SECTION 9 - SUPPLEMENTS
CESSNA
SUPPLEMENT 3
MODEL 172S NAV III
GENERAL
(Continued)
A locking device prevents the autopilot or MET from engaging until
the autopilot computer has completed the preflight self-test
sequence and finds that the system is not defective. The preflight
self-test starts when the AVIONICS BUS 2 Switch is set to the ON
position.
The KAP 140 Autopilot will disengage if any of the following
conditions occur:
1. Internal Autopilot System malfunction.
2. Autopilot Computer Monitor detects either R (roll axis) or P
(pitch axis) malfunction annunciation.
3. Pitch accelerations larger than + 1.4g or - 0.6g caused by
a servo malfunction. The pilot cannot maneuver the
airplane and cause the autopilot to disengage, although
some turbulence can.
4. DC Electric Turn Coordinator malfunction.
5. The A/P DISC/TRIM INT Switch on the LH Control Wheel is
pushed.
The AVIONICS BUS 2 Switch supplies electrical power to the
AUTO PILOT Circuit Breaker from AVN BUS 2. The AVIONICS
BUS 2 Switch can also de-energize the Autopilot or MET system in
an emergency.
(Continued Next Page)
FAA APPROVED
S3-6 U.S.
172SPHAUS-S3-00