I don't have a significant number of flights on my P3A but a couple of times when I'm firing things up my iPad wants to do a compass calibration and it is confusing me a little. The iPad does not have any internet connectivity, Yesterday when it did this I had compass errors on the AC and it went from P-GPS to ATTI mode and because of the wind started to drift off. Is there any correlation here? Somewhat PO'd with the AC errors as I just returned one that was having significant compass errors.