor for the airbag for SX4 was placed at the back of the headlamp assembly, which meant that only if an impact was severe enough to damage the assembly would cause the airbag to deploy. The downside was that "if" the impact failed to hit the sensor on either side, then the airbags would fail to deploy.

I would not go by this information. The airbag sensor is placed near the engine mount on the drivers side, next to the apron and on the passengers side, it is placed on the left apron, both sides below the headlamp assembly. If the impact crosses the front bumper and radiator, it is likely to trigger the Airbags. Also, AFAIK, airbags have decelaration sensors and not impact sensors. They need not be 'hit' in order to deploy.

[sgiitk]

Not really. What is sensed is the acceleration (or rather deceleration) and not the impact directly.

[Shiv_1984]

Originally Posted by prasadee

I think you are oversimplifying the dynamics of a crash. Airbags are mandatory in western countries for a valid reason. In countries like the US auto manufacturers are very powerful in terms of lobbying to prevent anything unnecessary from being mandatory.

That said, I recommend watching a crash test videos of cars and the movement of the crash test dummy. The human neck is flexible and fragile, easy to break and cause death. Seat belt will hold on to the torso, but there is nothing stopping the neck and head from violently bending forward/breaking. Humans have a very heavy head. Human reflexes to stiffen the neck from flopping at crash speeds are non-existent. Unless you are Rajnikant who can dodge bullets

There are several such videos here.
http://www.youtube.com/user/firedemon101

Bonnet is designed to crumple and keep the cabin intact as much as possible, not to absorb all the kinetic energy at 60 or 80kmph. Coming to 0kmph from 80kmph may jiggle the neck free.

Commendable Explanation . To add to it, as fas as the front airbags are concerned they are meant to save you from a frontal collision. Considering the Indian mindset, auto companies keep side airbags only for high end models where it can offset the costs.
Just think how the costs would elevate, if a swift ZXI/ZDI have 6 Airbags, Traction control or ESP or all of them. Think what would an i20 CRDI Asta will cost you if they add ESP or Traction control to it, it will be in Honda City AT zone. Same applies with other B2 or C1 segment cars as well.
Safety comes at a price, the price we indians are not ready to pay. We often give reasons of ABS not required because of strict City Usage or Airbags not needed as the car will be driven very sedately etc etc or at least they do not have budget. I will always support a move where Airbags and ABS are made mandatory. Nothing is more important than my family's Safety. Period.

[SPIKE ARRESTOR]

Originally Posted by audioholic

In the previous page, there is a statement, about how vehicles which were initially designed without airbags had them as a feature added later, like the safari, scorpio etc.

Can't say about a Safari but I can comment about Scorpios, as I have seen crash prototypes (of various tests on Scorpio).

Now were there any changes made to the front structure to enhance the impact absorbing capacity of the car such that airbags could be efficient?

Yes, there were. If possible, make a side by side comparison between the two and you will understand.

Wont just plonking an airbag be useless or even more fatal, if the chassis is not designed to absorb a frontal impact and for the airbags to act as a supplemental restraint?

The thing will still work, but not the way it is supposed to be, also, it is not right. Actually, apart from the bonnet and front bumpers, there are many other small things incorporated into the structure to make it crash compliant. The recent crash test I witnessed with a German marquee made me realize it further.

Unfortunately, I cannot share any details on this.

Spike

[LonelyPlanet]

In theory I completely agree with the need.
But there have been enough cases reported in TBHP where the airbag has failed to deploy on some premium cars !!

Example
http://www.team-bhp.com/forum/street...ml#post2875259

http://www.team-bhp.com/forum/street...se-pg-7-a.html

http://www.team-bhp.com/forum/street...rders-fir.html

Are the vehicle manufacturers collecting a premium with the emotional angle - food for thought !!

[prasadee]

Originally Posted by SPIKE ARRESTOR

I did not understand the part in bold above, could you please explain?

I meant a gas engine upon acceleration converts a lot of energy into motion. All of this needs to go somewhere during collision. Some of this energy is in our heavy head, and it needs to be restrained to avoid breaking the neck.

http://en.wikipedia.org/wiki/Kinetic_energy

[SPIKE ARRESTOR]

^^ Hey, that I know buddy. I was asking about the relation between bonnet and energy / speed during a crash, and what actually happens. Since you mentioned a speed range.

Spike

[Arch-Angel]

I'll try and frame up a reply with regards to the thread title:

1. Are front airbags useful ?

The answer would be a yes, but not by itself. The car safety gear is designed to work in tandem with each other . ABS/EBD helps the brakes not locking up, the Seat belts prevent the driver's/passenger's torso from moving forward due to rapid deceleration (read: Inertia due to a human body being inside a moving body). Cars with ABS/EBD will help reducing the chance that the airbags will deploy at all, since you would be stopping before you actually hit something.

As someone had posted earlier, Seat-belts hold only the torso, leaving the head unbound. So, when the car crashes, you have the torso linked with the car(seat-belts holding the person in place) but the head is still in motion. This might lead to a dislocation at the base of the neck.

This is the major reason why safety while driving is a must. Relying on oneself during crisis will always be better than relying on technology during such occurrences.

P.S : sorry for the long post.