On Friday, January 6, 2017 at 5:28:59 PM UTC-8, wrote:
Darryl,

If the glider is experimental...

Could you supply the ADSB Out capable transponder with NMEA GPS data from a GPS source such as a CNv or Powerflarm, etc.? I agree that the TN72 is affordable, but if experimental, is it necessary?


Separately, someone posted a comment which came from Trig which says the lower power Trig is acceptable for experimental gliders. Do you agree with that comment?

The TN72 gets you more than any random consumer/NMEA GPS source will. Like display of your aircraft on the ADS-B In traffic displays in certified aircraft. So yes as a part of the whole ADS-B thing being a overly complex mess, you want to be as compliant as possible and this TABS stuff is better than random consumer stuff.

The Trig TT-21 (what I assume you mean by lower-power here) is fine for this "TABS" use in experimental aircraft. You can't use a TT-21 to meet any 2020 ADS-B Out compliance needs, but you are not doing that here, you are just using it to transmit (lower-power) 1090ES Out. That it happens to be TSO-C199/TABS complaint is irrelevant now in a regulations sense since there are no install or use regulations that affects.... and that's the issue with certified gliders today is there are is no TABS install regulations and (if needed) STCs that let you do that install. I hope the FAA addresses.

If you have a Trig transponder in an experimental glider I'd reach out to Trig and do exactly what they said to with the TN72. They know what they are doing, worked with the FAA on the development of TSO-C199 etc.