In an attempt to make a flight plan that will make it over a mountain peak and land in a valley, I have defined the following plan to command Ardupilot to loiter to a certain high altitude, traverse to another waypoint, then loiter safely down to another low altitude:

xplane_high_alt.h

#define WP_RADIUS…

After some decent results described in my previous post regarding PID tuning for high winds: http://www.diydrones.com/profiles/blogs/pid-tuning-for-high-winds, I wanted to see what it would take to get the best possible flight path with the least amount of flight planning possible. The end result was a three waypoint 90degree corner, as shown below.

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After a grossly failed attempt at fully automatic landing due to mild winds (luckily no damage), I decided to go back to the simulator and see what PID tuning is required to handle the harshest flyable wind conditions that I could throw at Ardupilot. Because I fly in the mountains and I'm interested in fully automatic take-off and landings, path following needs to be as accurate as possible.

Xplane settings:

Plane: Radio controlled PT60

Weather: Wind: 25kts at…