According to Scotland-based Trig Avionics, “A UAT solution will often be more expensive” than a 1090ES-based solution because the latter uses relatively common Mode S transponders: The 978 UAT standard employs a separate transceiver—and U.S. operators complying with ADS-B OUT via 978 UAT still will need a Mode A/C transponder in the foreseeable future, until the FAA says otherwise.
For many general aviation operators—e.g., those operating below FL180—an ideal solution may be an “all-in-one” box incorporating WAAS-enhanced GPS and a 978 UAT transceiver, plus a means by which the ADS-B IN weather and traffic information can be displayed. Examples pictured here include FreeFlight Systems RANGR 978 product line (top) and Garmin International’s GDL 88.
