I believe TCAS is based on ADS-B but requires a certified GPS input or the information is ignored by a receiving TCAS equipped aircraft, don't know why this is when was the last time your GPS was totally wrong, I think better a couple of false triggers than bumping into something, again I think the SE2 has a certified GPS so would trigger TCAS. Feeding a TRIG transponder with the GPS from a PAW, which is uncertified will not trigger TCAS. On a PAW a FLAM unit can be directly connected to it, so no ground support needed just more costs. Don't know if Flarm traffic will see you?
Other catch feeding a PAW into a transponder for a certified aircraft, the installation must be carried out by a certified engineer and signed off by them. On a permit aircraft can be fitted by you but the LAA do the signoff. Both need a flight check. So thinking about it a PAW with a mixture of ground support will tell of most things around you but with no transponder only other PAW equipped traffic will see you. With an SE2 only sees ADS-B traffic plus Flarm again I don't think it tells FLAM only traffic you are there, buts costs a little extra a year, but does tells all ADS-B traffic your position.
Now if PAW added ADS-B with a certified GPS that would be something. I think there so much computing power in a PAW they could add TCAS but the certification would be very expensive.
Last edited by horizon flyer; 12th December 2020 at 22:08.