G900X/G950 Installation and Maintenance Manual – GCU 476
Page 9-1
190-00719-00
Revision D
9
GCU 476 (Optional)
9.1 Equipment
Description
The GCU 476 refers to the Garmin Flight Management System (FMS) Controller used in the
G900X/G950 Integrated Cockpit System. The GCU 476 provides alphanumeric, softkey, and flight
planning function keys used to interface with the G900X/G950. In addition to alphanumeric, softkey, and
flight planning function keys the GCU 476 provides COM/NAV tuning capabilities. The GCU 476
mounts flush to the aircraft instrument panel using a jackscrew.
9.1.1 Interface
Summary
The GCU 476 interfaces with the GDU 1040 PFD/MFD via RS-232 digital interface.