On Saturday, September 30, 2017 at 2:23:52 PM UTC-7, wrote:
So is it possible that UAT will be abandoned and everybody move to 1090ES? And then the FAA will stop mirroring the info as ADS-R to the UAT frequency? If that happens, will the existing PowerFLARM devices become useless (other than flarm-to-flarm warnings)?

UAT won't be abandoned, there is clearly significant use out there. And the FAA/and its' contractors and owners have already invested a huge amount in all this infrastructure. This discussion went off on talking about the relative adoption of 1090ES and UAT vs older assumptions that it would be largely UAT at lower-altitudes, and that is not what appears to be happening. And UAT receiver technology allows FIS-B data display for weather and TFRs etc. which is a nice benefit and nobody will want that taken away.

I don't understand why you think existing PowerFLARM devices are related to UAT. The only ADS-B thing a PowerFLARM can do is receive 190ES In, and only that direct from the 1090ES Out aircraft. They come out of Europe were there is no UAT and are completely incompatible with UAT. If UAT never existed PowerFLARM would be *more* useful in the USA because you would see all ADS-B Out traffic. PowerFLARM does not transmit on UAT, can't see UAT, and can't receive ADS-R relay of UAT traffic (even if you have a suitable ADS-B Out system to cause your glider to become an ADS-R client).