Hi,   I made a plugin for XPlane, so i can simulate my UAV code before i buy/make any hardware. Stabilisation, "pathfinding" works great but Im stuck with my AHRS. I implemented a basic Kalman Filter, which works great so far for estimating roll and yaw with gyros, accelerometers and GPS.  However pich gives me some trouble. Altough William Premerlani wrote in his DCMDraft2 (page 24) that the for…