I flew my 3DR-B tonight in startlingly windless conditions. It was the first time I've really tried to test Loiter. I got the quad into a nice stable hover (it was hovering practically dead still in these conditions with no control input at all) and flipped to LOITER. It did a pretty good job of staying in place but started to sort of orbit around the spot it started in. These orbits slowly got wider, to the point where I got uncomfortable and switched back to stabilize, though it took a minute or so.
Is this normal? Do I need to tune my LOITER PID? I noticed that the simulator has a default LOITER D of 0 while the default for Arducopter is 0.4. Changing the sim to 0.4 seemed to make it oscillate more in windless conditions, so maybe the answer is to change my D to 0? But will that negatively effect performance in windy conditions?
Here's my log from tonight: 2012-07-09%2023-07%202.log
Thanks for any advice.