Cessna SkyHawk SP 172S NAV III 2005 Pilot Operating Handbook page 373

SECTION 9 - SUPPLEMENTS
SUPPLEMENT 3
NORMAL PROCEDURES
(Continued)
CESSNA
MODEL 172S NAV III
• The autopilot can hold a Vertical Speed selection
only if engine power and airplane weight are
correct for the conditions. If the vertical speed set
for the autopilot is more than the airplane can
supply and airspeed decreases sufficiently, the
airplane can be made to stall. Make sure that the
vertical speed set for the autopilot results in
airplane performance that stays in the operating
limitations of both the autopilot and the airplane.
• When operating at or near the best rate-of-climb
airspeed, with the engine set to climb power or
when in Vertical Speed mode, it can be easy to
slow to airspeeds where any additional reduction
in airspeed will result reduced rate-of-climb. Hold
sufficient airspeed during Vertical Speed mode
operation to avoid a stall.
c. AP Button - PUSH and HOLD to engage the autopilot.
Make sure that ROL and VS are shown on the face of the
autopilot. If no selection of other operating modes is made,
the autopilot will operate in ROL and VS modes.
NOTE
When operating in ROL mode, turbulence may result
in changes to airplane heading. ROL mode only
works to keep the wings level. When tracking the
ILS course outbound on the missed approach
procedure, use NAV mode to prevent unwanted GS
coupling.
BEFORE LANDING
1. AlP DISCITRIM INT Switch - PUSH to disengage the
autopilot.
PERFORMANCE
There is no change in airplane performance when the KAP 140
Autopilot is installed. See Section 2 for Limitations that can have
an effect on airplane performance.
S3-44 U.S.
FAA APPROVED
172SPHAUS-S3-00