Garmin GFC 500 Maintenance Manual page 36

13. Ensure that the flight director command bars indicate a pitch down and that the pitch
servo drives the controls in a nose down direction.
14. Firmly grasp the control wheel and press the AP DISC/TRIM INT switch on the pilot's
flight controls.
15. Verify that the autopilot disconnects and the pitch control moves freely.
9.3.1.3 Pitch Trim Servo Functional Check (If Installed)
1. Verify that the steps in Section 9.3.1 have been completed.
2. Press the TRIM switch on the pilot's flight controls in the NOSE UP direction.
3. Verify that the trim runs in the nose up direction.
4. While the trim is running, depress the AP DISC/TRIM INT switch on the pilot's flight
controls and verify that the pitch trim stops running.
5. Press the TRIM switch on the pilot's flight controls in the NOSE DN direction.
6. Verify that the trim runs in the nose down direction.
7. Adjust the trim all the way to the nose down stop.
8. While monitoring elapsed time, actuate the TRIM Switch on the pilot's flight controls in
the NOSE UP direction until the trim runs against the nose up mechanical stop.
9. Verify that the elapsed time for full travel of the pitch trim is within the range specified in
the appropriate model-specific installation manual addendum (190-02291-XX). If the
elapsed time is not within the specified range, refer to Section 5.2 in this manual.
10. While monitoring elapsed time, actuate the TRIM Switch on the pilot's flight controls in
the NOSE DN direction until the trim runs against the nose down mechanical stop.
11. Verify that the elapsed time for full travel of the pitch trim is within the range specified in
the appropriate model-specific installation manual addendum (190-02291-XX). If the
elapsed time is not within the specified range, refer to Section 5.2 in this manual.
9.3.2 GFC 500 Functional Checks
Perform the following test procedures when the GMC 507 is replaced.
9.3.2.1 Autopilot Switch Checks
1. Power up the system in normal mode.
2. Complete Pre-Flight Test (PFT) as shown in Section 9.2.
3. Actuate the TRIM switch on the pilot's flight controls in the nose down (forward)
direction.
4. Verify that the Pitch Trim Servo engages and drives the airplane trim system in a Nose
Down direction.
5. Release the TRIM Switch.
6. Actuate the TRIM switch on the pilot's flight controls in the nose up (aft) direction.
7. Verify that the Pitch Trim Servo engages and drives the airplane trim system in a Nose
Up direction.
8. Release the TRIM switch.
GFC 500 Autopilot with ESP Part 23 AML STC Maintenance Manual
190-02291-01
Page 29
Revision 1