There is a restricted amount of time that the airbag has to act between when the car hits
the other object and the passenger hits the steering wheel.
- About 15 to 20 milliseconds after the collision occurs the crash sensors decide whether
or not the collison is serious enough to inflate the airbag (usually 6 - 10 km/h).
- If the crash sensors decide to inflate the airbag it will be deflated at about 25 milliseconds
after the crash.
- It takes about 20 milliseconds to inflate the airbag for the person to land into.
- Around 60 milliseconds the person has made contact with the airbag and the airbag now
starts to deflate.
- The passenger continues to be acted on by the airbag as it is in the deflation process which
takes about 35 to 40 milliseconds.
It is still necessary to wear a seatbelt although all automoblies must be equiped with an airbag
because of a few reasons:
1) The crash sensors do not signal for the airbag to inflate unless the vechile is moving atleast
6 km/h. Damage can still occur to the passenger if the collision is of a slower speed. This is were the seatbelt plays an
2) The airbag located in the steering wheel does not help the passenger in a collision where
another car hits them side on.
3) When the car the passenger is in is backing up and collides the its rear end with another
object the airbag does not help.
With today's technology other airbags are being introduced in addition to the steering
wheel airbag and the passenger airbag. Such airbags that are being introduced are side airbags and head airbags.