Regulatory Test; Gtx 3X5 Airborne Mode - Garmin GTX 330D Maintenance Manual

5. After tests are completed, reconfigure the transponder and the GNS 480 back to their original
settings.
8.5.2

GTX 3X5 Airborne Mode

The transponder must be placed in an airborne state to reply to any Mode A or Mode C interrogations. The
GTX uses advanced Air/Ground logic to determine the state of the transponder. This logic must be
temporarily defeated in order to place the transponder in an airborne state for testing. To place the
transponder into an airborne state, perform the following procedure for the GTX interface installed in the
aircraft.
Panel Mounted Transponder
1. Start the GTX in Ground Test mode (hold the CRSR key and press the ON key).
2. A "GROUND TEST MODE" alert message will be displayed on the GTX 3X5 message screen.
Remote Mounted Transponder (GTN Interface)
1. Start the GTN in configuration mode (hold the HOME key while cycling power).
2. Navigate to the XPDR 1 Installation Settings page and press the Force Airborne Test key.
3. Restart the GTN in normal mode.
Remote Mounted Transponder (GTX 3X5R, GNS 480 Interface)
1. Connect the GTX 3X5 installation tool to the GTX 3X5R unit.
2. Place unit into ground test mode located on the state page.
Remote Mounted Transponder (GTX 3X5R, G1000/G950 Interface)
1. Connect the GTX 3X5 installation tool to the GTX 3X5R unit.
2. Place unit into ground test mode located on the state page.
Remote Mounted Transponder (GTX 3X5R, G1000/G950 Interface w/GDU sw v15.00 and higher)
The following is a method of placing a GTX 3X5 in an airborne state while on the ground without the use
of the GTX 3X5 Install Tool.
1. Place the MFD in normal mode and place only the PFD 1 in configuration mode.
2. Go to the Transponder Configuration page and press the GND TEST soft key (only enabled when
the aircraft is detected as on the ground).
3. Cycle the power on the PFD 1 only after the GND TEST soft key is pressed, ensuring power
remains applied to the other displays.
8.6
The transponder is now in an airborne state for test purposes. Cycle aircraft power to take it out of
ground test mode.
With the transponder operating in normal mode and in an airborne state (refer to section 8.5), the following
regulatory tests are required to be performed every 24 calendar months.
1. Altitude reporting equipment tests in accordance with 14 CFR Part 91.411 and Part 43
appendix E.
2. ATC transponder tests and inspections in accordance with 14 CFR Part 91.413 and Part 43
appendix F.
If the transponder is removed, replaced, or modified, sufficient testing in accordance with Part 23 appendix
190-00734-11
Rev. 6

Regulatory Test

GTX 33X and GTX 3X5 ADS-B Maintenance Manual
Page 8-4