By Eliza Geh
Airbags
Certified Flight Instructor
Airbags
An airbags purpose is to aid the passengers in the car to reduce their speed in a collision and decrease the possibility of getting injured. Every object has momentum, which is the product of a passenger’s mass and velocity. To stop the passengers momentum in a vehicle the person has to be acted on by a force. The more time the force of an airbag has to act on the passenger to slow them down, the less damage caused to the passenger. There is approximately 15 to 20 milliseconds after the collision occurs when the crash sensors evaluate the seriousness of the collision and whether to inflate the airbag. The airbag will be deflated approximately 25 milliseconds after the crash.
How They Work
There are three parts of the airbag that help to accomplish slowing the passenger’s forward motion as evenly as possible in the shortest possible time. The bag is made of a thin, nylon fabric, which is located inside the steering wheel or dashboard and up until recently, the seat or door. The sensor is the device that instructs the bag to inflate. Inflation will occur when there is a collision force equal to crashing into a brick wall at 16 to 24kmph. The final part is the airbag's inflation system, which reacts sodium azide with potassium nitrate to produce nitrogen gas. Hot blasts of the nitrogen gas inflate the airbag.
Side Airbags
Side airbags are located in the back-rest of the seat and inflate between the door and the occupant. They reduce serious chest injuries in a side-impact collision by approximately 25%. The benefits of having an airbag that is located in the back-rest is that it will move with the seat and provide optimal protection for the occupants.
Pelvis-Thorax Airbags
These are designed to reduce the risk of injury to the thorax and pelvic regions. This takes advantage of the pelvis’s ability to take higher loads while limiting pressure on the sensitive thorax/abdomen area.
Curtain Airbags
Curtain airbags deploy instantly from the top of the door rails above the side window. These airbags form a cushion between the occupants and the window and remain in place if the car were to roll over to protect their head. Research conducted in the USA states that curtain airbags reduce driver deaths in a side impact crash by an estimate of 40%.
