To recap:
I asked you to falsify my presented scenario of straight non-slipping flight, as you claim it cannot happen. This scenario builds on the horizontal component of stabiliser force. Your reply was:
Where are you getting that "horizontal force at the stabiliser" if it is not being generated by the very sideslip you think you have made go away.
In other words, you claimed there’s no horizontal force generated at the stab without sideslip. In return, I point out that if you deflect the rudder there will most certainly be a horizontal force even though there’s no sideslip.
Then you counter (?) with:
Consider straight and level balanced non asymmetric flight. Rudder is centre. Now apply a little rudder and the aicraft must yaw into a sideslip as a direct result of the sideforce you have just applied to the tail by the rudder/fin force. Any change to rudder angle under any circumstances changes the side force.
My good man! I do believe you are contradicting yourself slightly!
And this leaves me with my example of straight, non-slipping flight with asymmetrical thrust still unfalsified. And while it is unfalsified, there is non-slipping asymmetrical straight flight.
Regards,
Fred, patiently waiting
(BTW, my definition of slip, for the purpose of this discussion, would be “the angle between the projections of the aircraft x axis and the flight path vector on the horizontal plane”)