Magnetic Compass Check - Garmin GPS 400W, GNC 420W Installation Manual

5.5.6.11.1 Main OBI Output
If the Main OBI output from the GNS 400W Series unit is connected to an RMI navigation indicator
verify the interface as follows:
1. Apply power to the equipment and wait for the GNS 400W Series unit to acquire a position.
2. In the GNS 400W Series unit, set a course to a destination waypoint and ensure GPS is selected
for display on the CDI.
3. If installed, set the RMI select switch to the GPS position.
4. Verify that the RMI needle swings and points towards the GPS waypoint selected.
5. If the Main OBI Output is configured to "Track CDI," ensure that a valid VOR station is not
tuned. Select VLOC on the CDI and verify that the RMI needle is parked at the invalid position.
6. If the Main OBI Output is configured to output "Always GPS," select VLOC on the CDI and
verify that the RMI needle still points towards the GPS waypoint selected.
5.5.6.11.2 VOR OBI Output (GNS 430W Only)
If the VOR OBI output from the GNS 430W is connected to an RMI navigation indicator verify the
interface as follows:
1. Apply power to the equipment.
2. If installed, set the RMI select switch to the VLOC position.
3. Tune a local VOR station, or use a simulated signal from an approved VOR Test System.
4. Verify that the RMI needle swings and points towards the VOR station.
5.5.6.12 DME Tuning Check (GNS 430W Only)
If the GNS 430W is set up to remotely channel a DME, verify the interface as follows:
1. Select a VOR/ILS channel that corresponds to (1) a DME station within a 40 nautical mile range,
or (2) the frequency of a DME ground tester.
2. Verify that the DME locks on to the signal and a valid distance, ground speed and time are
displayed.
3. Tune an invalid VOR station. Verify that the DME changes to an invalid station.
5.5.7

Magnetic Compass Check

Compass swing should be carried out at completion of installation in accordance with AC 43.13-1B,
chapter 12, section 3, paragraph 12-37.
Page 5-36
Rev. E
400W Series Installation Manual
190-00356-02