Limitations; Operation; Installation; Gps Antenna - Garmin MX20 Installation Manual

Limitations

4 Limitations

4.1 Operation

There are no Part 23 aircraft type limitations. All functions of the MX20 meet the appropriate design
assurance qualifications for a secondary system for airplanes in Class I, Class II, Class III, and Class IV in
accordance with AC 23.1309-1C, Figure 2. The TSO authorizations with the RTCA/DO178B software
levels by function are listed in Section 1.3.

4.2 Installation

The conditions and tests required for TSO approval of this article are minimum performance standards. It is
the responsibility of those installing this article either on or within a specific type or class of aircraft to
determine that the aircraft installation conditions are within the TSO standards. TSO articles must have
separate approval for installation in an aircraft. The article may be installed only if performed under 14 CFR
Part 43 or the applicable airworthiness requirements.
If it is necessary to move any required instrumentation in an instrument panel to make room for the MX20,
although the physical mounting of the MX20 is covered within this installation manual, the relocation of
these instruments is beyond the scope of the STC.
For installations where a stack is not already installed in the aircraft or the alternate mounting configuration
depicted in Figure 2-4 is implemented, a separate structural approval is needed for installation of the stack.
Any other alternate mounting configuration is beyond the scope of this STC.
For preservation of essential equipment in aircraft with multiple power busses the MX20 should be powered
from the non-essential bus.

4.3 GPS Antenna

The MX20 with internal GPS receiver (430-0270-0( )) is compatible only with the Garmin AT A-33 (590-
1104) or A-34 (590-1112) antennas, or those with equivalent specifications. Refer to section 3.3 for
specifications.
4.4 Antenna Installation – General
Antenna installation in the pressure vessel of pressurized aircraft is beyond the scope of the MX20 STC.
Additional manufacturer's data may be necessary and FAA approval may be required to cover the
installation of any antenna in the pressure vessel of a pressurized aircraft.

4.5 Traffic Sensor

Only one traffic sensor may be connected to the MX20. Refer to Section 3.1.10 for a list of compatible
sensors. If the MX20 is interfaced to the Garmin GDL 90, and the aircraft has an operating transponder, the
GDL 90 Code Edit option must be disabled (see Section 2.7.4, Step 10). Only one device installed in the
aircraft can be the entry point for ATC-assigned squawk codes.

4.6 FIS Sensor

Only one FIS sensor may be connected to the MX20. Refer to Section 3.1.10 for a list of compatible
sensors.
MX20 Installation Manual 560-1025-09 Rev E 57