Calibration Procedure E: Magnetometer Interference Test - Garmin GSU 75 Series Installation Manual

5.8 Calibration Procedure E: Magnetometer Interference Test

NOTE
Calibration Procedure E is 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 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. This
procedure validates that no electronic device is interfering with the operation of the
GMU 44 magnetometer which directly impacts the determination of attitude and heading
by the GSU 75 AHRS. Calibration Procedures A-1 through D are not required prior to
this execution of this procedure.
NOTE
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.
1. Initiate the AHRS magnetometer interference test procedure by performing the following steps:
a) If the PFD is not displaying the GSU/GMU CALIBRATION configuration page, follow
steps from calibration procedure A-1.
b) The FMS small knob can now be used to select which calibration/validation procedure to
run. Select MAG INTERFERENCE TEST and press the ENTER key. If the MAG
INTERFERENCE TEST selection is still blinking, press the ENTER key again.
c) Follow the checklist items displayed on the PFD, and press the ENTER key as each one is
completed or confirmed.
NOTE
The third item on the checklist instructs the operator to prepare a detailed test sequence
list with precise start and stop times for exercising all electronic devices. Only the
electronic devices that are likely to affect the operation of the GMU 44 magnetometer
need be included in the test sequence. The list of relevant electronic devices varies from
aircraft to aircraft. An example of an appropriate test sequence for both a fixed-wing
aircraft and a helicopter is given in
190-01639-00
Rev. 6
The document reference is online, please check the correspondence between the online documentation and the printed version.
Table 5-2 and Table 5-3.
GSU 75 ADAHRS Installation Manual
Page 5-10
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