Installation Requirements; Installation Considerations; Mounting Requirements - Garmin G900X Installation And Maintenance Manual

7.5 Installation Requirements

7.5.1 Equipment Available
Sub Assy, Connector Kit, GRS 77 w/Shield Block
Installation Rack, GRS 77
Sub Assy, Connector Kit, GMU 44
Installation Rack, GMU 44

7.6 Installation Considerations

Fabrication of a wiring harness is required. Sound mechanical and electrical methods and practices are
required for installation of the GRS 77 and GMU 44.
7.6.1 Consideration for Wing Grounded Lighting Fixtures
The following installation practices are recommended if the required GMU 44 mounting bracket is
located in the wing.
1. The wing tip lights should not have a power ground referenced to the chassis of the light
assembly that would then be referenced back to the airframe ground via the light assembly
mounting.
2. A dedicated power ground should be used and returned as a twisted pair with the power source
back into the fuselage for a wing mounted GMU 44.
These installation practices will prevent magnetically interfering currents from flowing in the wing skin
that encloses the GMU 44. Electrically isolating the light assembly should not be used as an alternative to
item 1 above, unless the isolated light assembly has been analyzed for adequate protection against direct
attachment of lightning.
Refer to Appendix B for approved G900X airframe specific GMU 44 mounting locations.

7.7 Mounting Requirements

The following guidelines describe proper mechanical installation of the Garmin GRS 77 AHRS and
GMU 44 Magnetometer. The guidelines include requirements for proper location selection in the aircraft,
requirements for supporting structure and mechanical alignment and restriction on nearby equipment.
G900X/G950 Installation and Maintenance Manual – GRS 77 and GMU 44
190-00719-00
Table 7-6. GRS 77/GMU 44 Accessories
Item Garmin P/N
011-00869-01
115-00459-00
011-00871-00
115-00481-00
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Revision D