Mike Schumann wrote on 11/9/2020 9:46 AM:
On Sunday, November 8, 2020 at 4:49:34 PM UTC-6, Andrzej Kobus wrote:
On Sunday, November 8, 2020 at 12:34:34 PM UTC-5, Mike Schumann wrote:
....
The only reliable way to determine the 1090ES vs UAT equipage is to get this data from the FAA. They have all of this data, given that everyone equipped with ADS-B has to run an ADS-B performance report, which requires the pilot to identify not only what frequency the ADS-B OUT is on, but also the manufacturer of the ADS-B transmitter and GPS source.

When you look at the low cost UAT ADS-B options available from Garmin, uAvionix, and others, I would be willing to wager that a very significant proportion of the GA fleet is UAT equipped.
Well, I went back to look at configuration of some stations. It is true, many don't support UAT, so we simply don't know what the true number might be.

I just got the following ADS-B OUT statistics from the FAA as of 11/1/20:

1090ES - 103,871
UAT - 29,325
DUAL - 1,197

As you can see almost 30% of the A/C in the US are UAT equipped. Since all aircraft that operate above 18K ft need to be 1090ES equipped, the percentage of single engine piston A/C that are potential threats to gliders is even higher than that.

There are about about 8000 commercial aircraft. That suggests about 120,000 GA aircraft are
ADS-B equipped. There are about 220,000 GA aircraft registered in the US, suggesting 100,000
are not equipped with ADS-B. If true, our biggest danger is that 100,000, not the UAT equipped
ones. It may not be that bad, as Flarm will pick up any of those with transponders.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1