Originally Posted by
Ascend Charlie
You might find that the lift is constant all the way around. If you suddenly got more lift when the blades are fore/aft, the vertical vibration would be awful.
The retreating blade tries its hardest to create enough lift, battling the wind from behind.. The advancing blade has to throw away all that beautiful lift it gets from moving into the extra airflow. The only place where the fight is equal is fore/aft.
That comment was based on re-collection reading Ray Prouty's "helicopter aerodynamics", I guess the retreating blade struggling and advancing blade throwing away unused lift is sub-optimal. That makes the fore/aft aerodynamic situation better and potentially providing more lift. "the vertical vibration would be awful" it is awful, that is why we need so much rubber absorption at the main rotor transmission. Also let us not forget that the blades themselves are absorbing a lot of vertical vibration.