Patent ID: 8840058

Claim:
A rotary aircraft, comprising: a fuselage; an engine carried by the fuselage; a main rotor rotatably attached to the engine; and a tail boom attached to and extending from the fuselage, the tail boom having: a body having a first side surface and an opposing second side surface, the first side surface being contoured to act as a pressure surface of an airfoil and the second side surface being contoured to act as a suction surface of an airfoil; a leading edge; and a trailing edge, having: a rounded corner; and a sharp edge; wherein both the first surface and the second surface extend from the leading edge to the trailing edge; wherein the rounded corner joins the second surface to the trailing edge; wherein the sharp edge joins the first surface to the trailing edge; and wherein the sharp edge reduces drag of the tail boom during a sideward flight motion of the aircraft; wherein the engine rotates the main rotor, thereby creating rotorwash and a fuselage torque; wherein the rotorwash flows around the first side surface and the second side surface of the tail boom, resulting in a high-pressure region forming near the first side surface and resulting in a low-pressure region forming near the second side surface; wherein the pressure difference between the high-pressure region and the low-pressure region causes the tail boom to move towards the low-pressure region, resulting in a lateral force opposing the fuselage torque; and wherein the tail boom is rotatably attached to the fuselage.