190-01007-C1
GTN Xi Part 23 AML STC Maintenance Manual
Rev. 1
Page 4-7
In the event of bonding test failure, remove the GTN Xi rack, clean the attachment points with a bonding
brush at both the rack and the aircraft, and re-attach the rack to the rails in the panel. Measure the
resistance between the mounting rack and the instrument panel and ensure that the resistance is less than or
equal to 5 mΩ.
4. Re-install the backplate assembly and re-install the GTN Xi unit in the mounting rack.
4.5.3 GMA 35 Bonding Check (Metallic or Tube-and-Fabric Aircraft)
NOTE
A bonding test failure may occur if a fastener is not secured to the specified torque value.
For installations that use screws in lieu of rivets to secure the rack to surrounding
structure, verify that the screws are torqued to the appropriate value before proceeding to
remove the rack. Refer to Section 4.4 for torque values.
NOTE
The GTN 7XX Xi backplate assembly must be removed from the GTN Xi rack prior to
performing step 4.
A bonding check is required for the GMA 35. Perform an electrical bonding check as follows:
1. Gain access to the GMA 35 by removing the GTN 7XX Xi unit.
2. Remove the GMA 35 unit from the mounting rack.
3. Remove backplate assembly from the rack.
4. Measure the resistance between the mounting rack and nearby exposed portion of aircraft metallic
structure, and verify that it is less than or equal to 5 mΩ.
In the event of bonding test failure, remove the GMA 35 rack and clean the attachment points with a
bonding brush at both the rack and the aircraft attachment points. Measure the resistance between the
mounting rack and nearby exposed portion of aircraft metallic structure and ensure that the resistance is
less than or equal to 2.5 mΩ.
5. Re-install the backplate assembly and re-install the GMA 35 unit in the mounting rack.
4.5.4 GMA 35 Bonding Check (Composite Aircraft)
NOTE
A bonding test failure may occur if a fastener is not secured to the specified torque value.
For installations that use screws in lieu of rivets to secure the rack to surrounding
structure, verify that the screws are torqued to the appropriate value before proceeding to
remove the rack. Refer to Section 4.4 for torque values.
NOTE
The GTN 7XX Xi backplate assembly must be removed from the GTN Xi rack prior to
performing step 4.
1. Gain access to the GMA 35 by removing the GTN 7XX Xi unit.
2. Remove the GMA unit from the mounting rack.
3. Remove the backplate assembly from the rack.
