I have the problem, that my copter makes a sky fall when I switch in loiter mode.
The Copter is a APM 2.5 with the 3.1 software. The weight is 1800gr. or with cam 2.300 gr… I use 15" 5.5 props on 300W 370KV motors, LEA 6H GPS from HK.
In stabilize mode the copter flyes realy good, sometimes a small wobble in. I can fly the copter complete in altitude hold and it flyes very stable. But, as soon I switch to loiter, the copter fall fall out of the sky.