Airbags: How They Work, History, Types & More

Written By:

Airbags play a very important role in the modern day safety of passengers in a car. Many know that this is increasingly becoming a standardised safety feature in automobiles throughout the world.

The Supplemental Restraint System (SRS) or Supplemental Inflatable Restraints protects people during an accident, many still have queries as to how do they work.

Lets take a detailed look at how airbags work in an automobile, how they came about, and more.

The story continues in the next slide.

A quick look back:

Airbags date back all the way to 1941. A German engineer named Walter Linderer, and an American industrial engineer named John W. Hetrick, designed the first airbags. Walter, who applied for a patent on October 6, 1951, was granted it in November 12, 1953. About three months prior, Hetrick was issued a patent on August 18, 1953.

Linderer's system was proven to be impractical because it could not inflate fast enough during an accident and Hetrick's design flopped because automobile investors did not invest. When Hetrick's patent finally expired, Ford introduced the airbags as an experiment in a few of their vehicles.

Picture credit: Gopixpic

The actual breakthrough came in when Allen K. Breed introduced mechanical sensors, which could inflate the airbags in 30 milliseconds. The bags were inflated using Sodium Azide instead of compressed air. Breed marketed this innovation with Chrysler. Only during the early 1990s, airbags became widespread in America.

During the 1970s, airbags were offered in passenger vehicles since many did not use seat belts. Ford introduced airbags for a small fleet of vehicles, followed by GM. The early fleet of GM vehicles with airbags recorded 7 fatalities, one in which the airbag was suspected to be the killer.

Later, when road laws became strict regarding safety, seat belts were made mandatory and the usage of airbags decreased for a long time.

Types Of Airbags:

Airbags come in different shapes and sizes to protect almost every part of the human body in a car accident. There are even airbags to protect pedestrians that one may run into!

Frontal Airbag:

The 1987 Porsche 944 Turbo was the first car in the world to come equipped with dual airbags, for the driver as well as the passenger, as a standard fitment. These airbags are mounted on the steering wheel to offer protection for the driver and on the dash, to protect the passenger.

Side Airbag:

Side airbags offer protection to the occupants in case of a side impact. There are two variants. One is a side torso airbag, that is usually located in the seat, that inflates between the driver and the door, to protect the torso.


The second type is the curtain airbag. As the name suggests, the airbag is mounted on the roof and deploys like a curtain to offer protection for the side. Curtain airbags have been said to reduce brain injury or fatalities by up to 45 percent in a side impact with an SUV. Some vehicles offer this airbag which protects all three rows of seats in an impact.

Knee Airbag:

Knee airbags are designed to protect the legs of occupants. It was first used in the 1996 model Kia Sportage vehicle and has been a standard equipment since then. This airbag is usually mounted under the steering wheel. Since they have proved to be very efficient, the knee airbag has become increasingly common since 2000.

Rear Curtain Airbag:

Rear curtain airbags are designed to offer protection to the head for occupants in the back of the car from impacts from the rear. The Toyota IQ featured this airbag in 2008.

Pedestrian Airbag:

First introduced by Volvo in the V40, pedestrian airbags protect unprepared pedestrians in the event of an accident. In a pedestrian test conducted by Euro NCAP, the Volvo scored the highest for pedestrian safety.

Motorcycle Airbag:

Even motorcycles come equipped with airbags to protect riders in a crash. Many have been tested over the years and in 2006, Honda introduced it in its production motorcycle, the Goldwing. Sensors in the fork detect and inflate the airbag in a severe crash.

Airbags In Motorcycle Gear:

There are motorcycle safety gear manufacturers who have been offering airbags in riding suits for MotoGP riders. These kind of suits are now being available to everybody. A small sensor inside the suit detects when an impact is about to happen and immediately inflates inside the suit, offering additional protection to riders.

Major Airbag Makers:

The major airbag makers in the world are Autoliv, Daicel, Takata and TRW.

Takata, the Japanese airbag maker has been in the news recently for a massive recall by carmakers because of faulty airbags made by them.

Operation Of An Airbag:

A central Airbag Control Unit (ACU), monitors many related sensors in the vehicle. Airbags, which are generally hidden away in the steering and under plastic flaps, are designed to rip away inflate when the sensors detect an accident. A gas filled canister discharges gas into the bag which inflate in a matter of milliseconds to cushion the driver.

The gas then slowly escapes the bag through specially designed vents or pores. Once inflated, these life savers will have to be replaced. A replacement will cost, starting at INR 40,000 upwards.

Dangers of an Airbag:

Under rare conditions, airbags can cause injuries to people. Occupants who are not well restrained form the majority of people hurt. One thing that has to be kept in mind is that even though a car is equipped with all the above mentioned airbags, failure to wear a seatbelt will be disastrous.

Airbag Lock For Safety:

Airbags are designed to inflate when there is a collision or near collision. Airbags can inflate when the vehicle's undercarriage strikes an object protruding above the road and decelerating rapidly. Another such incident is many side impact airbags inflate, detecting a vehicles slant, which on an SUV that is taken off the road, could be dangerous. To avoid airbags deploying in such conditions, there is an option to turn off the airbag.

There are algorithms that take into account factors like the weight of the occupant, the seat location, seatbelt use, and even attempt to determine if a baby seat is present to avoid potential injury.


We hope we have thrown some light on the vital safety feature that is the airbag. Airbags save lives, so please make sure your next car is equipped with these. Do feel free to contact us for more information.

Story first published: Tuesday, November 18, 2014, 11:06 [IST]
Please Wait while comments are loading...

Latest Photos