Installation Instructions

190-01007-A3 GTN 6XX/7XX AML STC Installation Manual
Rev. 4 Page G-1
Appendix G Lightning Protection
G.1 Lightning Protection in Metal Aircraft
G.1.1 HSDB Weather Radar Interface
When interfacing the GTN 6XX/7XX to an HSDB weather radar (WXR), overbraid is required over any
HSDB cabling in the radome area prior to entering the metal fuselage (or metallic wing). Any wiring for
weather radar configuration modules does not require overbraid as part of this STC. This
section describes how to install the overbraid for the WXR cabling.
The GTN may be interfaced to a weather radar in metal aircraft only. Nonmetallic aircraft
(see Table G-1) must not interface the GTN to a weather radar.
Refer to Appendix E for weather radar interconnect information.
NOTE
Refer to Table G-1 to determine if the aircraft is classified as metal or nonmetallic.
G.1.1.1 Materials Required but Not Supplied
The following materials (or equivalents) are required to install WXR cabling overbraid in the radome
area:
• Tinned copper flat braid, 3/4”, QQB575F36T0781 (recommended)
OR
Tinned copper tubular braid, 7/16”, QQB575R30T0437
• Electrical tie-down strap, adjustable, MS3367-{1, 2, or 7}-X
• Terminal lug, 5/16”, uninsulated, MS20659-131
• Terminal stud, 5/16” (or equivalent 5/16” bolt/nut)
• NAS970-516 (AN970-516) washer
G.1.1.2 Overbraid Installation Procedure
NOTE
The length of overbraid required is approximately equal to the length of the WXR
cabling in the radome area (measured from the bulkhead or metallic wing entry area
to the WXR R/T connector) plus six inches.
Refer to Figure G-1 and Figure G-2 while completing the following overbraid installation procedure:
1. Remove the backshell from the WXR R/T connector and save for reinstallation. This will allow
the overbraid to slide over the cable without unpinning the connector.
2. Slide the overbraid onto the cable from the WXR R/T to the bulkhead (or grounding provisions at
the metallic wing entry area).
3. Reinstall the WXR R/T connector backshell body.
4. At the WXR R/T end of the overbraid, fold one inch of overbraid back over itself. Position the
overbraid so that the fold will lie under the backshell cover plate, while the overbraid ends will lie
just outside the strain relief bar. Refer to Figure G-1.
5. Install the backshell cover plate and strain relief bar.