Mart, you said
"the seperation is constant"
Re Coaxial - Sikorsky ~ S-69 (XH-59) ABC
5. As the
phase angle is decreased, the clearance between the blade tips of the two rotors decreases. Minimum clearance occurs at the crossover of a retreating upper blade and the advancing lower blade on the left-hand side of the rotor disk. (Ref. Rotors articulated at the center of the mast have a phase angle of roughly 90º.)
1. The swashplate has an adjustable phase angle of 0º to 70º.
Opposed Lateral Cyclic:
1. Lift Offset: Differential displacement of the rotor thrust vectors can be controlled in two ways on the demonstrator aircraft: by introducing differential lateral cyclic (B1') through an independent control or by the variable phasing of the pilot inputs to the rotor (Г). Testing to date has concentrated on the use of variable phase angle.