This rocket-engined prototype, developed for the United States Navy, was designed so that at need it could be used by 'strapping-on'. The rotor was driven by two liquid-fuel rockets. Nitrogen gas under pressure forced hydrogen peroxide stored in two tanks through the hub and blades. At the tip of the latter, the hydrogen peroxide came into contact with a catalyst, and the resultant thrust was sufficient to turn the blades at more than 500 r.p.m. No hydraulic system, starter or electricity was used in the "Pinwheel".

Originally equipped with Reaction Motors XLR 32 RM rocket units of the same type as used in the Kellett HR-15, the RH-1 now has rockets developed by Rotor-Craft itself, which are throttle-controlled, and thus differ from previous helicopters of this type, in which the power setting could be only 'on' or 'off'.

P.Lambermont "Helicopters and Autogyros of the World", 1958