Air Bags
inflate very quickly in the event of a severe frontal crash.
They are designed to work together with the seat belt and do not
eliminate the need for a seat belt (The SRS in "SRS Air Bag"
stands for Supplementary Restraint System). The inflated air bag
cushions the head, of the occupant and prevents the occupant hitting
the dash, steering wheel or windscreen.
A typical
air bag starts to inflate within about 2 one-hundreths of a second
of the start of the crash and is fully inflated some 3 one-hundredths
of a second later. The occupant is thrown forward into the air
bag at about this time and starts to sink deeply into the air
bag. After about one-tenth of a second the air bag begins to deflate,
having served its purpose.
Full-width
frontal crash tests conducted by the Federal Office of Road Safety
and
Australian NCAP compared the protection from serious head
injury provided by driver's air bags. The results are set out
in the brochure Air Bags Enhance Safety. The Holden Commodore,
Mitsubishi Magna and Toyota Camry were tested with and without
a driver's air bag. For the Commodore and Camry without an air
bag the risk of serious head injury was about double that of the
same model with a driver's air bag. The Magna was the best performer
of vehicles without an air bag but the risk of serious head injury
was four times that of the vehicle with an air bag.
For further
information on
Australian NCAP test procedures please read the following
research papers written by Australian safety engineer Michael
Paine: 1.
Consumer Crash Tests: The Elusive Best Practice | 2.
Offset Crash Tests | 3.
Guidelines for Crashworthiness Rating Systems
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