System Maintenance Manual

Page 2-2 G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air
Revision F 190-00682-01
2.1.2 GMA 1347D Audio Panel (2)
The Garmin GMA 1347D Audio Panel integrates NAV/COM digital audio, intercom system and marker
beacon controls. The C90 installation includes two GMA 1347 panels. The GMA 1347D panels provide
control of all cockpit intercom/mic systems as well as NAV/COM/ILS audio. The units also provide display
reversion mode control through a large red button. Power to the audio panels is provided by the avionics
bus. These units only power up when the avionics master switch is turned on. The GMA 1347D units
interface with the existing marker beacon antenna, as well as existing mic and phone jacks and oxygen mask
mic.
2.1.3 GMC 710 AFCS Control Unit
The dedicated AFCS controls on the GMC 710 allow crew control interface with the various GFC 700
autopilot / flight director functions. GMC 710 controls are discussed in detail in the G1000/King Air
C90A/C90GT/C90GTi Cockpit Reference Guide. The GMC 710 is powered by the triple fed bus.
2.1.4 GCU 475 FMS Control Unit
The GCU 475 functions as the primary control interface to the GDU 1500 MFD. The GCU 475 provides
alphanumeric, softkey, and flight planning function keys used to interface with the G1000; the MFD does not
possess any knobs or controls other than softkeys. The GCU 475 is powered by the triple-fed bus. Detailed
instructions regarding the controls are discussed in the G1000 Cockpit Reference Guide.