Garmin GMX 200 Installation Manual - page 17
GMX 200 Installation Manual
Page 2-3
190-00607-04 Revision
D
2.4.2.2 Altitude Source
The GMX 200 uses altitude for its terrain awareness function and for calculating absolute altitudes for
traffic. Only one type of altitude (GPS or pressure) can be configured for use by the GMX 200. An
external altitude source (either GPS or pressure) is required if any of the following features is configured:
•
The GMX 200 terrain awareness function is used (i.e. an external TAWS source is not
configured)
•
A Ryan TCAD is configured as the traffic source (altitude is only used to calculate the absolute
altitude for traffic).
2.4.2.2.1 GPS Altitude
If the Altitude Type is set to GPS, the GMX 200 uses GPS Altitude for all of its calculations (if pressure
altitude is also available to the GMX 200, it will not be used). If a GDL 90 is connected, the GMX 200
will use the GPS Altitude from the GDL 90 as a second altitude source, and the altitude source with the
highest integrity will be used for all calculations.
2.4.2.2.2 Pressure Altitude
If the Altitude Type is set to Pressure, the GMX 200 uses Pressure Altitude for all of its calculations (if
GPS Altitude is also available to the GMX 200, it will not be used).
2.4.3 Mounting Considerations
The GMX 200 is designed to mount in the avionics stack in the aircraft instrument panel within view and
reach of the pilot. The GMX 200 must be located where the operator will have easy access to the controls
and adequate viewing of the display meeting the installation limitations in section 7.2. The preferred
location would minimize pilot head movement when transitioning between looking outside of the flight
deck and viewing and operating the GMX 200. Reference Figure D-4. A sample diagram of a typical
cockpit front panel view of the GMX 200 is shown in Figure D-2. The GMX 200 should be placed as
high as possible in the radio stack to minimize the shifting of colors on the display. The audio panel
should be the only equipment above the GMX 200.
The standard package includes a mounting tube for ease of mounting, connections, and service of the unit.
Allow an additional 2” clearance to the rear of the mounting tube for routing cables. Mounting tube
details are shown in Figure D-5 and Figure D-6.
2.4.4 Cable and Wiring Considerations
Wiring should be installed in accordance with AC 43.13-1B Chapter 11. When wire separation cannot be
achieved, the following issues should be addressed:
•
The cable harness should not be located near flight control cables and control, high electrical
capacity lines or fuel lines
•
The cable harness should be located in a protected area of the aircraft
•
Do not route cable near high-energy sources
2.4.5 Air Circulation and Cooling
The GMX 200 does not required external cooling, but mounting configuration should not restrict intake
airflow into the duct above the I/O D-sub connector or exhaust airflow out of the exhaust fans. Reference
Figure D-6 for exhaust fan and air duct locations.
2.4.6 Compass Safe Distance
After reconfiguring the avionics in the cockpit panel, if the GMX 200 is mounted less than six inches
from the compass, recalibrate the compass and make the necessary changes for noting correction data.