Garmin GNS 430 - Manual (Page 94)

86
PROCEDURES
ILS Approach
Example
5
ILS Approaches
Precision approaches can be performed with the GNS 430’s built-in VLOC (VOR/
localizer/glideslope) receivers. The GPS receiver can be used for guidance prior to reach-
ing the fi nal approach fi x, but once there, the proper frequency must be selected on the
VLOC window (left side of screen) and the CDI output set to “VLOC”.
The GNS 430 can be set to automatically switch the external CDI output from GPS to
VLOC as you intercept the fi nal approach course. When the ILS approach is activated,
the GNS 430 will automatically switch within 1.2 nautical miles left or right of the fi nal
approach course. This switch can take place anywhere from 2.0 to 15.0 nautical miles
from the FAF.
The illustration at left shows multiple locations along the approach path and which
CDI selection you can expect: GPS or VLOC. Within the area of the shaded box, the
automatic switch from GPS to VLOC should occur.
The automatic switch from GPS to VLOC is not immediate, but instead occurs gradu-
ally to prevent abrupt CDI changes when coupled to an autopilot. The CDI selection
can also be changed manually by pressing the
C key. Once the switch from GPS to
VLOC has occurred, either automatically or manually, it will not automatically switch
again until the approach is reactivated or another approach is selected. To prevent auto-
matic ILS CDI selection, choose the “Manual” ILS CDI setting, as described on page
155. (The factory default setting is “Auto”, which enables the automatic switch to VLOC.)
NOTE
If you attempt to intercept the approach course at a distance less than 2.0 nau-
tical miles from the FAF, the GNS 430 will not automatically switch the CDI to
VLOC. In this case, press the CDI key to manually switch from GPS to VLOC.
2 NM
15 NM
1.2 NM 1.2 NM
MANUAL
FAF
VLOC
VLOC
GPS
GPS
Auto Switch
to VLOC
within this area
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