Garmin GFC 600H Pilot's Manual page 49

3) GMC 605H: Press the APR key.
VOR (VAPP) APPROACH MODE
VOR Approach mode (VAPP) provides greater sensitivity for signal tracking than VOR
Navigation mode.
Selecting VOR Approach Mode:
1) EXTERNAL NAVIGATOR: Ensure a valid VOR frequency is tuned
2) NAVIGATION INDICATOR: Ensure that VOR is the selected navigation
source, the appropriate course is set, and a valid CDI is displayed on the
HSI. If CDI indication is more than 1/2 scale ensure the heading bug is set
as desired.
3) GMC 605H: Press the APR key.
LOCALIZER (LOC) APPROACH MODE
LOC Approach mode allows the Helicopter Flight Control System to fly an ILS
approach with a glideslope. When LOC Approach mode is armed, Glideslope mode
is also armed automatically. LOC captures are inhibited if the difference between
rotorcraft heading and localizer course exceeds 105°.
Selecting LOC Approach Mode:
1) EXTERNAL NAVIGATOR: Ensure a valid localizer frequency is tuned.
2) NAVIGATION INDICATOR: Ensure that LOC is the selected navigation
source, the appropriate course is set, and a valid CDI is displayed on the
HSI.
3) GMC 605H: Press the APR key.
If Approach mode is active and any of the following occur, the HFCS reverts the
lateral axis to ATT:
• Different VHF Nav frequency tuned while in VOR or LOC Approach mode (note
that in some installations Approach mode may remain engaged if there is still
valid deviation after the frequency changes from VOR to VOR, or from LOC to LOC)
• Navigation source switched (e.g. GPS to VOR/LOC, or VOR to LOC)
• Loss of navigation signal
190-02081-04 Rev. A Garmin GFC 600H Pilot's Guide
HFCS
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