Visual Inspection; Electrical Bonding Test - Garmin G3X Touch Maintenance Manual

4.4 Visual Inspection

Operation of the G3X Touch system is not permitted unless a visual inspection, as described in this
section, has been completed within the preceding 12 calendar months. Check for corrosion, damage, or
other defects for each of the G3X Touch LRUs. Replace any damaged parts as required. Inspection may
require the temporary removal of a unit or units to gain access to connectors. Follow guidance in Section
6 for equipment removal and replacement.
Conduct the following visual inspection of the G3X Touch EFIS system LRUs and associated wiring
harnesses to ensure installation integrity:
1. Inspect all units for security of attachment, including visual inspection of brackets and other
supporting structure attaching all units to the airframe.
2. Inspect all switches, annunciators, knobs, and buttons for legibility.
3. Inspect displays for legibility and acceptable brightness. Reference Section 5.3.1.
4. Visually inspect each unit's wiring (including electrical bonding straps), overbraid, and connectors
for chafing, deterioration, damage, or wear.
5. Visually check for any signs of corrosion.
4.4.1 Aluminum Foil Tape (Non-metallic Aircraft Only)
Any aluminum foil tape if used in the G3X Touch installation for grounding of a GSU 25D, GEA 24, GAD
29B or GAD 27, (refer to Appendix A of this document) must be inspected every 12 calendar months.
The inspection must verify that the foil tape is not torn, damaged, or showing signs of corrosion. If any of
these conditions are found, the tape must be replaced in accordance with Section 4 of G3X Touch EFIS
Part 23 AML STC Installation Manual.

4.5 Electrical Bonding Test

G3X Touch EFIS LRU electrical bonding must be checked every 2,000 flight hours or 10 years, whichever
occurs first.
4.5.1 Requirements

Disconnect any cables and connectors normally attached to the LRU.

Resistance must be measured from a bare metal portion of the LRU to an airframe grounding
location.
The airframe grounding location should be as close to the LRU as possible, unless otherwise noted in
Table 4-2.
4.5.2 Test Equipment
Calibrated 4 wire Milliohm meter and Kelvin probes are required for this test.
4.5.3 Electrical Bonding Test Procedures.

Using a calibrated milliohm meter and Kelvin probes measure the resistance of each G3X Touch
LRU between the locations noted in

Table 4-2, and record the result of each installed LRU. Some equipment on the list are optional
and may not be installed.

Ensure the resistance does not exceed 10 milliohms.

If the measured resistance is greater 10 milliohms, bonding must be improved to meet applicable
requirements for a new installation in accordance with Section 4 of G3X Touch EFIS Part 23 AML
STC Installation Manual (190-02472-01).
Maintenance Manual
G3X Touch EFIS Part 23 AML STC
Page 29
190-02472-02
Revision 2