Garmin MX20 Installation Manual - 2 Installation
Installation
MX20 Installation Manual
560-1025-09 Rev E
7
2 Installation
This section describes the installation of the MX20 including mounting, wiring, connections, and
software configuration. A post-installation checkout procedure is included at the end of this section.
2.1 Pre-Installation Information
Always follow good avionics installation practices per FAA Advisory Circulars (AC) 43.13-1B, 43.13-
2A, and AC 20-138, or later FAA approved revisions of these documents.
Follow the installation procedure in this section as it is presented for a successful installation. Read the
entire section before beginning the procedure. Prior to installation, consider the structural integrity of
the MX20 installation as defined in AC 43.13.2A, Chapter 1. Perform the post installation checkout
before closing the work area in case problems occur.
Complete an electrical load analysis in accordance with AC 43.13-1B, Chapter 11, on the aircraft prior
to starting modification to ensure aircraft has the ability to carry the MX20 load. Refer to Section 2.5.6
for the power consumption of each MX20 mode of operation (heater on). Document the results of the
electrical load analysis on FAA Form 337.
2.2 Installation Overview
A successful installation should start with careful planning including determination of mounting
location for the MX20, cable routing, and other required modifications. Once the mounting location has
been determined, prepare the mounting frames for installation. It may be easier to complete the wiring
harness and attach the connectors to the mounting frame before installing the mounting frame.
Carefully plan which external devices are to be connected to which MX20 ports observing the special
characteristics of ports 3 and 4. When data from previously installed equipment is displayed on the
MX20, or control of that equipment is accomplished by the MX20, the installer should evaluate whether
the AFMS/RFMS for the interfaced equipment needs update.
2.3 Installation Considerations
2.3.1 External Sensors
External serial data sources intended for use with the MX20 should be checked for compatibility before
installation. Devices from other manufacturers or unlisted models are supported if they adhere to the
interface specifications provided in this manual. The list of supported devices is located in Section
3.1.10 of this manual.
When the MX20 is installed with external sensors, these sensors must be installed with manufacturer’s
data. This manual does not provide information for the installation of specific external sensors.
2.3.2 Mounting Considerations
The MX20 is designed to mount in the avionics stack in the aircraft instrument panel within view and
reach of the pilot. The MX20 must be located where the operator will have easy access to the controls
and adequate viewing of the display. The preferred location would minimize pilot head movement when
transitioning between looking outside of the flight deck and viewing and operating the MX20. Sample
diagrams of typical cockpit front panel views of the MX20 are shown in Figure 2-1 and Figure 2-2.
The standard package includes a mounting frame for ease of mounting, connections, and service of the
unit. Allow an additional one-inch clearance to the rear of the mounting frame for connectors and
cables. Mounting frame details are shown in Figure 2-3, Figure 2-4, Figure 2-5, and Figure 2-7. Use of