Chevrolet MONTE CARLO 1998 Manual page 32

If something is between an occupant and an air
bag, the bag might not inflate properly or it
might force the object into that person. The path
of an inflating air bag must be kept clear. Don't
put anything between an occupant and an air
bag, and don't attach or put anything on the
steering wheel hub or on or near any other air
bag covering.
When should an air bag inflate?
An air bag is designed to inflate in a moderate to severe
frontal or near-frontal crash. The air bag will inflate
only if the impact speed is above the system's designed
"threshold level." If your vehicle goes straight into a
wall that doesn't move or deform, the threshold level is
about 9 to 15 mph (14 to 24
km/h).
The threshold level
can vary, however, with specific vehicle design, so that
it can be somewhat above or below this range. If your
vehicle strikes something that will move or deform, such
as a parked car, the threshold level will be higher. The
air bag is not designed to inflate in rollovers, side
impacts or rear impacts, because inflation would not
help the occupant.
In any particular crash, no one can say whether an air
bag should have inflated simply because of the damage
to a vehicle or because of what the repair costs were.
Inflation is determined by the angle of the impact and
how quickly the vehicle slows down in frontal or
near-frontal impacts.
What makes an air bag inflate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. The sensing
system triggers a release of gas from the inflator, which
inflates the air bag. The inflator, air bag and related
hardware are all part of the air bag modules inside the
steering wheel and in the instrument panel in front of the
right front 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. Air bags supplement 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 help you in many types of collisions, including
rollovers, rear impacts and side impacts, primarily
because an occupant's motion is not toward those air
bags. Air bags should never be regarded as anything
more than a supplement to safety belts, and then only in
moderate to severe frontal or near-frontal collisions.