So basically your argument is based on the 'evidence' that'MajorTomskiright andthe recognised experts in the field of propeller propulsion are all wrong'....... Sorry if i don't find that a convincing argument. It's the case that the burden of evidencemust laywith the person trying to overturn accepted wisdom, so you need to come up with proof that the experts are all wrong, not just rhetoric.

As for your diagrams.. #2 is how it is (though the spiral angle is massiveness exaggerated, it's more likely to be only a couple of degrees). Of course the spiral slipstream effects any surface it encounters, including the wing and horizontal stab (both Hepperle and Stackhouse said so much in the quotes i included in my last post). The effectof the interaction with all surfaces is,as you pointed out, to produce a rolling torque to the right butbear in mindthatthese surfaces don't take all the energy out of the slipstream so this right rolling torque will always be much less powerfulthat the left motor reaction torque produced directly by the engine, so the overall torque remains to the left.

You can see evidence of spiral slipstream in the design of stators in a EDF fan or in the compressor statorsin an axial flow turbine. As further proof there is the use of right thrust to trim aerobatic model in the up-line as discussed a few posts ago. In a vertical climb then there is no P-factor because the prop disk is perfectly perpendicular to the direction of travel. Also as you point out, torque would not produce a left yaw.. <u>So why is it that most if not all planes yaw left in a vertical climb unless right thrust is added?</u> (my latest aerobatic model needed 4.5Deg of right thrustto straighten the up-line)

Steve