I have read about Curtis Olson's use of flightgear for UAV development, but didn't see any applications to download to get started working on an autopilot with. So I've started on my own: http://code.google.com/p/binarymillenium/wiki/FlightGear
There's not much to it currently, it just demonstrates that I can receive vehicle state information through the native-fdm udp interface. Read more…