Page 9-4
G300 Installation Manual – Post Installation Checkout and Calibration Procedures
Revision A
190-00921-01
9.3
GSU 73/GMU 44 Post-Installation Calibration Procedures
After mechanical and electrical installation of the GSU 73 AHRS and GMU 44 magnetometer have been
completed, prior to operation, a set of post-installation calibration procedures must be carried out.
Table 9-1 describes the necessary calibration procedures:
Table 9-1. Post-Installation Calibration Procedure Summary
Calibration
Procedure
Procedure Name
Procedure
Description
Installations Requiring
Procedure
A
AHRS Orientation
Validate GSU 73
Orientation
Procedure A is required for all
installations
B Pitch/Roll
Offset
Compensation
Level Aircraft
Procedure B is required for all
installations
C Magnetometer
Calibration
Compass Rose
Taxi Maneuver
Procedure C is required for all
installations
D Heading
Offset
Compensation
Compass Rose
Alignment with
Magnetic North
Installations in which GMU 44
alignment is not within 0.5° of
aircraft longitudinal axis
E Engine
Run-Up
Vibration Test
Validate vibration
characteristics of
installation
Procedure E is required for all
installations
F Magnetometer
Interference Test
Validate no
magnetic
interference with
GMU 44
Procedure F is required for initial
installation verification.
This test should also be repeated to
verify all subsequent electrical
changes associated with devices
within 10.0 feet of the GMU 44
magnetometer. Such changes
include, but are not limited to, wiring,
shielding or grounding changes to
any light, strobe, beacon or other
electrical device located in the same
wing as a GMU 44 unit. Likewise,
this test should also be repeated to
verify all subsequent changes to
materials within 10.0 feet of the
GMU 44. Such changes include,
but are not limited to, addition,
removal or modification of ferrous or
electrically conductive materials
located in the same wing as a GMU
44 unit.
Garmin recommends this test be
performed at least once every 12
months by all aircraft
manufacturers on a minimum of
one production aircraft for every
airframe type or model equipped
with the G300 system.