I believe that very large twist is advantageous when acting as high-speed propellers. In addition, a very large twist (
Ideal Twist) is advantageous for a helicopter rotor when it is operating in hover or vertical flight. However, it is a disadvantage for a helicopter during forward flight. The PropRotor is always operating in axial remote velocity airflow therefore high twist is a plus.
However, it appears that a very large twist represents a problem when acting as rotor during fast vertical descent. This is because the whole rotor can stall at the same time.See
An early report on twist for proprotors suggested a smaller twist during hover of 26.6º, a larger twist of 44º for cruise, and a compromise of 36º.
I would question the validity of this, particularly when considering the 1x2, which has fore and aft PropRotors located on the centerline of the craft.
