I had similar on my first check flight.Â* In 3 or so hours of so of
flying I had a momentary GPS drop out and that caused the failure. I
repeated the flight in an area outside the GPS interference testing area
and got a perfect score.Â* I don't worry about it any more.Â* OBTW, I just
had a perfect 2-year transponder ground check.

On 6/8/2019 8:04 AM, Sandy Coleman wrote:
On Saturday, June 8, 2019 at 7:36:22 AM UTC-6, wrote:
I recently installed Trig-22, TN-72 in my glider and passed ground test. After 3 competition days I pulled free FAA reports- two days are fine and in one day I have red value in NIC column (integrity and accuracy) of 0.41% fail. PAPR user guide does not say much what can be cause of this fail. Is anyone experienced willing to help evaluate failed report? Should I turn off TN-72 on my panel even only 0,42% in one flight was faulty(red) report out of 3 flights of 13 hours? Thank you. pavel
Search for "transponder 2 year check". Look at the May 9 posts. The answer is there as well as an offer to evaluate the report. One thing PAPR cannot measure is power out at the antenna.

Please do not turn off your GPS for the transponder! You may become invisible to aircraft with ADS-B in.

--
Dan, 5J