Cessna SkyHawk SP 172S NAV III 2005 Pilot Operating Handbook page 230

SECTION 7
AIRPLANE AND SYSTEMS DESCRIPTION
CESSNA
MODEL 172S NAV III
INTEGRATED SEAT BELT/SHOULDER HARNESS
(Continued)
Proper locking of the lap belt can be verified by ensuring that the
belts are allowed to retract into the retractors and the lap belt is
snug and low on the waist as worn normally during flight. No more
than one additional inch of belt should be able to be pulled out of
the retractor once the lap belt is in place on the occupant. If more
than one additional inch of belt can be pulled out of the retractor,
the occupant is too small for the installed restraint system and the
aircraft should not be occupied until the occupant is properly
restrained.
Removal is accomplished by lifting the release mechanism on the
buckle or by pressing the release button on the buckle and pulling
out and up on the harness. Spring tension on the inertia reel will
automatically stow the harness.
A manually adjustable seat belt/shoulder harness assembly is
available for all seats.
To use the manually adjustable seat belt/shoulder harness, fasten
and adjust the seat belt/shoulder harness first. Lengthen the seat
belt as required by pulling on the release strap on the belt. Snap
the connecting link firmly into the buckle, then adjust to length. A
properly adjusted harness will permit the occupant to lean forward
enough to sit erect, but prevent excessive forward movement and
contact with objects during sudden deceleration. Also, the pilot
must have the freedom to reach all controls easily.
Disconnecting the manually adjustable seat belt/shoulder harness is
accomplished by pushing the button on the buckle to release the
connecting link.
7-24 U.S.
172SPHAUS-OO