if you did not turn on arcade flight model, the helicopter will constantly pitch up and roll to right due to dissymmetry of lift and gyroscopic precession.
I have turned on the Arcade flight model. Like sometimes, during startup, The heli tilts to one side. I then yank the Cyclic in the opposite direction. But then it is too much and it tilts to the other side. And again. And again. Until the cycle reaches its vicious end, i.e, a vicious crash.
