I'm wanting to smooth out the autopilot when in a HDG-NAV intercept mode.The scenerio is that when within 5nm of the desired GPS Track (DTK), the ap will command an aileron roll towards the DTK, and when within 2.5 nm control will be handed over to NAV/GPSS (GPS Steering mode).Using the algorithim below, up to 90

Thanks for playing anyway. I found help elsewhere and managed to developed a function that works a treat...

Sorry, was over my head.Patrick

>Sorry, was over my head.No problem. All I wound up doing was adapting a function to calculate the "entry point" for a turn to GPSS based on ground speed and angle of intercept.Once at the calculated DistanceToTurn, the ap will command a shallow aileron roll left or right based on the sign of the entry angle: negative angle means turn left, positive angle means turn right.What happens is the a/c will track a parabolic turn rather than a constant rate turn, sort of like an easement on railroad tracks before a curve... ;)A picture is worth a thousand words. The red track represents what the default NAV+GPS does. The green line represents what my PID Nav+GPSS controller code will do:http://img513.imageshack.us/img513/1181/in...ptanglesby0.jpg