Ads-B Out Test (Gnx 375) - Garmin GPS 175 Maintenance Manual

8.5 ADS-B Out Test (GNX 375)

This test procedure is used to verify that the ADS-B Out parameters meet the performance requirements as
described in Title 14 Code of Federal Regulations (14 CFR) § 91.227. This test requires the use of a
Mode S transponder ramp tester, such as an Aeroflex IFR-6000 or TIC TR-220. For instructions on the
operation of the ramp test equipment, refer to the manufacturer's documentation.
1. Verify that the aircraft is in a location where a GPS signal is receivable (e.g. outdoors with a clear
view of the sky).
2. Power on the aircraft/avionics.
3. With the GNX 375 operating in Normal mode, verify that the GNX 375 has acquired GPS position
and has ADS-B Out enabled.
a. GPS signal can be verified on the System → GPS Status page.
b. ADS-B Out enablement can be verified by tapping the XPDR icon on the right side of the
screen and then tapping the Menu button at the top-left of the screen.
4. Using the transponder test set, verify the following ADS-B Out parameters are being transmitted:
a. Aircraft emitter category is Light Airplane < 15,500 pounds (On the TR-220 this is indicated
as "A1").
b. Aircraft Length documented in the aircraft Configuration Log.
c. Aircraft Width documented in aircraft Configuration Log.
d. 1090 ADS-B In Capability matches the configuration setting documented in the aircraft
Configuration Log.
e. UAT (978) ADS-B In Capability matches the configuration setting documented in the aircraft
Configuration Log.
5. Place the GNX 375 transponder into Ground Test mode to simulate an airborne state.
6. On the GNX 375 XPDR page, set the mode to Altitude Reporting.
7. Using the transponders test set, verify the following ADS-B Out parameters are being transmitted:
a. NACV > 1
b. SDA > 2
c. SIL > 3
d. NACP > 8
e. NIC > 7
8. Cycle the GNX 375 power to disable Ground Test mode.
190-02207-A2
Rev. 3
GPS 175/GNX 375/GNC 355 Part 23 AML STC Maintenance Manual
Page 8-3