What % of airbags don't deploy?

[Sprintey]

OK, not sure if this one has been done before, but...

Relative was recently T-Boned by a senior going through a stop sign. Car was a write off, as was, I suspect, the small car that did the hitting.

Side airbag did deploy in the rellies car, but the word is it deployed but there was no air in it, so the driver hit their head on the side glass and suffered some bruising. Little car doing the T-boning was not so lucky - airbag didn't deploy at all and result was broken sternum.

So that's two from two, and enough to make any engineer raise their eyebrows.

I'd estimate the ages of the cars as at 5 years, and maybe 7 years. Do airbag systems have a used by date? Might as well we all assume they won't deploy?

[Citroënbender]

If the airbag goes off, it goes off. They don't have "stages" other than the physical constraints that constitute the deployment sequence. As in, the charge fires, the gas begins to swell the bag, the cover(s) are violently forced aside, the bag unfolds and the gas reaches maximum volume before escaping through designed perforations.

Many drivers don't sit in their car properly, they hunch forward so it's possible in a situation like this the pretensioner was unable to effectively pull the person back into the bolstering.

[Dr Smith]

Firstly glad to hear all survived.

Several factors to consider here. For the small car where airbag didn't deploy, without knowing speed/force of collision impact may not have been above the threshold for triggering inflation. Or conversely there may have been a fault in some part of the airbags system from sensor to the unit itself.

In the case of your relatives car, inflation is so fast and the shock of the "explosion", dust that seems to fill the car and then once it's realised by the occupants what has happened the actual airbag has deflated. And because the airbag is so violent it can cause brusing as well. Only a camera filming could really show what actually happened.

I wouldn't be surprised if things actually worked as they should however the "shock" of the experience can really unsettle one and what we think may have happened might not be the case.

[burnz]

Originally Posted by Sprintey

OK, not sure if this one has been done before, but...

Relative was recently T-Boned by a senior going through a stop sign. Car was a write off, as was, I suspect, the small car that did the hitting.

Side airbag did deploy in the rellies car, but the word is it deployed but there was no air in it, so the driver hit their head on the side glass and suffered some bruising. Little car doing the T-boning was not so lucky - airbag didn't deploy at all and result was broken sternum.

So that's two from two, and enough to make any engineer raise their eyebrows.

I'd estimate the ages of the cars as at 5 years, and maybe 7 years. Do airbag systems have a used by date? Might as well we all assume they won't deploy?

if both parties are alive then the airbags/car has done it's job..

[Sprintey]

Interesting replies, thanks

[Sprintey]

Has anyone here been in a crash where an airbag did not appear to work?

[Citroënbender]

I’ve been in two where it would not have surprised me if they had deployed.

I think in one instance where I was “the meat in the sandwich” it was the fact of a rearward shunt at exactly the same time as a forward impasse, which checkmated the mechanical trip in the controller.

[danzvtil]

Originally Posted by Citroënbender

I’ve been in two where it would not have surprised me if they had deployed.

I think in one instance where I was “the meat in the sandwich” it was the fact of a rearward shunt at exactly the same time as a forward impasse, which checkmated the mechanical trip in the controller.

So, were you stationery during this incident? I’m no expert, but I’m sure airbag sensors measure deceleration which is different to impact.
If the occupants aren’t moving in the direction of the airbag, then deploying them can be more dangerous than the initial impact.

[Franco Cozzo]

SRS module will do calculations depending on the sensors set off, vehicle speed and other information shared by the ECU to determine airbag deployment.

If they don't go off they didn't go off for a good reason, I wouldn't say its failure to deploy, its done what its programmed to do.

It may have felt like there was nothing inflating it, but it would have inflated and deflated fast enough to do its job, if it stayed 100% inflated it would be like smashing your head into a brick wall - when I totalled my old Focus I got full frontal airbag deployment that happened so quickly it blew my hearing out that I didn't hear them but saw them come out and deflate in a split second and it was like being slapped in the face and some burns from the gasses.

Its horrible, the pre-tensioners in the seatbelt fire and rip your torso back into the seat, all your weight is pressing against this strap across your torso as you're trying to get thrown out of the car because of the sudden stop, your arms and legs do what they want to do and want to fly off, I bashed my knee on the dash pretty hard (thats why cars have knee airbags now) you get slapped in the face by the airbag, burns on your face from the gasses and to top it off the car fills with this powdery stuff that tastes like **** while you are coming to the slow realisation of what just happened and your ride is halal and you have to deal with insurance companies.

The real failures in SRS systems come from the likes of that Takata issue where there was a design fault that was killing people - the casing on the charge degraded and spat out metal fragments into your face and neck at a bazillion miles an hour.



Oopsies - I managed to remove a 1980s Rodeo from our roads perminently though so I took one for the team

[Olbucko]

Originally Posted by Franco Cozzo

Oopsies - I managed to remove a 1980s Rodeo from our roads perminently though so I took one for the team

How was the driver of the Rodeo? I have a 1984 Rodeo KB43, The thought of having a crash in it scares me, it must have a crash rating of about minus 3 stars, even a crash in my XM would be safer

[M&Ms]

If it's a VT / VX Commodore, then the airbags won't deploy 80% of the time.....

[xxx000]

as above, if the airbag deployed then it did inflate

they don't stay inflated and there are many misconceptions about them

the dust from them is often mistaken for smoke

I've been at a prang where a towie on hearing a sound still coming from a damaged car told me "that's the compressor for the airbag" ….hilarious

for them to deploy they need several factors including sufficient deceleration and the correct sensors to 'go off'.

[.:4:.]

So only been in minor rear enders, but over the years have done some reading and my interpretation in lamens terms is airbags are kind of like hot air baloons. They arent sealed but the expanding gasses from the charge chemical (its something like gun powder) when triggered fills the bag quickly but when it starts to cool almost instantly it starts to escape. So if say you get t boned the initial impact yes, the bag has your noggin, but if the car is still rocking about then the bag wont do anything more then hopefully stop glass and debris getting to your noggin. No science behind my thought really, but its things i have read over time that make enough sense to me.