Abstract: A rotorcraft is disclosed. The rotorcraft may include a rotor having at least one tip nozzle, a compressor having an outlet for compressed air, and a network of conduits connecting the outlet of the compressor with the tip nozzle. In operation, the compressor may deliver a flow of compressed air to the tip nozzle. As the flow of compressed air exits the at least one tip nozzle, it may cause rotation of the rotor. This rotation may prerotate the rotor and shorten the take off distance required by the rotorcraft. Take off of the rotorcraft may be accomplished without ever adding fuel to the flow of compressed air to the tip nozzle.

Abstract: Apparatus and methods for controlling yaw of a rotorcraft in the event of one or both of low airspeed and engine failure are disclosed. A yaw propulsion provides a yaw moment at low speeds. The yaw propulsion device may be an air jet or a fan. A pneumatic fan may be driven by compressed air released into a channel surrounding an outer portion of the fan. The fan may be driven by hydraulic power. Power for the yaw propulsion device and other system may be provided by a hydraulic pump and/or generator engaging the rotor. Low speed yaw control may be provided by auxiliary rudders positioned within the stream tube of a prop. The auxiliary rudders may one or both of fold down and disengage from rudder controls when not in use.