Abstract: A rotary airscrew having a central hub with coaxial first and second counter-rotating drive shafts, a first set of a plurality of non-lift blades connected to the first drive shaft for rotation to be rotated for moving air therewith, a second set of a plurality of primary airfoil blades connected to the second drive shaft, to be rotated counter to the rotation direction of the plurality of non-lift blades, and spaced apart from the non-lift blades with a small clearance distance to allow non-contacting counter-rotation, and a ring for supporting the first and second sets of blades with a small clearance distance between the ends as they are rotated.