When should an
air
bag inflate?
The air bag is designed to inflate in moderate to severe
frontal or near-frontal crashes. 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
kmh).
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.
Thc
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
the vehicle’s deceleration. Vehicle damage is only one
indication
of
this.
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
the
air bag. The inflator, air bag, and
related hardware are all part of
the
air bag modules
packed inside the steering wheel and in the instrument
panel
in
front of the right front passenger.
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