wrote:
Couple questions, maybe Darryl you could take a shot at these.

Would there be a perceptible position error if one compared the reported
position from a PowerFlarm Core with a fully approved ADSB source.
Compare it to say the Trig TN70 unit. http://www.trig-avionics.com/tn70.html

If the reported position error is suitably small, what would be required
to show that the PowerFlarm Core meets the "performance requirements" to
be used as a NMEA source for ADSB out?

With many of us in the US installing PowerFlarm, there is some sense to
seeing if this device could get to the point, legally, of being used as a
source for a Trig transponder that is capable of ADSB out.


Mark

I already kind of covered this in another thread, there is absolutely no
way any standard consumer type GPS source (like used in PowerFLARM) can
meet the performance requirements of TSO-C145 or similar specs. The hard
part of those requirements is not so much positional accuracy they are
reliability and error detection. You cannot use any NEMA GPS to do this
(meet the 2020 carriage mandate requirements), there is not enough
reliability related data in the NEMA steam, suitable GPS' talk ARINC 429 or
'Aviation' serial format over RS-232.

Again, all this is why TSO-C199 is interesting as it specifically covers
using consumer GPS sources in ADS-B based anti-collision beacons. However
that TSO does not apply to the 2020 ADS-B out carriage mandate (which
gliders are exempt from). Read that TSO to get a flavor of what is
involved, it needs work from a vendor to show a GPS is suitable, not just
an end-user connecting up any old consumer GPS. One of the encouragements
for the FAA doing all this is... the careful and successful use of
consumer GPS technology in FLARM.