Air Bag Deactivation: How Air Bags Work



How air bags work

Air bags are designed to keep your head, neck, and chest from slamming into the dash, steering wheel or windshield in a front-end crash. They are not designed to inflate in rear-end or rollover crashes or in most side crashes. Generally, air bags are designed to deploy when the severity of a crash reaches a preset threshold value. Depending on the specific vehicle model, this threshold is normally equivalent to a vehicle crashing into a solid wall at 13-23 km/h. Air bags most often deploy when a vehicle collides with another vehicle or with a solid object like a tree.

Air bags inflate when a sensor detects a front-end crash severe enough to trigger their deployment. The sensor sends an electric signal to start a chemical reaction that inflates the air bag with harmless nitrogen gas. All this happens faster than the blink of an eye. Air bags have vents, so they deflate immediately after absorbing the energy of an occupant. They cannot smother you and they don't restrict your movement. The "smoke" you may have seen in a vehicle after an air bag demonstration is the nontoxic starch or talc that is used to keep the insides of the air bag from sticking together.



Are all air bags the same?

No. Air bags differ in design and performance. There are differences in the crash speeds that trigger air bag deployment, the speed and force of deployment, the size and shape of air bags, and the manner in which they unfold and inflate. Air bag systems are very complex, computer-controlled devices which, if improperly deactivated, could deprive the vehicle occupants of the benefit of other vital safety systems. That is why you should contact your vehicle manufacturer if you want more information about the air bags in your particular car or truck.



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