Below is a very well done white paper on stability by Russel Williams
that addresses much of what we have been discussing.

The long and short of it in my opinion is that positive lateral
stability is present in GA airplanes and they will tend to recover from
the sideslip coupling. Your key point addresses potential disturbances
that can indeed exceed this recovery tendency.
I agree totally with you that such a disturbance can exceed positive
stability tendencies if strong enough.

I believe you will find this paper interesting and informational.


http--soar.wichita.edu-dspace-bitstream-10057-754-1-t05045.pdf.webloc



--
Dudley Henriques