Autopilot Ground Checks - Garmin GI 275 Installation Manual

6.3.9

Autopilot Ground Checks

Before proceeding with the autopilot interface tests, verify the display has been properly configured for the
autopilot (and flight director, if applicable) that is installed. For configuration instructions, refer to
Appendix C. Only those interfaces that are directly affected by the GI 275 STC are covered by this manual;
if any other autopilot modifications have been made, those changes are outside the scope of this STC and
must be checked in accordance with the autopilot installation manual.
WARNING
It is important the display be properly configured to prevent damage to the autopilot computer.
6.3.9.1 Autopilot Engagement Check
This section verifies that the autopilot can be engaged.
1. Power on the GI 275 system in Normal mode. Allow the PFD to obtain a valid heading, attitude,
altitude, and GPS location (from the navigator).
2. Verify the GPS navigator is in Normal mode.
3. Engage the autopilot. If the autopilot cannot be engaged, troubleshoot using the instructions in the
autopilot installation manual.
4. For installations utilizing the GI 275 to provide attitude information to the autopilot, verify that the
autopilot disconnects and the servos disengage (Menu → Test → AP DISC).
5. For all other installations, disengage the autopilot using regular means.
6.3.9.2 Flight Director Check
This section verifies that the flight director interface between the autopilot computer and the display is
functional. This test only needs to be performed if:
• Analog flight director outputs are being sent to the display
• The GI 275 is configured to display the flight director
1. Power on the GI 275 PFD in Normal mode.
2. Activate the flight director with the autopilot in Pitch/Roll or Heading/Altitude mode (it is not
necessary for the servos to be engaged for this test).
3. Verify that the flight director is displayed on each applicable display. If the flight director is not
displayed, troubleshoot using the guidelines in the GI 275 maintenance manual.
4. Command the flight director to pitch up.
5. Verify that the command bars move up.
• If the flight director response is opposite (i.e., the command bars move down rather than up),
the Pitch Polarity can be changed in Configuration mode (Calibration/Test → Autopilot →
Flight Director → Pitch Polarity).
6. Command the flight director to pitch down.
7. Verify that the command bars move down.
8. Command the flight director to roll right.
9. Verify that the command bars move to the right.
• If the flight director response is opposite, the Roll Polarity can be changed in Configuration
mode (Calibration/Test → Autopilot → Flight Director → Roll Polarity).
10. Command the flight director to roll left.
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Rev. 11
GI 275 Part 23 AML STC Installation Manual
Page 6-16