Line Replaceable Units - Garmin G900X Pilot's Manual

SYSTEM OVERVIEW

1.1 LINE REPLACEABLE UNITS

• GDU 1040/1045 (2 or 3) – In a two display configuration, the left-hand GDU is configured as a Primary Flight
Display (PFD) and the right-hand GDU as a Multi Function Display (MFD). In a three display configuration, the
left and right GDUs are configured as Primary Flight Displays (PFDs) and the middle GDU as a Multi Function
Display (MFD).All feature 10.4-inch LCD screens with 1024 x 768 resolution. The displays communicate with
each other through a High-Speed Data Bus (HSDB) Ethernet connection. Each display is also paired with an
Ethernet connection to an IAU.
• GMA 1347 – The Audio Panel integrates navigation/communication radio (NAV/COM) digital audio, intercom,
and marker beacon controls, and is installed between the displays. This unit also provides manual control of
display reversionary mode (red DISPLAY BACKUP Button; see Section 1.5, System Operation) and communicates
with both IAUs using an RS-232 digital interface.
• GIA 63W (2) – The Integrated Avionics Units (IAU) function as the main communication hubs, linking all
LRUs with the on-side display. Each IAU contains a GPS SBAS receiver, VHF COM/NAV/GS receivers, and
system integration microprocessors, and is paired with the on-side display via HSDB connection. The IAUs are
not paired together and do not communicate with each other directly.
• GDC 74A (1 or 2) – The Air Data Computer (ADC) processes data from the pitot/static system and outside air
temperature (OAT) sensor. The ADC provides pressure altitude, airspeed, vertical speed, and OAT information
to the system. It communicates with the primary IAU, displays, and AHRS using an ARINC 429 digital interface.
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Garmin G900X Pilot's Guide 190-00726-00 Rev. J