Non-Structural Mount Installation - Garmin G3X Installation Manual

20.6

Non-Structural Mount Installation

This section provides installation examples and considerations for non-structural mounting of teardrop and
ARINC 743 footprint antennas. Typical installations may be below a non-metallic glareshield, under the
composite or fabric skin, or on an external, non-structural surface. Other non-structural installations may
exist, but are not presented in this manual.
External mounting of the antenna is preferred, although the antenna can be mounted inside the aircraft.
When mounted internally, the antenna does not have to be aligned with the aircraft forward direction, but
should be equal to the aircraft typical cruise attitude.
There should be a solid mechanical base in the mounting area for the antenna, and existing surfaces or
brackets may be used with the doubler plate. Alternately, non-structural brackets may be fabricated in the
field as necessary to mount the antenna. Brackets should be made of minimum 0.032" thickness aluminum
and should span as short a distance as possible.
Some fabric aircraft include aluminum paste in the fabric finishing process, often referred to as "silver
coats". Presence of thick fabric and/or heavy "silver coats" may degrade the signal strength of the antenna.
20.6.1 Generic Non-structural Antenna Installation
Figure 20-25 shows the generic non-structural installation for the ARINC 743 footprint (GA 36, GA 37,
GA 55A/GA 57X) antenna. The teardrop footprint antennas (GA 35, GA 55, GA 56 stud mount) can also
be installed in this manner.
For mounting the teardrop style antenna (GA 35, GA 55, or GA 56), a doubler plate similar to Figure 20-4
or P/N 115-00846-10 can be used with the mounting surface to support the antenna. Rivets used to secure
the doubler plate to the mounting surface are optional in a non-structural installation. Screws, washers,
and locking nuts as shown in the outline and installation drawings in Section 20.7 are required to secure the
Teardrop style antenna to the mounting surface. Torque the locking nuts to 12-15 in-lbs, torque should be
applied evenly across all mounting studs.
A doubler plate similar to Figure 20-11, or P/N 115-00846-00 (ARINC 743 style) can be used with the
mounting surface to support the antenna. Rivets used to secure the doubler plate to the mounting surface
are optional in a non-structural installation. Locking nuts are required to secure the ARINC 743 antenna
(locking nuts installed on doubler). Torque the four supplied #10-32 stainless steel screws (Garmin P/N:
211-60212-20, MS51958-67, or equivalent) evenly across all mounting screws.
190-01115-01 G3X/G3X Touch Installation Manual - GPS/XM Antenna Installation
Rev. AA Page 20-25