Cessna 172R, Operating Handbook

Page: 319 / 500

GARMIN Lid.
or
its subsidiaries
c/o
Garmin International
1200 E.
151“
Street, Olathe, KS 66062 USA
AIRPLANE FLIGHT MANUAL SUPPLEMENT
or SUPPLEMENTAL AIRPLANE FLIGHT MANUAL
for
a
Garmin 400W Scries Navigation System
Section 3. EMERGENCY PROCEDURES
3.1 Emergency Procedures
No change.
3.2 Abnormal Procedures
a) If the Garmin
400W
Series unit
GPS navigation information is
not
available, or is invalid, utilize other remaining operational navigation
equipment installed in the airplane
as
appropriate. If the 400W Series unit
loses
GPS
position and reverts to Dead
Reckoning
mode (indicated by
the
annunciation of
“DR”
in the lower left of the display), the moving
map
will continue to be
displayed. Aircraft position will be based upon
the last valid GPS position and estimated by Dead Reckoning methods.
Changes in airspeed or winds aloft
can affect
the estimated position
substantially. Dead Reckoning is only available in Enroulc mode;
Terminal and Approach modes do
not support DR.
b) If a
“Loss
of Integrity” (INTEG) message is displayed during:
*
Enroutc/Tcmtinal:
continue
to navigate using
GPS
equipment and
periodically cross-check the GPS guidance to other approved
means
of navigation.
•
GPS Approach: GPS approaches arc
not authorized under
INTEG
-
Execute
missed approach or revert to alternate
navigation.
c) During a GPS LPV precision approach
or
GPS LNAV/VNAV approach,
the 400W Series unit will downgrade the approach if the Vertical alarm
limits arc exceeded. This will
cause
the vertical guidance
to
(lag as
unavailable. The procedure
may be
continued using the LNAV only
minimums.
d) During a GPS
LP
approach, the 400YV Series may downgrade the
approach prior
to
the Final Approach Fix if
alarm
limits arc
exceeded. If
this occurs, a
message
will be displayed advising the pilot to use LNAV
minimums. If alarm limits arc exceeded after the Final Approach Fix, the
400W Series unit will flag the lateral guidance and generate a system
message
“ABORT
APPROACH loss of navigation". Immediately upon
viewing the message the unit will
revert to
Terminal alarm limits. If the
position integrity is within these limits lateral guidance
will be restored
190-00356-03 Rev. B
Page 1 1 of 16