Cessna 172R, Operating Handbook

Page: 442 / 500

SECTION
9
-
SUPPLEMENTS
SUPPLEMENT
15
-
FAA
APPROVED
CESSNA
MODEL 172R
AMPLIFIED EMERGENCY PROCEDURES
The
following paragraphs are presented
to
supply additional
information for the
purpose
of providing the pilot with a more
complete understanding of the recommended course
of
action
for~
an emergency
situation.
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, and especially for autopilot trim, there may be little
to
no airplane motion,
yet
the red
PITCH
TRIM annunciator
(airplane’s annunciator panel) may illuminate and
an alert
tone
may sound.
The primary
concern in reacting
to
an autopilot or autopilot
trim malfunction, or
to
an automatic disconnect
of the
autopilot, is in maintaining control
of the airplane.
Immediately
grasp the control wheel and press and hold down the A/P
DISC/TRIM INT switch throughout the recovery. Manipulate
the controls as required
to safely
maintain operation of the
airplane within all of its operating limitations. Elevator trim
should be used manually
as needed
to
relieve control forces.
Locate and pull the AUTO PILOT circuit breaker on the
right hand circuit breaker panel
to
completely disable the
autopilot
system.
2.
A manual electric trim malfunction
may be
recognized by
illumination of the
red PITCH TRIM annunciator, accompanied
by an alert
tone,
or by unusual trim wheel motions with the
autopilot OFF, without pilot actuation of the manual electric
trim switches. As
with
an
autopilot malfunction, the first
concern following a manual electric trim malfunction is
maintaining control of the airplane. Grasp the control wheel
firmly and
press and hold down the A/P DISC/TRIM INT
switch. Locate
and pull the
AUTO PILOT
circuit breaker
on
the right hand breaker panel.
S15-16
Original
Issue