On Monday, November 25, 2019 at 10:06:27 PM UTC-8, Darryl Ramm wrote:

"....the system must be capable of switching to ground mode".

Hi Darryl, thanks for providing the relevant regulation. I find it very unclear, but now at least I know the regulation behind this discussion. Personally, I would say that since my glider can't fly without me in the cockpit, I am an essential part of the system, and as such, I will manually turn the adsb system off when I'm on the ground. So I'm doing that in my experimental glider, with my self-installed TT22/TN72. My installation has passed the airborne adsb check that ATC provides, and I showed that report on my last condition inspection, although I was not asked to. I did also buy a squat switch on ebay for $12, but decided not to install it, since I worried that a small leak would upset my flight computer, which is vital when flying here in the west.