Originally Posted by
EGOSEC135Juno
This long running thread is good. But only Thomas coupling seems to have the answer. It’s all to do with differential flap back. While there is no relative V change made by raising and lowering the collective, there is a difference in percentage change of alpha. On the advancing side, a lever raise changes alpha by far more in percentage terms than on the retreating side, because the advancing side has a lower alpha to begin with. Across the fore/aft axis, when phase lag is applied, the disk climbs more on the advancing side than the retreating side, causing a ‘flapback’ effect leaving the disk higher at the front. The opposite is true for a lowering of the lever - lever down, ‘flap forward’, disk lower at the front.
I think I said that in post #54