Nobody ever wants to experience an automobile airbag deploying. However, everyone is glad they appear in milliseconds when needed. Airbags have saved thousands of lives and prevented thousands of serious injuries since the late 1980s. How does an airbag know to save your life?
Airbag systems have three components: sensors, inflators and the bags themselves. Sensors at various key points in a vehicle determine whether a crash is underway. Sudden braking, wheel speed, occupant status, pressure as an impact occurs, and more indicate a crash. Information travels from sensors to a monitoring unit that evaluates each situation and triggers a response, which can include airbag deployment, as well as seat belt and door locking. The force required to cause an airbag deployment varies based on the type and location of the bag, the type of impact, and other factors, but it is roughly the equivalent of hitting a brick wall at 10-15 mph.
A Controlled Explosion
When the monitoring system determines the need for airbag deployment, it sends a signal to one or more inflators to initiate the chemical reaction that fills the bag(s) primarily with nitrogen gas. This “controlled explosion” fully inflates the bag in a fraction of a second. Depending on the vehicle, there can airbags hidden behind panels in a number of places including the steering wheel column, dashboard and doors.
Gone in a flash
Immediately after it reaches full inflation, an airbag begins to deflate through small vent holes in its thin nylon fabric. This allows occupants to exit the vehicle and gives emergency responders better access to passengers if needed.
Reactions and Risks
The lightning fast reaction of an airbag is required to help prevent injury. However, airbag systems are not foolproof. There have been instances of deployment without a collision or even with excessive force which have caused injuries to passengers. Consequently, you should check your vehicle’s manual for more specifics on these general safety tips:
• If an airbag system warning light illuminates on your instrument panel, immediately have the car checked by a qualified technician.
• Always wear your seat belt. Airbags are not meant to be a replacement for them.
• Sit as far back from the steering wheel and dashboard as is possible and practical. This gives the airbag extra time and space in which to deploy.
• Always have children age 12 or younger sit in the back seat with a seat belt on.
• Read your owner’s manual to understand options for turning off passenger airbags if needed.
The most effective airbags never have to be deployed. Safe and defensive driving is key.