Cessna SkyHawk SP 172S NAV III 2005 Pilot Operating Handbook page 350

CESSNA
MODEL 172S NAV III
SECTION 9 - SUPPLEMENTS
SUPPLEMENT 3
EMERGENCY PROCEDURES
(Continued)
• When the mode annunciator starts to flash, the
autopilot has changed to a default mode of
operation: ROL for lateral control and/or VS for
vertical control. The autopilot may be engaged in
the previous mode again as soon as the correct
navigation, glideslope or heading signal or source is
available.
•
The HOG annunciation will flash for 5 seconds on
the selection of NAV, APR or REV mode to tell the
pilot to set the HOG bug (HSl) to the desired
course.
(Continued Next Page)
Failure of DC Tum Coordinator - Autopilot will disengage or
will not engage.
Failure of HSI - If HSI fails to function correctly, no heading
signal will be available, so the autopilot HOG, NAV, APR
and REV modes will not function correctly. Only ROL mode
will function correctly.
Failure of the Transponder Pressure Altitude Encoder - The
Altitude Alert and Altitude Preselect functions will not oper-
ate correctly (gray code signal not available).
Failure of the No.2 GIA 63 Integrated Avionics Unit: If the
No.2 GIA 63 unit fails, the autopilot will function only in
ROLmode.
Failure of the GMA 1347 Audio Panel - No aural annunciator
(Electronic sound or tone) will be heard when the autopilot
disengages.
2.
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3.
4.
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5.
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6.
7.
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Effects of equipment failure on autopilot operation:
r'
1. Failure of Attitude Indicator - No effect on autopilot.
Failure of AHRS - The autopilot will function only in ROL
mode.
FAA APPROVED
172SPHAUS-S3-00
U.S. S3-21