I've never had a compass error, 30 flights or so. I have a new iPad mini 2 + cellular and a trackimo 100 I just added. I was flying in a farm field, not near any metal and pockets empty. I was about 4000' out when I got a compass error. (Showed 1490-1510) I was able to fly it back but when I was 15' feet away it was still flipping back and forth between compass error and GPS. When I had a mini 2 wifi I flew on airplane mode. Now I fly Cellular data only. Any idea of the issues? Checking out healthy drones now.