190-02177-02 Rev. A
Garmin G1000 NXi Pilot’s Guide for the Cessna NAV III
SY
STEM
O
VER
VIEW
FLIGHT
INSTRUMENTS
EIS
AUDIO P
ANEL
& CNS
FLIGHT
MANA
GEMENT
HAZARD
AV
OID
ANCE
AFCS
ADDITIONAL
FEA
TURES
APPENDICES
INDEX
1
SYSTEM OVERVIEW
SECTION 1 SYSTEM OVERVIEW
1.1 SYSTEM DESCRIPTION
This section provides an overview of the G1000 NXi Integrated Avionics System as installed in the
Cessna
NAV III. The system presents flight instrumentation, position, navigation, communication, and identification
information to the pilot through large-format displays.
LINE REPLACEABLE UNITS (LRU)
The system consists of the following Line Replaceable Units (LRUs):
-
GDU 1054B/1050
(2) – The system features two 10.4-inch backlit LED display units with high resolution.
The left display is configured as a Primary Flight Display (PFD) and the right display is configured as an Multi
Function Display (MFD). The displays communicate with each other through a High-Speed Data Bus (HSDB)
connection. Each display is also connected to the onside Integrated Avionics Unit (IAU). Systems configured
with the Garmin Automatic Flight Control System (AFCS) use the GDU 1054B. Systems without the Garmin
AFCS use the GDU 1050.
-
GIA 63W / GIA 64W
(2) – The GIA Integrated Avionics Units (IAU) function as the main communication
hub, linking all LRUs with the PFD and MFD. Each IAU contains a GPS SBAS receiver, VHF COM/NAV/GS
receivers, a flight director (FD) and system integration microprocessors. Each IAU is paired with the PFD and
MFD via HSDB connection.
-
GSU 75
(1) – The GSU Air Data and Attitude Reference System (ADAHRS) processes data from the pitot/
static system as well as the Outside Air Temperature (OAT) probe to provide pressure altitude, airspeed,
vertical speed and OAT information to the system. This unit also provides aircraft attitude and heading
information via ARINC 429 to the PFD, MFD, and IAU. The ADAHRS contains advanced sensors (including
accelerometers and rate sensors) and interfaces with the Magnetometer to obtain magnetic field information,
and with the IAUs to obtain GPS information. ADAHRS/AHRS modes of operation are discussed later in this
document.
-
GMU 44
(1) – The GMU Magnetometer measures local magnetic field. Data is sent to the ADAHRS for
processing to determine aircraft magnetic heading. The unit receives power directly from the ADAHRS and
communicates with the GRS unit using an RS-485 digital interface.
-
GDC 74A
(1) (Optional) – The GDC Air Data Computer (ADC) processes data from the pitot/static system
as well as the OAT probe. This unit provides pressure altitude, airspeed, vertical speed and OAT information
to the system, and it communicates with the IAUs, the PFD, MFD, and the Attitude and Heading Reference
System (AHRS), using an ARINC 429 digital interface (it also interfaces directly with the Air Temperature
Probe. The unit is designed to operate in Reduced Vertical Separation Minimum (RVSM) airspace.
-
GRS 77
(1) (Optional) – The Attitude and Heading Reference System (AHRS) provides aircraft attitude and
heading information via ARINC 429 to both displays and both IAUs. The unit contains advanced sensors
(including accelerometers and rate sensors) and interfaces with the Magnetometer to obtain magnetic field
information, with the GDC 74A to obtain air data, and with both IAUs to obtain GPS information.
-
GEA 71 / GEA 71B
(1) – The GEA Engine Airframe Unit receives and processes signals from the engine and
airframe sensors. This unit communicates with both IAUs using an RS-485 digital interface.
