Garmin G300 Installation Manual page 76

9.3.6 Calibration Procedure F: Magnetometer Interference Test
Calibration 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. 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 GRS 77 AHRS. Calibration Procedures A through D are not required prior to this
execution of this procedure.
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.
1. Enter configuration mode by holding down the left-hand softkey while powering on the
GDU 37X (if needed).
2. Use the FMS Joystick to select the GSU Page (if needed).
3. Unlock GSU Page by pressing softkeys 2, 3, 4 in order (if needed).
4. Ensure that all three status boxes indicate a positive state (green check marks). The GMU 44
and GSU 73 units must be communicating with the GDU 37X, and the GPS antenna must
have clear view of the sky or a GPS repeater to produce positive status indications.
Page 9-20
Revision A
NOTE
NOTE
G300 Installation Manual – Post Installation Checkout and Calibration Procedures
190-00921-01