Originally Posted by 172_driver
I guess only a diverging dutch roll (where the roll rates become greater by each oscillation) will finally result in a stall? When the wing is moving downwards the angle of attack will increase. Am I right in that sentence?
The downgoing wing does indeed experience an increase in angle of attack, and in theory, yes, if the Dutch roll oscillation were allowed to progress to a severe enough point then you could induce a local stall (starting at the tip, since the local velocity would be greatest). But it'd have to be a pretty gross Dutch Roll at that point, and I'm not sure you wouldn't see other handling non-linear behaviour (perhaps in yaw) before you reached that point. Even then, the first effect would simply be to reduce the Cl-p contribution a bit, since most of the wing flow would stay attached. To get to the point of actually seeing a "stall" that caused some form of autorotation would require huge roll rates.