I was flying yesterday after a nice cold front hit with all its associated winds. I was cruising at 1,000 feet and noticed my TAS was 75 but GS was 130! The Dynon Skyview showed an almost direct tailwind at 55. My hand held GPS verified the GS as 130. I did a 180 at the same altitude. Still 75 TAS but the GS was now 117 with the Skyview again showing a direct tailwind. Today I check my pitot and static lines. The rubber was so brittle the tubing kept snapping apart at 6" intervals.

So I have learned to replace those lines at the 5 year point (just as I do with the rubber parts on my Rotax). And I am guessing the Dynon software is programmed to look at TAS, get GS from the onboard GPS and using math and geometry arrive at a wind component and velocity. Just my two cents. Be safe.