CESSNA
SECTION 9 - SUPPLEMENTS
MODEL 172S NAV III
SUPPLEMENT 3
EMERGENCY PROCEDURES
(Continued)
1. An autopilot or autotrim malfunction occurs when there is an
uncommanded deviation in the airplane flight path or when
there is abnormal control wheel or trim wheel motion. In
some cases, (especially for autopilot trim), there may be little
to no airplane motion, but the PITCH TRIM annunciator (RH
side of PDF) may come on.
2. The primary concern in reacting to an autopilot or autopilot
trim system malfunction, or to an automatic disconnect of
the autopilot, is to keep control of the airplane. Immediately
grasp the control wheel and push and hold the A/P
DISC/TRIM INT switch throughout the recovery. Manipulate
the controls as required to safely keep the airplane within all
of its operating limitations. Elevator trim should be used
manually as needed to relieve control forces. Locate and
open (pull) the AUTO PILOT circuit breaker on the lower
right hand corner of the circuit breaker panel to completely
disable the autopilot system.
3. A manual electric trim system malfunction (without pilot
actuation of the manual electric trim switches) may be
recognized by the PITCH TRIM annunciator coming on or by
unusual trim wheel motions with the autopilot not engaged.
As with an autopilot malfunction, the first concern following a
manual electric trim system malfunction is to keep the
airplane in control. Grasp the control wheel firmly and push
and hold down the A/P DISC/TRIM INT switch. Locate and
pull the AUTO PILOT circuit breaker on the lower right hand
corner of the circuit breaker panel (AVN BUS 2).
Trim system voice messages will be provided for the following flight
conditions:
1. "TRIM IN MOTION" - Elevator trim runs for more than 5
seconds, message repeats every 5 seconds.
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FAA APPROVED
172SPHAUS-S3-00
U.S. S3-17
