Honda 2001 Passport, Owner'S Manual, Page: 303 / 317

When sensors detect a severe frontal
collision, the airbags instantly inflate
to provide extra protection for an
occupant's head and chest.
After inflating, the airbags immediately
deflate. The entire process of inflation,
protection, and deflation takes place in a
fraction of a second—so fast that many
people involved in accidents say they did not
realize their airbag had deployed until they
saw the deflated bag lying in front of them.
The fact that an airbag can automatically
help protect you is quite remarkable, yet the
underlying principle is quite simple.
When an airbag equipped car is involved
in a severe frontal collision, sensors detect the
crash and instantly inflate the airbags. While
your seat belt restrains your torso, the airbag
provides a cushion for your chest and head,
which cannot be fully restrained by a seat
belt.