Well found out the "almost" hard way that putting your p3p into the truck and driving a mile to a new location will wreak havoc on your compass calibration, never powered down and figured I'd be fine. I got about 80ft up and got a compass error message and the drone started spiralling down to earth, switched over to Atti mode and it snapped back to life and I was able to land, performed a fresh cal on the compass and all was well after that. I would have been bummed out if I turned my 3 day old phantom into a lawn dart.