This evening I got a crude (but surprisingly effective) autopilot working in Flightgear, and also cracked open my receiver and waved an oscilloscope at it. The autopilot is a separate ruby script which uses the Flightgear httpd interface to read and write values which control the plane. The plane managed to stay up in the air, despite me selecting heavy turbulence. But, to quote Susan, “I wouldn’t like to be a passenger in that plane!”. So, next I need to add a bit more complexity to the autopilot (technical version: my pid controller needs some id).