Garmin GRA 55 Maintenance Manual - Page 25

Table 4-2. Maintenance Intervals for Antennas Replaced Under this STC Item Description/Procedure Interval An electrical bonding test must be performed on antennas installed by this STC. 1. Gain access to the antenna installation. 2. Remove one each mounting screw from the antenna if not already done. Check that the remaining hardware is installed and properly torqued. 3. Measure the resistance between the exposed metal in the empty mounting hole of the antenna and a nearby exposed portion of conductive aircraft structure (i.e. exposed rivet). Verify that the resistance is less than or equal to 2.5 milliohms. 4. Reinstall the antenna mounting screw, torque as specified. Reseal the antenna as required. In the event of a bonding test failure, remove the failed antenna, Clean and inspect all hardware and mating surfaces using approved solvents and methods per Bell specification BHT-ELEC-SPM CHP 8. To be performed in alignment with Bell Test - Bonding Check, Antennas For antennas that are secured with nuts and bolts, clean the fastener hole in the antenna and the underside of the fastener head itself. Prep the area underneath the washer on the inner mould line of the skin in accordance with Bell Specification BHT-ELEC-SPM CHP 8. If nutplates are used in lieu of 206B, 206L series maintenance schedule. Every 10 years or every 2000 hours, whichever comes first. a nut, the technician is only required to clean the underneath of the fastener head and the fastener hole. For antennas that use stud mounts, prep the area underneath the washer on the inner mould line of the skin in accordance with Bell Specification BHT-ELEC-SPM CHP 8. Re-install using Antenna Installation procedures in Section 6.3. Any reworked antenna installation shall have a resistance of less than or equal to 2.5 milliohms. Re-seal the antenna as per methods specified in BHT-ELEC-SPM CHP 8. 190-01277-A3 Rev. 1 System Maintenance Manual GRA 55/5500 Bell 206 STC Page 4-5