[VaidhiR]

Passive Safety Engineer here and these are my observations.

Modern cars have a plethora of sensors that regulate the volume of air that gets blasted into the airbag, the ventile size opening, timing of firing of the airbag and the time for which the air gets blown into the airbag amongst others. And these are just the starting. Further sensors indicate steering wheel position, seat belt position (in case of height adjuster) and seat position (determines whether the occupant is a short or tall person). And all of this (and a lot more information) is fed into the ECU which calculates, from a complex algorithm, a "rough" profile of the occupant regarding his/her size and seating position. Based on this, an optimal functioning point is determined.

In the front rail, there are usually 3 sensors on each side facing front. The velocity of the impact (and the resulting deceleration) at the first sensor will determine whether or not the "crash" will reach the second (and eventually) the third sensor. But the third sensor is mostly a "backup" sensor in case the two sensors in the front don't function as they are supposed to.

In an ideal scenario, data from the occupant model, that is given to the ECU, is coupled with the sensor data to activate airbag deployment in case of an accident.

There are other scenarios where airbags don't deploy.

1. Not enough deceleration detected at the sensor.
2. Occupant detected, but no seatbelt worn.
3. Electrical glitch occurring due to dust accumulation.
4. Presence of bull bars or other "accessories" that hinder sensor data.
5. Weather phenomenon.
6. Other factors...

In this particular accident, it looks to me, and from the pictures, that the passenger seat wasn't occupied. So it's a given that the passenger airbag wasn't deployed. The driver side airbag should have ideally deployed. From the image that I have attached, the front rail of the passenger, is turned, which means the sensor data would show a moderate movement in either of the 3 axes. And logically any movement of the sensor (in any of the axis) should be sufficient for the airbag to be triggered.

If I remember right, this isn't the first time Toyota Kirloskar is facing problems because of airbag deployment (or the lack of it). A simple google search gave me this result. And the first one that.

Toyota Etios:
https://auto.ndtv.com/news/airbags-d...-dealer-701796

Toyota Fortuner:
http://www.india.com/auto/car-news/t...t-proper-7345/

Also, Toyota Kirloskar has been ordered to pay the customer in a similar case.

https://bangaloremirror.indiatimes.c...w/62420937.cms

All said, I am happy that the occupants of this car got out alive. And this post is not just aimed at criticizing the company here. It is a general warning for people who drive every day on the road.

So people. Please wear your seatbelts. Even the rear seat passengers. It's a tiny piece of fabric. But the importance of it and the levels to which the companies test them, CANNOT be understated. Sometimes this fabric could be the difference between life and death.

[Comrade]

Clear case of truck/trailer not having "Under-ride" guards, and car going under the truck. I think fortuner saved Ram, and same crash in hatchback or sedan might have resulted in more severe damage including human loss.

https://www.youtube.com/watch?v=mrL7AUMT4To

https://www.youtube.com/watch?v=gL8DQIAqZms

[humyum]

I beg to differ here, if a car in this state does not warrant a airbag deployment, I wonder what does?

The owner is right in questioning Toyota as 'What are the spots should someone hit the car on for the lives of people inside to be saved?', I mean look at the damage.

Toyota should really be fined and a big hefty sum paid to the owner.

[roby_dk]

Originally Posted by humyum

I beg to differ here, if a car in this state does not warrant a airbag deployment, I wonder what does?

The owner is right in questioning Toyota as 'What are the spots should someone hit the car on for the lives of people inside to be saved?', I mean look at the damage.

Toyota should really be fined and a big hefty sum paid to the owner.

Can't believe people supporting Toyota on this. It is a sheer case where either the sensors are faulty or they have gone kaput. Looking at the damage where everything is open it is strange the airbags didn't opened.

If such damage is done in low speeds than it is better we should stop calling Maruti cars as Tin cans.

[lazy]

With this kind of damage, there should be simply no justification for non-deployment of Airbags.

Ultimately, the job of airbags is to cushion the driver (and occupants) from the crash. If the sensor didn't sense the deceleration or acceleration or whatever, it points to a faulty design of the whole sensor-airbag electric circuit and logic processing.

cheers
lazy

[Comrade]

This is an industry-wide problem. This has nothing to do within someone being partial/loyal to Toyota or any other brand. The issue is more with truck design than with car design.

From Insurance Institute for Highway Safety article on underride:

LINK

All the improvements in occupant protection that have helped drive down crash deaths in recent decades count for little when the front of a passenger vehicle ends up under a truck. When this happens, the top of the occupant compartment gets crushed because the structures designed to absorb the energy of a crash are bypassed. The airbags and safety belts can't do their jobs, and people inside can experience life-threatening head and neck injuries.

[ach1lles]

This is funny. There's just one variable here, and were that to be different, people would be up in arms here demanding Toyota to make right on this obscene oversight. That variable is the damage to the driver. If he'd been hurt, even moderately, man would Toyota have been crucified here. Anyway, after VaidhiR's post, I don't think there's anything left to discuss.
The airbag should've deployed. Wether that would've caused occupant lacerations, and the driver would've been worse off is immaterial to this discussion. For those, the tech and data need to be further improved. For this, the car and the manufacturer are to blame.

Edit:

the structures designed to absorb the energy of a crash are bypassed

They weren't in this case. Please see the pictures.

[Comrade]

I am assuming underride based on this image. Looks like flatbed has sheared the bonnet, front passenger fender and damaged the passenger A-pillar. It might be this shearing that caused radiator to be misaligned.

I could be wrong but to me it looks like the collision between truck wheel and fortuner didn't even reach the car's radiator.

[ninjatalli]

Guys,
We are debating here basis a highly argumentative and debatable post that has been written out by the car owner to elicit maximum "ooh" factor from all readers. Hardly a factual base to do our discussions here; if we had the owner as the OP, we would have obtained much detailed facts asking questions from the owner.

@Mods - can we change the thread name - highly debatable to keep such the original article's heading out here without clear details available

Originally Posted by humyum

Attachment 1758867

I beg to differ here, if a car in this state does not warrant a airbag deployment, I wonder what does?

Originally Posted by roby_dk

Can't believe people supporting Toyota on this. It is a sheer case where either the sensors are faulty or they have gone kaput. Looking at the damage where everything is open it is strange the airbags didn't opened.

Originally Posted by lazy

With this kind of damage, there should be simply no justification for non-deployment of Airbags.

Originally Posted by ach1lles

The airbag should've deployed.
...
Ultimately, the job of airbags is to cushion the driver (and occupants) from the crash. If the sensor didn't sense the deceleration or acceleration or whatever, it points to a faulty design of the whole sensor-airbag electric circuit and logic processing.

Please understand the logic of why and what the airbag is supposed to do. To simplify it, a vehicle and the occupants are traveling at X speed heading towards a stationary object.

Vehicle traveling at X speed bears the impact of the crash coming to an immediate halt. The structure of the vehicle takes in the impact (and hence our posts on how the frame took the brunt, etc).

The driver and the passengers are still traveling at X; the seat belt and the airbags together are there to bring them to a halt; while minimizing the impact of the force (of stopping) on the body frame. There are multiple factors here - the speed at which the bodies are traveling is a critical point; the airbags won't pop out if you are not hurling beyond a velocity; the seat belts are sufficient to stop you without hurting your body.

However if an object is hurling towards you (in this case being the rear carrier of the truck); the airbags are not going to do anything; the carrier would burst the airbags and still go through your face/body.

This is a very crude representation; experts might be able to give more clarity.

There are too many open points
1. What speed was he traveling when the rear trailer hit the windshield
2. What speed was the car at when the radiator/front hits the underbelly of the rear of the trailer (and impacts the sensors)


Granted - given the lack of information, the default expectation is definitely the airbags should have deployed. But debating if there is a manufacturer fault without having clarity on what happened in the final seconds is pointless.

[Nissan1180]

Originally Posted by ninjatalli

Granted - given the lack of information, the default expectation is definitely the airbags should have deployed. But debating if there is a manufacturer fault without having clarity on what happened in the final seconds is pointless.

The concern here is that airbags did not work when they were supposed to. Such incidents have been posted on other threads for other car makers as well. I think it has something to do with how these vehicles are designed to pass crash tests these days. If you have a crash that mimics the crash test speed, angle of collision, you will be saved by the airbag. If it is not the case, the structural integrity is your only safety feature. Unfortunately, most companies compromise on that simply because the modern buyer thinks (erroneously) that metal strength has no significance in protecting occupants.

The owner lost his car and the driver could have been seriously injured. Let's spare a thought about his state of mind and stop supporting a manufacturer in order to question the owner's intent at sharing the post.

[V.Narayan]

Seat belt? Seat belt? Seat belt!!!

My empathy with the owner and his need to vent his frustration - quite human. But till he confirms and it is technically corroborated (by checking the car's software data) that driver Ram was wearing his seat belt any further discussion is irrelevant. If you are not wearing seat belts the air bags will not deploy - rule 1.01.

Till the owner puts down the facts this is just another, typical of today, grumble where you put a tenth of the story down and gain sympathy from a thousand pseudonyms. Seatbelt worn or not is the remainder nine tenths of this episode.

When you bail out of an aircraft at 3000 feet you wear a parachute. When you drive a car in the country with the world's highest accident rate you wear a seatbelt.

[samaspire]

From the initial photo, it looks like the A pillar took the brunt of the impact first and then the bumper hit the wheels. By then the impact speed would have reduced to less than the threshold for Airbag deployment.

Originally Posted by VaidhiR

2. Occupant detected, but no seatbelt worn.

Is this true for all cars? Even for older generation systems?

Originally Posted by V.Narayan

If you are not wearing seat belts the air bags will not deploy - rule 1.01.

Not so sure about this one. There have been debates here regarding this point. I assume VaidhiR can provide us with the definitive answer.

[V.Narayan]

I am no automotive expert but whatever I have read indicates that Air bags will not deploy if the seat belt is not fastened. The velocity with which an airbag deploys can cause severe damage to face and chest if the person is not restrained back by the seatbelt. Just my two paisa worth. Look forward to the inputs from the experts.

Originally Posted by samaspire

Not so sure about this one. There have been debates here regarding this point. I assume VaidhiR can provide us with the definitive answer.

[aadya]

Originally Posted by V.Narayan

I am no automotive expert but whatever I have read indicates that Air bags will not deploy if the seat belt is not fastened. The velocity with which an airbag deploys can cause severe damage to face and chest if the person is not restrained back by the seatbelt. Just my two paisa worth. Look forward to the inputs from the experts.

I second this. Key point of discussion is whether 1.Driver was wearing the seat belt at the time of impact 2.Impact on the Crumble zone was forcible enough to trigger the sensor.

By definition Airbag is an SRS - Supplementary Restraint System. Primary restraint system is Seat belt only.

[Nonstop-driver]

Originally Posted by V.Narayan

I am no automotive expert but whatever I have read indicates that Air bags will not deploy if the seat belt is not fastened. The velocity with which an airbag deploys can cause severe damage to face and chest if the person is not restrained back by the seatbelt. Just my two paisa worth. Look forward to the inputs from the experts.

Is this true for all cars? AFAIK, my car's manual "recommends" wearing seat belt because airbags explosion can cause damage but nowhere it says that airbag deployment is contingent to seatbelt being in place.