Does the GMA 340 have a Split COM Function?

Yes, pressing the COM 1/2 button activates the split COM function. When this mode is active, COM 1 is dedicated solely to the pilot for MIC/audio, while COM 2 is dedicated to the copilot for MIC/audio. The pilot and copilot can simultaneously transmit in the mode over separate radios. Both pilots can still listen to COM 3, NAV 1, NAV2, DME, ADF, and MKR as selected. The split COM mode is cancelled by pressing the COM 1/2 button a second time.

For more information on the GMA 340, see the Owner's Manual.