Contra rotating propeller

Aircraft equipped with contra-rotating propellers, also referred to as CRP,[1] coaxial contra-rotating propellers, or high-speed propellers, apply the maximum power of usually a single piston or turboprop engine to drive two coaxial propellers in contra-rotation (rotation about the same axis in opposite directions). Two propellers are arranged one behind the other, and power is transferred from the engine via a planetary gear or spur gear transmission.