Helicopter anti-torque system using fuselage strakes
First Claim
1. A helicopter torque control system comprising:
- a helicopter;
said helicopter having a main rotor attached thereto;
said helicopter having a fuselage extending rearward through rotor downwash;
helicopter torque control means consisting of a combination of two strake devices, the upper strake being located above the lower strake and both strake devices located only along the side of said fuselage which faces the approaching main rotor blade, for altering rotor downwash, thereby altering lateral aerodynamic force of the fuselage so as to counter main rotor torque; and
supplemental control means to assist in controlling main rotor torque.
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Accused Products
Abstract
A helicopter 10 with a system for controlling mainrotor torque which reduces the power and size requirements of conventional anti-torque means. The torque countering forces are generated by disrupting the main rotor downwash flowing around the fuselage. The downward flow is separated from the fuselage surface 11 by strakes 16 and 17 positioned at specified locations on the fuselage 11. These locations are determined by the particular helicopter wash pattern and fuselage configuration, generally being located 30° before top dead center 21 and 30° from bottom dead center 22 on the fuselage side to which the main rotor blade 12 approaches during rotation. The strakes 16 and 17 extend along the fuselage 11 from the cabin section 18 to the aft end and can be continuous or separated for aerodynamic surfaces such as a horizontal stabilizer 15.
47 Citations
19 Claims
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1. A helicopter torque control system comprising:
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a helicopter; said helicopter having a main rotor attached thereto; said helicopter having a fuselage extending rearward through rotor downwash; helicopter torque control means consisting of a combination of two strake devices, the upper strake being located above the lower strake and both strake devices located only along the side of said fuselage which faces the approaching main rotor blade, for altering rotor downwash, thereby altering lateral aerodynamic force of the fuselage so as to counter main rotor torque; and supplemental control means to assist in controlling main rotor torque. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A helicopter torque control system comprising a helicopter;
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said helicopter having a main rotor blade attached thereto; said helicopter having a fuselage extending rearward through rotor downwash; said helicopter having a horizontal stabilizer; helicopter torque control means consisting of a combination of two strake devices, the upper strake being located above the lower strake and both strake devices located only along the side of said fuselage which faces the approaching main rotor blade, said upper and lower strakes being individually segmented into parts with one part extending from the cabin area of the fuselage to the horizontal stabilizer and the other part extending from the horizontal stabilizer to the aft end of the fuselage boom, thereby altering rotor downwash and altering lateral aerodynamic force on the fuselage so as to counter main rotor torque; and supplemental control means to assist in controlling main rotor torque. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification