Originally Posted by
WideScreen
Intriguing, that an "after-market" Mode-C device in a war-bird would deliver lower quality altitude information, than a similar one in a 30-years old C172. Flying a war-bird without a proper functioning pitot-static system doesn't look that wise to me, either. It's pretty basic stuff, nothing special. And the video shows, the calibration differs a little between the P-63 and the P-51, see my earlier posting, though not that much, that it would be worrying. I've flown C172s, obviously significantly more out of calibration, already at 1500 ft AGND.
Feel free to correct me if I am wrong, but I believe the data being discussed is ADS-B data from ADS-B Exchange. ADS-B does not rely on airspeed or altitude data generated by the aircraft, but rather reports on WAAS GPS generated data.