Good Morning Lu,
Vorticey, is quite right, I agree with his statement about the need to pull slightly right cyclic to stay on a straight heading, and I have read most of your past posts regarding this item, whilst some posters have argued with your theory I do believe the majority have learned quite a lot from the past threads. However not wishing to start an encyclopeadic type of answer , what would happen if Frank R removed this 18deg P/C situation and followed what you see as the correct angle, would this have some detrimental effect to the Robinson Teetering head and pitch change controls, or is it a whole new engineering problem of design and re-engineering of all the parts including the blade/horns
My Regards