Installation Considerations - Garmin GTS 8 Series Installation Manual

2.2 Installation Considerations

Fabrication of a wiring harness is required. Sound mechanical and electrical methods and practices are
required for installation of the GTS 8XX/GPS 65.
2.2.1 Antenna Considerations
Antenna installations on pressurized cabin aircraft require FAA approved installation design and
engineering substantiation data whenever such antenna installations incorporate alteration (penetration) of
the cabin pressure vessel by connector holes and/or mounting arrangements. For needed engineering
support pertaining to the design and approval of such pressurized aircraft antenna installations, it is
recommended that the installer proceed according to any of the following listed alternatives:
1. Obtain approved antenna installation design data from the aircraft manufacturer.
2. Obtain an FAA approved STC, pertaining to, and valid for the antenna installation.
3. Contact the FAA Aircraft Certification Office in the appropriate Region and request identification
of FAA Designated Engineering Representatives (DERs) who are authorized to prepare and
approve the required antenna installation engineering data.
4. Obtain FAA Advisory Circular AC-183C and identify a DER from the roster of individuals in it.
5. Contact an aviation industry organization such as the Aircraft Electronics Association for
assistance.
For all composite aircraft, antenna installation requires that a ground plane be fabricated on the internal
surface of the aircraft directly under the antenna. The TAS/TCAS antenna pattern is dependent upon a
ground plane under the antenna. The minimum recommended antenna ground plane dimensions are
18" x 18" for composite aircraft.
A fabricated doubler plate assembly supplied by the installing agent or antenna vendor may be required
inside the fuselage to complete the antenna hardware installation.
For all GTS 8XX installations, a monopole antenna is recommended if installing an
optional bottom mounted antenna on a fixed-gear aircraft, while retractable-gear aircraft
may use either a monopole or a directional bottom mounted antenna. The target bearing
accuracy may be degraded for bottom directional antenna installations on aircraft with
fixed gear.
GTS 8XX/GPA 65 Installation Manual
190-00587-00
NOTE
Page 2-3
Revision 4TP