Cessna 172R, Operating Handbook

Page: 444 / 500

SECTION 9
-
SUPPLEMENTS
SUPPLEMENT 15 - FAA APPROVED
CESSNA
MODEL 172R
2. If
annunciation continues, Airplane Control Wheel
--
GRASP
FIRMLY, disengage the autopilot and check for an
out
of
pitch
trim condition. Manually retrim as required.
3.
AUTOPILOT OPERATION
-
CONTINUE if satisfied that the
out
of trim indication was
temporary.
DISCONTINUE if
evidence indicates a failure of the
auto
trim function.
A red P or R on the face of the autopilot
computer.
1 .
A red P is
an
indication that the pitch axis of the autopilot has
been disabled and
cannot
be engaged.
DO
NOT ENGAGE
INTO A ROLL AXIS ONLY SYSTEM.
NOTE
If
the red P lamp was the result
of
some abnormal
accelerations
on
the airplane, the annunciation should
be
extinguished within approximately one minute and
normal
use
of
the autopilot will be reestablished.
2. A
red R is an indication that the roll axis of the autopilot has
been disabled and
cannot
be engaged. The autopilot
cannot
be reengaged.
Flashing mode annunciation in the display of the autopilot
computer.
1.
Flashing HDG
--
Indicates a failed heading. PRESS HDG
button to
terminate flashing. ROL will be displayed.
2.
Flashing NAV, APR or REV
--
Usually an indication
of
a
flagged navigation
source. PRESS the NAV, APR or REV
button
to
terminate flashing. ROL will be displayed. (Select a
valid navigation source.)
NOTE
A flashing NAV, APR or REV annunciation can also be
caused by
a
failed heading
valid input.
S15-18
Original Issue