Garmin GFC 500 Maintenance Manual page 41

9.3.2.5 GPS Mode Check
1. On the GPS Navigator, enter a Direct-To flight plan to an airport that is generally in front
of the aircraft.
2. Ensure GPS is displayed as the active navigation source on the G5.
3. Engage the autopilot by pressing the AP button on the GMC 507.
4. Verify that ROL and PIT are displayed on the G5.
5. Press the NAV button on the GMC 507.
6. Verify that GPS replaces ROL on the G5.
7. Select OBS mode on the GPS navigator.
8. Adjust the OBS 3 degrees higher than the current DTK (Example: If the DTK is 272
degrees, adjust the OBS to 275 degrees).
9. Verify that the CDI moves to the left.
10. Verify that the flight director command bars indicate a left turn and that the flight controls
drive to the left.
11. Adjust the OBS three degrees lower than the current DTK.
12. Verify that the CDI moves to the right.
13. Verify that the flight director command bars indicate a right turn and that the flight
controls drive to the right.
14. Press the AP DISC/TRIM INT switch to disengage the autopilot.
15. Press the FD button to remove the flight director bars from the G5.
9.3.2.6 ILS APR Checks
1. Simulate an ILS (Localizer and Glideslope) using a ramp tester.
2. Tune the NAV radio to the Localizer frequency
3. Set the G5 to display the ILS.
4. Set the signal generator to simulate 0.093 DDM Left and 0.091 DDM Up signals.
5. Adjust the course pointer to aircraft heading.
6. Engage the autopilot by pressing the AP button on the GMC 507.
7. Verify ROL and PIT are displayed on the G5.
8. Press the APR button on the GMC 507.
9. Verify LOC and GS are displayed in white on the G5.
10. Slowly center the LOC deviation on the test set.
11. Verify that LOC turns green and ROL is extinguished on the G5.
12. Slowly center the GS deviation on the test set.
13. Verify that GS turns green and PIT is extinguished on the G5.
14. Apply left LOC deviation on the test set.
15. Verify that the flight director command bars indicate a left turn and that the flight controls
turn to the left.
GFC 500 Autopilot with ESP Part 23 AML STC Maintenance Manual
190-02291-01
Page 34
Revision 1