(2020) Service Advisory 2085: ADS-B

PRODUCTS AFFECTED:

GTX 23ES, 33ES, 35R, 45R, 330ES, 335/335R and GTX 345/345R transponders installed with a G3X operating outside of the United States are affected.

ISSUE:

GTX 23ES, 33ES, 35R, 45R, 330ES, 335/335R and GTX 345/345R transponders are designed to standards that require a conforming GPS source to transmit conforming ADS-B OUT (per FAA AC 20-165B and EASA CS-STAN).

The G3X GPS is not a conforming GPS source. All G3X GPS ADS-B OUT targets are ignored by certified ADS-B IN systems.

At this time a G3X installed with a GTX 45 or GTX 345/345R configured as the ADS-B IN source is not able to display non-conforming ADS-B OUT targets.

ACTION:

To transmit conforming ADS-B OUT, all Garmin transponder products must be interfaced to a conforming GPS source. For the G3X, a GPS 20A provides a conforming GPS source for ADS-B OUT. The GTX 335 w/GPS, GTX 335R w/GPS, GTX 345 w/GPS, and GTX 345R w/GPS transponders also provide a conforming GPS source, as well as the GNS 4XXW/5XXW and the GTN 6XX/7XX.

To display non-conforming ADS-B OUT targets on a G3X system with a GTX 45 or GTX 345/345R, a GDL 50 (non-certified ADS-B receiver) must be configured as the ADS-B IN source.

RESOLUTION:

An upcoming software change will enable the display of non-conforming ADS-B OUT targets when GTX 45 or GTX 345/345R is configured as the ADS-B IN source.