[Dual G3X touch, GTN 650Xi, GMC 307, GMU 11, some other stuff...]
In flight, AP set to "TRK" mode via the PFD AP status bar & on screen menu. HDG knob used to select TRK course. Selected TRK selected is shown on the PFD, the GTN Xi active navigation screen.
After the flight, I downloaded the .CSV log file and noticed a discrepancy between what I had selected for TRK and what was shown in the log file -- exactly 4° off to the right; e.g. TRK selected was 210°, log showed 214°. TRK was 320° log showed 324°, TRK was 080°, log showed 084° and so on.
Here's where gets interesting, FlightAware's track log of the flights also show the 4° discrepancy, so the ADS-B is also sending out the "wrong" info. It's not winds aloft -- as the deviation is ALWAYS to the right; I was flying 3 leg patterns to determine TAS error.
Anyone know what the G3X "GPS Ground Track (deg), TRK" parameter is, where it comes from, and why it would be entered into the log 4° right of what was displayed EVERYWHERE else?
In flight, AP set to "TRK" mode via the PFD AP status bar & on screen menu. HDG knob used to select TRK course. Selected TRK selected is shown on the PFD, the GTN Xi active navigation screen.
After the flight, I downloaded the .CSV log file and noticed a discrepancy between what I had selected for TRK and what was shown in the log file -- exactly 4° off to the right; e.g. TRK selected was 210°, log showed 214°. TRK was 320° log showed 324°, TRK was 080°, log showed 084° and so on.
Here's where gets interesting, FlightAware's track log of the flights also show the 4° discrepancy, so the ADS-B is also sending out the "wrong" info. It's not winds aloft -- as the deviation is ALWAYS to the right; I was flying 3 leg patterns to determine TAS error.
Anyone know what the G3X "GPS Ground Track (deg), TRK" parameter is, where it comes from, and why it would be entered into the log 4° right of what was displayed EVERYWHERE else?