Garmin GI 275 Installation Manual page 253

p. Disengage the autopilot.
q. Verify the roll attitude calibration:
i. Set the internal AHRS Output to 0° UP and 20° RT.
ii. Verify that the Roll value on the KC 225 RTI is 20° (±0.5°).
iii. Set the internal AHRS Output to 0° UP and 20° LT.
iv. Verify that the Roll value on the KC 225 RTI is -20° (±0.5°).
v. If both Roll attitude values are not within tolerance, adjust the ROL potentiometer on the
side of the KC 225 until both Roll attitude values are within tolerance.
r. At the completion of test, remove the KC 225 extender harness.
Example Adjustment:
Pitch Offset: 0.67°
With 10°U pitch, adjust the PIT potentiometer
until the displayed Pitch value is between
10.17° and 11.17°.
(This range is equal to [10° + 0.67°] ±0.5°)
Heading and Course Pointer Calibration
1. Navigate to the Autopilot Test page (Calibration/Test → Autopilot → Test).
2. Activate the HDG/CRS Valid discrete.
3. Set the Heading Datum (HDG) and Course Datum (CRS) to 360°.
4. On the KC 225 RTI, select the Installation Offset function.
a. Touch 1. Heading on the Set Installation Offsets page and then touch ENTER.
b. Touch 2. Course on the Set Installation Offsets page and then touch ENTER.
Touch ENTER to exit the page.
FD Alignment
1. Verify that the attitude input to the autopilot is level (i.e., zero pitch/roll).
a. If using the GI 275, verify that the output test values are 0° UP, 0° RT, and Attitude Valid on
the Gyro Output Test page (Calibration/Test → Autopilot → Gyro Output Test).
b. If using an analog gyro, verify the gyro is operational and level. This may require an extender
harness and tilt table.
2. Navigate to the GI 275 Flight Director Calibration page to view the FD Pitch and FD Roll values
(Calibration/Test → Autopilot → Flight Director).
3. Align FD Pitch as follows:
a. Verify the FD is engaged, and that the autopilot is not engaged.
b. Press and hold CWS.
c. Adjust the potentiometer on the front of the KC 225 until the FD Pitch value is as close to zero
as possible.
4. Align FD Roll as follows:
a. Verify the autopilot and flight director are disengaged.
b. Press and hold the FD button on the KC 225.
c. Adjust potentiometer on the KC 225 until the FD Roll value is as close to zero as possible.
190-02246-10
Rev. 11
Roll Offset: -0.34°
With 20°R roll, adjust the ROL potentiometer
until the displayed Roll value is between 19.16°
and 20.16°.
(This range is equal to [20° + (-0.34°)] ±0.5°)
GI 275 Part 23 AML STC Installation Manual
Page 5-75