Ford 2009 Mountaineer Owner's Manual page 627

The Safety Canopy system, in combination with safety belts, can help
reduce the risk of severe injuries in the event of a significant side impact
collision or rollover event.
Children 12 years old and under should always be properly restrained in
the second or third row seats (if equipped). The Safety Canopy will not
interfere with children restrained using a properly installed child or
booster seat because it is designed to inflate downward from the
headliner above the doors along the side window openings.
The Safety Canopy system is designed to activate when the vehicle
sustains lateral deceleration sufficient to cause the side crash sensor to
close an electrical circuit that initiates Safety Canopy inflation or when
a certain likelihood of a rollover event is detected by the rollover sensor.
The Safety Canopy is mounted to the roof side-rail sheet metal, behind
the headliner, above the first and second row seats. In certain lateral
collisions or rollover events, the Safety Canopy system will be activated,
regardless of which seats are occupied. The Safety Canopy is designed
to inflate between the side window area and occupants to further
enhance protection provided in side impact collisions and rollover events.
The fact that the Safety Canopy system did not activate in a collision
does not mean that something is wrong with the system. Rather, it
means the forces were not of the type sufficient to cause activation. The
Safety Canopy is designed to inflate in certain side impact collisions or
rollover events, not in rear impact, frontal or near-frontal collisions,
unless the collision causes sufficient lateral deceleration or rollover
likelihood.
WARNING: Several Safety Canopy system components get hot
after inflation. Do not touch them after inflation.
2009 Mountaineer (mnt)
Owners Guide, 2nd Printing
USA (fus)
Seating and Safety Restraints
203