Electrical Bonding Test; Figure 8. Bonding Check - Garmin GTX 330 System Maintenance Manual

3) Inspect any bonding straps for corrosion, loose connections, or signs of damage.
4) Inspect the condition of the wiring harnesses and coaxial cables.
a. Verify that all wiring and cables are securely fastened.
b. Verify that the harness shows no signs of cracking, chaffing, abrasion, melting, or any other form
of damage.
Antenna Visual Inspection
During normal aircraft inspections not to exceed 12 calendar month intervals, conduct a visual inspection
of the transponder antennas for the following:
1) Leading edge erosion, cracks, dents, or broken antenna. If present, antenna must be replaced.
2) If the attachment is not secure, re-work the installation and complete electrical bonding test specified
in Section 4.6.
3) Condition of base seals. In the event the antenna seal shows sign of damage or decomposition, re-seal
and complete the Electrical bonding test specified in Section 4.6.
Post Lightning Strike Inspection
A post lightning strike inspection must be done for a suspected or actual lightning strike to antennas.
Inspect antenna and surrounding installation to ensure that there is no structural damage around the areas
where lightning may have attached. If there is visible sign of damage to the antenna, then it should be
replaced.
4.6

ELECTRICAL BONDING TEST

A milliohm meter and Kelvin probes are recommended for this test. However, a standard voltmeter,
power supply with adjustable current limit and ammeter may be substituted. The following procedure is
written using the voltmeter, power supply and ammeter. All test equipment must have valid calibration
records.
Procedures
1. Connect the positive lead of the power supply to the engine compartment grounding bracket (battery
negative connection to the airframe). Connect/touch the positive lead of the voltmeter to the same
point.
190-00734-11
Rev. 1
The document reference is online, please check the correspondence between the online documentation and the printed version.

Figure 8. Bonding Check

4-5
GTX 330/33 with ADS-B Out
Maintenance Manual with ICA