Mistry’s death shows the importance of airbags. But they are pointless without seat belts

Many would consider Cyrus Mistry’s Mercedes-Benz GLC 220d ‘safer’. But there were several bad hot-takes on social media about the car's ‘rear’ airbags not getting deployed.

Safety belt in a car | Representational image | Flickr

First and foremost, deepest condolences to the Mistry and Pandole families for the fatal accident that occurred on Sunday. It was a reminder that traffic accidents can impact the rich and the poor just as hard. According to the latest National Crime Records Bureau report on accidental deaths, 155,622 people died on Indian roads in 2021 with Uttar Pradesh, unsurprisingly due to its size, recording the highest number of deaths at 24,711.

But Cyrus Mistry’s accident is another reminder that it doesn’t matter which vehicle you are driving, accidents can be fatal regardless. According to data from the Ministry of Road Transport and Highways’ Vahan portal, Mistry’s vehicle was a 2018 Mercedes-Benz GLC 220d, a car many would consider much ‘safer’ given its luxury pedigree. This led to several bad hot-takes on social media blaming the vehicle for the ‘rear’ airbags not getting deployed.

Much like air accidents, it is wrong to speculate about what ultimately caused this accident. But it is important to lay down some facts regarding vehicular safety. Starting with airbags. Cars don’t really have ‘rear airbags’ in the same sense that they have front driver and passenger airbags. The latest cars with six airbags, for example Maruti-Suzuki Brezza, have the following: two airbags for a frontal impact for the driver and the passenger at the front; two airbags inside the front seats (which is why you must not use any old aftermarket seat cover anymore) for side impacts, or like in the GLC involved in the crash, knee airbags; and two airbags, usually located on the B-pillar (between the front and rear doors) that deploys if the pillars get warped and the glass shatters to protect occupants from flying glass shards. The last set of airbags would have been useful for me 15 years ago when I had my first major accident.

The misconception that there is a ‘rear airbag’ fitted to the front seat or headrest to protect the rear passenger is an oddly prevalent one. Although, some of the latest vehicles in some markets do have a neck-cushion airbag to mitigate whiplash injuries. Also, some cars are now installing seat-belt airbags, similar to those found on some business-class seats on long-haul aircraft. And there are often separate curtain airbags for the rear window instead of one giant airbag covering the front and rear window panes. And Mercedes-Benz has now actually fitted such airbags on the latest W223 version of the S-Class luxury sedan. But the S-Class has an acre of space between the front and rear seats, most cars don’t and that brings me to the reason why ‘rear airbags’ can’t be fitted on cars in the way we would like them to be fitted.

Little humans

Airbags are dangerous for them. Infant carriers or rearward-facing child car seats would be blown up and away in case a headrest mounted airbag deployed. If you have a car with two front airbags, the rear of the passenger sun visor has a warning that says just this. In case you fit a rearward-facing child seat in the front passenger seat, you must disable the front passenger airbag. Also, if you make any child below four foot tall sit in the front seat, you are actively endangering that child.

It is also important to understand how airbags work. It is not a small cylinder of compressed air that sits underneath them, it is a small explosive charge. Now, when explosives blow up, they create a lot of hot air and suck more air in rapidly, which is why airbags inflate in milliseconds. Inflatable slides on aircraft used the same method to inflate rapidly. It is this explosive charge that caused the massive recall of Takata airbags, which impacted some models of Honda cars in India. The Takata airbag explosive degraded with time, as many explosives do, and went off unexpectedly. Airbag explosives have to be very stable for many years of installation, in fact they should be stable for the 15 years you can own a vehicle in India.

But, on some cars, older ones in particular, you see an ‘SRS’ sign above the ‘airbag’ sign, particularly on the front. This is not a brand logo, it stands for ‘Supplemental Restraint System’ and it means what it says. The airbag is a supplementary system to back-up the primary restraint system, which is, and remains, the three-point seatbelt. This invention by Volvo engineer Nils Bohlin has saved countless lives across the world. In its modern ‘pre-tensioned’ avatar, where the belts tighten in case of heavy acceleration or braking, it is safer still.

Airbags, seat belts go hand-in-hand

Airbags are not supposed to deploy if seat belts are not being worn. This is because they can cause serious injury or even prove fatal in such deployments. This is not a failsafe mechanism though. Sometimes people bypass the system by using plugs for their seat belts to switch off the alarm. In addition, one thing is clear about the accident that we are talking about—both victims were seated in the rear. This is a surprisingly common occurrence. From comedian Jaspal Bhatti to Princess Diana, rear seat passengers have been killed in car crashes with a distressingly common thread in all cases—none of them were wearing the seat belt.

None of this is to say that even wearing the seat belt would have saved anyone, in extremely high-speed accidents. Unless you are sitting inside a tub made of carbon-fibre like Formula 1 drivers, your chances of survival are low. Cars are legally required in most countries to be crash-tested at 64 kilometres per hour into a stationary object; the proposed Bharat-NCAP rules will be the same. No car is tested for a triple-digit speed accident, and that could even be two vehicles moving towards each other at a combined speed exceeding a hundred kilometres.

But the fact that the front passengers in the Mistry accident case survived and were wearing seat belts, as per the initial investigation, says a lot. Airbags are not a panacea in accidents, they can help prevent serious injuries and even allow victims to walk away unscathed. But they are pointless without seat belts. The amended Motor Vehicles Act does make it mandatory to wear the seat belt even in the rear seat of a car, but if you are to take away anything from this tragic event, let it be this: Wear your seat belt even while seated at the back.

@kushanmitra is an automotive journalist based in New Delhi. Views are personal.