Garmin GNC 420(A) Pilot's Manual & Reference page 170

SECTION 9
AUX PAGES
• 'Position/Map Datum' - Configures position
readout information to the desired position
format. The map datum used in the GNC 420
is WGS 84. Note that using a map datum that
does not match the charts can result in significant
differences in position information. When using
the paper charts for reference only, the GNC 420
still provides correct navigation guidance to the
waypoints contained in the database, regardless of
datum differences.
• 'Date/Time' - Provides settings for time format
(local or UTC; 12- or 24-hour) and time offset.
The time offset is used to define current local
time. UTC (also called GMT or Zulu) date
and time are calculated directly from the GPS
satellites' signals and cannot be changed. To use
local time, simply designate the offset by adding
or subtracting the correct number of hours.
9-22
Setup 1 Page: Airspace Alarms
Setting the airspace warning messages or
changing the altitude buffer:
1)
2)
3)
GNC 420(A) Pilot's Guide and Reference
Select 'Airspace Alarms' from the Setup 1 Page
(Figure 9-55), using the steps described at the
beginning of this section.
Figure 9-55 Airspace Alarms Highlighted
Turn the large right knob to highlight the
'On'/'Off' field next to the desired airspace
type. 'Other SUAs' includes alert, caution,
danger, training, and warning areas.
Turn the small right knob to select 'On' or
'Off', as desired (Figure 9-56). Press the ENT
Key to accept the selection.
Figure 9-56 TWR/CTL Zone Alarm Window
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