I believe this is a true statement, although no one, to my knowledge, has claimed their non-TSO'd GPS meets the IFR TSO's performance standards.
...
The manufacturer (or other knowledgeable person?) must state that it meets all of the TSO "performance standards", even if it lacks the actual TSO.
Meeting TSO standards for an IFR GPS also means meeting the data integrity standards for the nav database. And really, by the time a company has gone through the effort to meet the performance standards, they might as well get the actual TSO and use that to broaden their sales base.
What's really interesting is that, for
all aircraft, at least the ADS-B Out requirement is "meets the performance standards of". If you have a Cessna, you aren't required to have a TSO'ed ADS-B box.
However, you still have to get that onto the aircraft in an approved manner--and by the rules in Part 21, that means it either needs a TSO, or it has to be approved in type data (TC or STC).
The FAA did issue guidance a few years ago that allows you to install ADS-B on a 337 without further approval, but one of the conditions is that the unit is TSO'ed. And so, for all practical purposes, certified aircraft are limited to TSO'ed equipment, because getting approval for non-TSO'ed boxes would cost more than just buying the approved stuff.
So, you could use a non-TSO'ed unit on a certified airplane
if you can manage to get an actual STC to do so. And with Dynon now moving forward on STCs, I'd expect to see their ADS-B Out solution included in the Skyview HDX STC.
