Copter circles in loiter mode to crash

I found a problem with my new octa (3.0.1-rc1) to circle counter-clockwise in loiter mode. It circles increasing radius and stops to hold altitude.
I experienced this problem with my previous octa (2.9.1b) sometimes, but switching to and flying in stabilize mode for some time solved problem. Also this issue appeared only in loiter mode. All automatic modes worked perfectly.
My new copter is much heavier and is built to carry big camera, also its CG is lower. It’s powerful enough to take off at about 45-50% throttle.
I cannot make it perform stable loiter. I’ve read declination issues, but why it doesn’t hold altitude doing that circles having enough power? May be there is software error migrated from previous versions?
Any ideas?


Hi I also got that “toilet bowl” when in loiter before. I think the problem is that the magnetic sensor needs callibration, try to enable the compass learning parameter for a while. It can also be that you have to setup compass-motor compensation, more here, you can see his quad is toilet bowling in the video: … clination/