Garmin GMA 340 - Intercom System Overview; Intercom Volume and Squelch Control

• PILOT mode isolates the pilot from everyone else and dedicates the aircraft radios
to the pilot exclusively. The copilot and passengers share communication between
themselves but cannot communicate with the pilot or hear the aircraft radios.
• CREW mode places the pilot and copilot on a common ICS communication chan-
nel with the aircraft radios. The passengers are on their own intercom channel and
can communicate with each other, but cannot communicate with the crew or hear
the aircraft radios.
• ALL mode allows full intercom communication between everyone plugged in to
the GMA 340. Aircraft radios are also heard by all.
• MUSIC1 and MUSIC2 stereo entertainment inputs are affected by the intercom
mode selected.
The following table summarizes the ICS operation for the different modes supported by the
GMA 340.
MUSIC1 is normally muted during ICS activity. However an installation option is available to
disable ICS MUTE. Then muting of MUSIC1 will not occur due to ICS activity. A panel mounted
switch may be installed for this function. The MUSIC1 mute trip level is adjustable by the installa-
tion agency.
MODE
PILOT
(LED
LIT)
CREW
(LED
LIT)
ALL
(LEDs
OFF)
PILOT HEARS
Selected Radios.
Pilot.
Selected Radios.
Pilot. Copilot.
MUSIC1.
Selected Radios.
Pilot.
Copilot.
Passengers.
MUSIC1.
COPILOT HEARS
Copilot.
Passengers.
MUSIC1.
Selected Radios.
Copilot. Pilot.
MUSIC1.
Selected Radios.
Pilot.
Copilot.
Passengers.
MUSIC1.
PASSENGER HEARS
Passengers.
Copilot.
MUSIC1.
Passengers.
MUSIC2.
Selected Radios.
Pilot.
Copilot.
Passengers.
MUSIC1.
MUSIC1 MUTING
TRIGGERED BY
Copilot or passenger
intercom activity.
Aircraft radio activity.
MKR activity.
Pilot or copilot activity.
Aircraft radio activity.
MKR activity.
Intercom activity.
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