I have went through multiple video tutorials to fix horizon tilt. Gimbal roll, IMU cal on level surface, on iOS 8.3, deleted the go app and reinstall, different settings. The only other thing I can think of is downgrading the firmware to 1.3.2. To see if that helps. Starting to think it mechanical failure. Any other ideas or suggestions? Trying to fly until winter, then I'll send it in to DJI? Anyone ever heard of a bad compass throwing off the gimbal? I added a trackimo and my p3 has not been right since. When it was mounted I put I right over the compass by accident. Since I have removed the trackimo and still getting weird readings at times. I does fly ok, just bad horizon tilt.