On Thursday, December 17, 2015 at 12:46:45 PM UTC-5, Andrew Ainslie wrote:
Apparently it can't just be any non TSO'ed GPS to be fully compliant. A few months ago the FAA opened up a new category whereby "equivalent" units could be used in Experimental, and this device of Garmin's is the first to fit this new niche. Hopefully others are following, including Trig. But agreed, it's ridiculous that we can't just use on of the other GPS's floating around our cockpits to give the TT22 the required information. Anything WAAS (hell, actually anything at all) is way better than either radar or nothing at all. Part of the frustration is that without ADS-B we get no input. It would be so nice to know where the power guys with mode C are relative to us. The FAA definitely needs someone like JC to explain why their strategy of "forcing" us to get ADS-B out in order to get in is deeply flawed, and the requirements to either spend over $3000 or be blind is equally dumb... But that ain't going to happen. In the interim, I'm going to keep hoping that a reasonable solution shows up.

There is an intermediate solution whereby you can hook up a non compliant unit but if you properly declare the signal, I don't think you get ADSB in but I don't recall the exact details. I'd prefer full compliance but I think it might be time to play with that option over winter.

The next problem, of course, is to get a transponder shop to help you get anything done. They are very leery of helping with experimental planes and non TSO'd options. My local guy just told me that he'd no longer do my transponder certification, even though the TT22 is a TSO'd unit and he installed it a year ago - he claims the FAA does not allow him to work on experimental. Sounds like baloney but not much I can do about it if he doesn't want to do the work.

(In the US, 'Your tax dollars at work', or not, your choice....).

I'm only commenting on my limited knowledge of how some of this works, I also agree some of it "sorta sucks"...... but what do I know....