In my opinion there is no dissymmetry of lift at twelve and six o’clock so the blade is in its neutral position in relation to the spindle as it would be in a vertical descent with no forward airspeed.
With an anticlockwise turning as viewed from above at approximately three o’clock the blade has reached its maximum distance above its neutral position.
At approximately nine o’clock the blade has reached its maximum distance below the neutral position.
Vance, my understanding is that up/down
velocity changes the angle of attack because it changes the apparent direction of airflow. If you are moving down, the air seems to come from a bit lower position, while if you are moving upward, the air seems to come from a higher position. But all this depends on motion/velocity, NOT on position. Merely having a blade high or low does nothing; it is the velocity that makes the angle appear to change, because it adds an extra component to the relative wind. You get a compensating effect only from speed, not from height.
At the highest position, you momentarily have no up/down velocity, for the instant between climbing and descending. That means you have no angle of attack effect at that time. This is what happens at 12:00. You are at max height, neither moving up or down, and doing nothing to angle of attack, at the same time that you have no dissymmetry of lift and don't need any compensation.
Likewise, at 6:00, you are at the lowest point, with no up/down flapping velocity, for the instant between descending and climbing. With no flapping motion, you have no effect on angle of attack, and don't need any, because there is no dissymmetry.
At the 3:00 position, you have the maximum upward velocity, for maximum angle of attack effect, but you are not yet at the top of the climbing motion (you're still moving upward quickly). As rotation continues, you lose upward velocity, eventually hitting zero when you reach 12:00.
Thus , at 3:00, the blade has its maximum upward
velocity, but has not yet reached maximum
displacement (which happens at 12).
One addtional thought: if the blade was highest at 3:00, the disc would appear to tilt left; with max height at 12:00, it appears to tilt back.
I feel the most important takeaway for a gyroplane pilot to understand is; no pilot input is required to manage dissymmetry of lift and the retreating will likely stall first because it is at a higher angle of attack than the advancing blade.
No argument there!