Flywheel Rotor/Wing Makes Stopped Rotor Aircraft Practical

The Flywheel Rotor/Wing (FRW) aircraft is the final evolution to a practical Stopped Rotor aircraft. It can Vertically Takeoff or Land (VTOL) like a helicopter. For high-speed forward flight, the two rotating rotor blades are quickly stopped (in approximately 1/2 sec.), and then serve as fixed wings. Rapid spin-up or stopping of rotor blades is accomplished by coupling them to a small rotating flywheel. The flywheel imparts angular kinetic energy directly to the blades without any undue torque to the fuselage. A variable pitch ducted fan provides forward thrust during fixed wing flight, and transfers all available power, through a conventional transmission, to main rotor blades during rotary wing flight. Objectives and material covered in this paper include: (1) Introduction to FRW design and comparison to other aircraft, (2) Presentation of FRW analytical results, predicting simple and reliable conversion between flight modes, (3) Proposal for fielding a FRW flight demonstrator who’s design and scale allow it to immediately become an effective Unmanned Air Vehicle (UAV) once flight proven, (4) Description of a family of FRW aircraft, ranging in size from Tactical UAVs to Hercules C-130 sized troop-cargo transports, and (5) Conclusions.