US 11,447,243 B2Granted

Helicopter with anti-torque system, related kit and methods

AssigneeBLR Aerospace, L.L.C.

InventorsMichael Carpenter, Daniel A. Smith

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Abstract

A strake may extend along a portion of an approaching side of a tail boom of a helicopter. A number of vortex generators (VGs) may extend along a portion of a retreating side of the tail boom. For tail booms with circular cross sections, the strake and the VGs are positioned between approximately 5 and 15 degrees below a horizontal plane of the tail boom when viewed end on, on respective sides of the tail boom. For tail booms with non-circular cross sections, the strake and the VGs is positioned between approximately 5 and 15 degrees above a location where a change in curvature is greatest (e.g., where flow separation would otherwise occur) on a bottom half of the tail boom when viewed end on, on respective sides of the tail boom. A fairing may be located on the retreating side on the upper half of the tail boom, to create an asymmetric profile.

Claims20

Dependent claims

A helicopter, comprising:

a fuselage;
a main rotor coupled to the fuselage and that in operation rotates in a first rotational direction with respect to the fuselage;
a tail boom that extends rearwardly of the fuselage, the tail boom having an approaching side and a retreating side, the approaching side being a side of the tail boom that the main rotor approaches when rotating in the first rotational direction, the retreating side being a side of the tail boom that the main rotor retreats from when rotating in the first rotational direction, the retreating side opposite the approaching side across a width of the tail boom, the approaching side of the tail boom having a constant radius of curvature about a centerline, and the tail boom having an upper half, a lower a half and a horizontal plane that extends between the upper half and the lower half of the tail boom;
a strake that extends outwardly from the approaching side of the tail boom, the strake positioned below the horizontal plane of the tail boom at an angle of from approximately 5 degrees to 15 degrees, the angle measured between the horizontal plane and an axis that extends from the centerline to the strake;
and
at least one vortex generator that extends outwardly from the retreating side of the tail boom, the at least one vortex generator positioned below the horizontal plane of the tail boom at an angle of from approximately 5 degrees to 15 degrees, the angle measured between the horizontal plane and an axis that extends from the centerline to the at least one vortex generator.

3 more elements

A method of manufacturing a helicopter having a fuselage, a main rotor coupled to the fuselage and that in operation rotates in a first rotational direction with respect to the fuselage, and a tail boom that extends rearwardly of the fuselage, the tail boom having an approaching side and a retreating side, the approaching side being a side of the tail boom that the main rotor approaches when rotating in the first rotational direction, the retreating side being a side of the tail boom that the main rotor retreats from when rotating in the first rotational direction, the retreating side opposite the approaching side across a width of the tail boom, the approaching side of the tail boom having a constant radius of curvature about a centerline, and the tail boom having an upper half, a lower a half, and a horizontal plane that extends between the upper half and the lower half of the tail boom, the method comprising:

positioning a strake to extend outwardly from the approaching side of the tail boom at a strake position, the strake position located below the horizontal plane of the tail boom at an angle of from approximately 5 degrees to 15 degrees, the angle measured between the horizontal plane and an axis that extends from the centerline to the strake position;
fixing the strake to the approaching side of the tail boom at the strake position
positioning at least one vortex generator to extend outwardly from the retreating side of the tail boom at a vortex generator position, the at least one vortex generator position located below the horizontal plane of the tail boom at an angle of from approximately 5 degrees to 15 degrees, the angle measured between the horizontal plane and an axis that extends from the centerline to the vortex generator position;
and
fixing the at least one vortex generator to the retreating side of the tail boom at the vortex generator position.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/372,243Filed 1 Apr 2019 · continuation
Priority: 2 Jul 2015
Published: US 2019/0225331 A125 Jul 2019
Granted: 20 Sep 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B64C 27/82
Rotorcraft; Rotors peculiar thereto: characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor…
B64C 7/00
Structures or fairings not otherwise provided for
B64C 23/06
Influencing air flow over aircraft surfaces, not otherwise provided for: by generating vortices
B64C 2027/8263
Characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of…:…

Family

Application62/188,305Us provisional application · filed 2 Jul 2015
Application15/197,329Parent of this continuation · filed 29 Jun 2016
US 2019/0225331 A1Pre-grant publication · published 25 Jul 2019
US 10,279,899 B2Parent of this continuation
US 2017/0001722 A1Published application
US 11,447,243 B2This patent

From the US filing history. Foreign family members aren’t listed.