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US 5,209,430 AGranted
Helicopter low-speed yaw control
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsJohn C. Wilson, Cynthia A. Crowell, Henry L. Kelley
Life of this patent
Estimating the term…
Abstract
A system for improving yaw control at low speeds consists of one strake placed on the upper portion of the fuselage facing the retreating rotor blade and another strake placed on the lower portion of the fuselage facing the advancing rotor blade. These strakes spoil the airflow on the helicopter tail boom during hover, low speed flight and right or left sidewards flight so that less side thrust is required from the tail rotor.
Claims12
A helicopter yaw control system comprising:
- a helicopter;
- said helicopter having a main rotor attached thereto;
- said helicopter having a fuselage extending rearward through rotor downwash;
- helicopter yaw control means consisting of a combination of exactly two strake devices arranged asymmetrically about the fuselage, the combination including an upper strake being located above a lower strake, the upper strake being located along the side of the fuselage which faces the retreating rotor blade and the lower strake being located along the side of the fuselage which faces the advancing rotor blade;
- and
- supplemental control means to assist in controlling main rotor torque.
3 more elements
Dependencies are inferred from the claim text.