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. The generator may be used to charge a battery during autorotation or descending. 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.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. A bulkhead is positioned rearward from the cockpit and oriented perpendicular to a longitudinal axis of the airframe. A tailboom and engine are mounted to the airframe by means of the bulkhead having the engine mounted between the tailboom and a lower edge of the bulkhead. Landing gear may mount to the bulkhead proximate a lower edge thereof. Systems and methods redistribute fuel among laterally, vertically, and longitudinally opposed fuel tanks to maintain a center of gravity in a dynamically stable position.

Abstract: A fairing system may be assembled about a rotor of a rotorcraft to present an aerodynamically quasi-static region that rotates in an airstream, as well as certain extensions that sweep through the airstream as the rotor hub passes through the air. A spherical interface between the extensions on the rotor hub fairing and the base or root portion of each blade fairing provides three degrees of freedom permitting lead-lag, flapping, and blade pitch pivoting in the blade, while still maintaining an aerodynamic profile that will minimize drag.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. A bulkhead is positioned rearward from the cockpit and oriented perpendicular to a longitudinal axis of the airframe. A tailboom and engine are mounted to the airframe by means of the bulkhead having the engine mounted between the tailboom and a lower edge of the bulkhead. Landing gear may mount to the bulkhead proximate a lower edge thereof. Systems and methods redistribute fuel among laterally, vertically, and longitudinally opposed fuel tanks to maintain a center of gravity in a dynamically stable position.

Abstract: A fairing system may be assembled about a rotor of a rotorcraft to present an aerodynamically quasi-static region that rotates in an airstream, as well as certain extensions that sweep through the airstream as the rotor hub passes through the air. A spherical interface between the extensions on the rotor hub fairing and the base or root portion of each blade fairing provides three degrees of freedom permitting lead-lag, flapping, and blade pitch pivoting in the blade, while still maintaining an aerodynamic profile that will minimize drag.