Garmin GSU 75 Series Installation Manual page 49

Table 5-1 Post-Installation Calibration Procedure Summary
Calibration
Procedure Name
Procedure
E
If removal and replacement of a GSU 75 or GMU 44 unit is required after post-installation calibration has
been completed, the unit mounting racks must not be moved. If the mounting bolts that secure the GSU 75
mounting racks are loosened for any reason, a new post-installation calibration procedure A-1 (or A-2, if
applicable), B and D (plus C if recommended initially) must be carried out before the aircraft can be
returned to service.
Any GMU 44 removal or replacement requires repeating the magnetometer calibration procedure
(Procedure B), and if recommended initially, the heading offset compensation procedure (Procedure C).
Any degaussing of the area near the GMU 44 mounting location requires repeating the magnetometer
calibration procedure (Procedure B), and if recommended initially, the heading offset compensation
procedure (Procedure C).
A repeat of the pitch/roll offset procedure (either Procedure A-1 or A-2) requires a repeat of the
magnetometer calibration procedure (Procedure B), and also (if previously recommended) a repeat of the
heading offset compensation procedure (Procedure C).
The addition, removal or modification of components that are ferrous, or otherwise magnetic, within 10.0
feet of the GMU 44 magnetometer location after the magnetometer interference test or magnetometer
calibration procedure were completed requires a repeat of both procedures.
Furthermore, electrical changes to the installation that affect components within 10.0 feet of the GMU 44
magnetometer after the magnetometer calibration and magnetometer interference procedures were
190-01639-00
Rev. 6
The document reference is online, please check the correspondence between the online documentation and the printed version.
Magnetometer
Interference Test interference with
Procedure
Installations Requiring Procedure
Description
Required for initial installation
certification.
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 near the GMU 44 unit.
Validate no Likewise, this test should also be
magnetic repeated to verify all subsequent
changes to materials within 10.0 feet of
GMU 44 the GMU 44. Such changes include,
but are not limited to, addition, removal
or modification of ferrous or electrically
conductive materials located near the
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 Garmin Integrated
Flight Deck system.
GSU 75 ADAHRS Installation Manual
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