Buick PARKAVENUE 1994 Manual page 40

In any particular crash, the determination of whether the
air bag should have inflated cannot be based solely on
the level of damage on the vehicle(s). Inflation is
determined by the angle of the impact and the vehicle's
deceleration, of which vehicle damage is only one
indication. Repair cost is not a good indicator of
whether an air bag should have deployed.
What makes an air bag inflate?
In
a
frontal or near-frontal impact of sufficient severity,
the air bag sensing system detects that the vehicle is
suddenly stopping as a result of a crash. The sensing
system triggers a chemical reaction of the sodium azide
sealed in the inflator. The reaction produces nitrogen
gas, which inflates a cloth bag. The inflator,
cloth
bag,
and related hardware are all part of the air bag inflator
modules packed inside the steering wheel and in the
instrument panel in front of the passenger.
how does an air bag restrain?
In moderate to severe frontal or near-frontal collisions,
even belted occupants can contact the steering wheel or
the instrument panel. The air bag supplements the
protection provided by safety belts. Air bags distribute
the force of the impact more evenly over the occupant's
upper body, stopping the occupant more gradually. But
air bags would not provide protection in many types of
collisions, including rollovers and rear and side impacts,
primarily because an occupant's motion is not toward
the air bag. Air bags should never be regarded as
anything more than a supplement to safety belt
protection in moderate to severe frontal and near-frontal
collisions.
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