GNC 420(A) Pilot’s Guide and Reference
2-5
SECTION 2
COM
190-00140-20 Rev. K
Selecting a COM frequency for any airport
in the database:
1) Turn the large
right
knob to select the WPT
Page Group.
2) Turn the small
right
knob to select the Airport
Frequencies Page (Figure 2-9).
Figure 2-9 Airport Frequencies Page
3) Press the small
right
knob to place the cursor
on the airport identifier field.
4) Use the small and large
right
knobs to enter
the identifier of the desired airport. Press the
ENT
Key when finished.
5) Turn the large
right
knob to highlight the
desired frequency.
6) Press the
ENT
Key to place the highlighted
frequency in the standby COM Window field.
Emergency Channel
The GNC 420’s emergency channel select provides
a quick method of selecting 121.500 MHz as the
active frequency in the event of an in-flight emergency.
Emergency channel select is available anytime the unit
is on, regardless of GPS or cursor status, or loss of the
display.
To quickly tune and activate 121.500:
Press and hold
COM Flip-flop
Key (or COM
Remote Tranfer Switch) for approximately two
seconds (Figure 2-10).
Figure 2-10 Emergency Channel Active
If the COM Remote Transfer switch is used to select the
emergency channel, further changes in COM frequency
will not be possible without momentarily pressing the
COM Remote Tranfer Switch again, or by recycling
power.
NOTe: Under some circumstances if the COM
system loses communication with the main
system, the radio will automatically tune to
121.500 MHz for transmit and receive, regardless
of the displayed frequency.
Summary of Contents for GNC 420
Page 1: ...GNC 420 A Pilot s Guide and Reference ...
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Page 62: ...GNC 420 A Pilot s Guide and Reference SECTION 3 NAV PAGES 3 28 Blank Page 190 00140 20 Rev K ...
Page 134: ...GNC 420 A Pilot s Guide and Reference 7 24 SECTION 7 WPT PAGES Blank Page 190 00140 20 Rev K ...
Page 148: ...GNC 420 A Pilot s Guide and Reference 8 14 SECTION 8 NRST PAGES Blank Page 190 00140 20 Rev K ...
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