Gmu 44B Removal; Gmu 44B Re-Installation; Gmu 44B Checkout - Garmin GI 275 Maintenance Manual

NOTE
Removal, re-installation, or replacement of the GMU 44B will require a recalibration of
the AHRS. Additionally, any removal or addition of electrical components or ferrous
materials within 10 feet of the GMU 44B will require recalibration of the AHRS.
5.8.1

GMU 44B Removal

To remove the GMU 44B, perform the following procedure:
1. Remove power from the GI 275 directly connected to the GMU 44B.
2. Disconnect the GMU 44B connector.
3. Remove the three screws shown in Figure 5-12.
4. Remove the GMU 44B from the mounting bracket.
5.8.2

GMU 44B Re-installation

NOTE
If reusing the original mounting screws, the anti-rotation properties of the mounting
screws must be restored. This may be done by replacing the screws with new Garmin
P/N 211-60037-08. If original screws are reused, coat screw threads with Loctite 242
(blue) thread-locking compound (Garmin P/N 291-00023-02) or equivalent.
To re-install the GMU 44B, perform the following procedure:
1. Place the GMU 44B in the mounting bracket.
2. Install the three screws and torque to the specifications shown in Figure 5-12.
3. Connect the GMU 44B electrical connector.
4. Restore power to the GI 275.
5. Perform the checkout procedure in Section 5.8.3.
5.8.3

GMU 44B Checkout

Perform the following AHRS ground checks found in Section 6 of GI 275 Part 23 AML STC Installation
Manual (P/N 190-02246-10) to return the aircraft to service:
• Magnetometer Calibration
• Compass Swing
• Heading Offset Compensation (if required by the previous step)
• Engine Run-up Vibration Check
190-02246-11
Rev. 1
GI 275 Part 23 AML STC Maintenance Manual
Page 5-21