System Maintenance Manual

G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air Page 6-5
190-00682-01 Revision G
6.8 GRS 77 AHRS
Removal:
1. Gain access to the forward avionics compartment in the nose of the aircraft.
2. Disconnect the AHRS connector.
3. Remove the four Phillips thumbscrews with a screwdriver and set them aside.
4. Gently lift the GRS 77 from the mounting rack. (If the mounting rack is removed, the GRS 77
must be re-calibrated. Do not loosen mounting bolts. See Section 7.7)
Reinstallation:
1. Visually inspect the connectors to ensure there are no bent or damaged pins. Repair any
damage.
2. Place the GRS 77 on the mounting plate, ensuring the orientation is correct.
3. Fasten the unit to the plate using the Phillips thumbscrews.
4. Connect the connector to the GRS 77.
5. Calibrate, and test the GRS 77 according to Section 7.7.
6.9 GMU 44 Magnetometer
Removal:
1. Gain access to the GMU 44 units by removing the antenna panel located on the port side of the
vertical stabilizer.
2. Loosen three screws connecting the unit to the aircraft mounting bracket using a non-magnetic
Phillips screwdriver.
3. Disconnect the wiring harness.
Reinstallation
1. Visually inspect the connectors to ensure there are no bent or damaged pins. Repair any
damage. Connect the wiring harness to the GMU 44.
2. Fasten the GMU to the aircraft mounting bracket using a non-magnetic Phillips screwdriver.
3. Calibrate and test the GMU 44 according to Section 7.7.
6.10 GDL 69A
Removal:
1. Gain access by removing the appropriate GDU 1040A display unit (see Section 6.1.)
2. Unlock the GDL 69A handle by loosening the Phillips screw on the handle.
3. Pull the handle upward to unlock the GDL 69A. Gently remove the unit from the rack.
Reinstallation:
1. Visually inspect the connectors to ensure there are no bent or damaged pins. Repair any
damage.
2. Gently insert the GDL 69A into its rack. The handle should engage the dogleg track.
3. Press down on the GDL 69A handle to lock the unit into the rack.