A helicopter is described comprising: a tail boom; a fin projecting from the tail boom; and a tailplane arranged at the tail boom and transversal to the fin; at least one of the fin and the tailplane defining a first aerodynamic surface generating a first aerodynamic force; at least one first element transversal to the first aerodynamic surface; and a second aerodynamic surface generating a second aerodynamic force, connected to the first element, facing and spaced from the first aerodynamic surface; the second aerodynamic surface is spaced from the other of the fin and the tailplane.

A helicopter is described comprising a fuselage elongated along a first axis and extending between a nose and a tail boom; a tailplane with a pair of first aerodynamic surfaces elongated along a second axis; the first and second axis define a first plane; the helicopter comprises a pair of elements transversal to the first aerodynamic surfaces; and a pair of second aerodynamic surfaces generating respective second aerodynamic forces, connected to first elements, and facing and spaced from respective first aerodynamic surfaces; each second aerodynamic surface comprises one first root end connected to the respective said element, a second free end spaced from said tail boom, a first leading edge, a first trailing edge opposite to said first leading edge, a first chord at said first root end and a second chord at said second free end parallel to said first axis; the first and the second chord define a second plane tilted with respect to said first plane.

A wind turbine blade includes a trailing edge flap having a flap part protruding from the trailing edge on the pressure side of the blade. The flap part has a first section and a second section each having an upstream surface arranged to face an oncoming airflow in use. The first section extends from the trailing edge and has a proximal end and a distal end in cross-section. The proximal end is located at or near the trailing edge and the distal end is spaced apart from the trailing edge. The first section is oriented such that an obtuse angle is defined between the upstream surface of the first section and a plane that extends parallel to the local chordal plane and intersects the proximal end of the first section. The second section is oriented such that the upstream surfaces of the first and second sections together define a concave profile in cross section.

A gurney flap arrangement includes: an airfoil 2 with a trailing edge 6 and an opening 14 in a surface 8 of the airfoil 2; a gurney flap 1 having a first position in which at least a portion of the gurney flap 1 extends through the opening 14 and projects outwardly from the airfoil surface 8, and a second position in which the gurney flap 1 does not project from the airfoil surface 8 or projects outwardly from the airfoil surface 8 to a lesser extent; and a gurney flap actuator 3 for moving the gurney flap 1 between at least the first position and the second position.

A wind turbine blade includes a trailing edge flap having a flap part protruding from the trailing edge on the pressure side of the blade. The flap part has a first section and a second section each having an upstream surface arranged to face an oncoming airflow in use. The first section extends from the trailing edge and has a proximal end and a distal end in cross-section. The proximal end is located at or near the trailing edge and the distal end is spaced apart from the trailing edge. The first section is oriented such that an obtuse angle is defined between the upstream surface of the first section and a plane that extends parallel to the local chordal plane and intersects the proximal end of the first section. The second section is oriented such that the upstream surfaces of the first and second sections together define a concave profile in cross section.

An air flow channeling yaw control device includes a vane cover, a vane array, and an actuator. The vane array includes a plurality of vanes, each of the plurality of vanes comprising a first edge and a second edge, the first edge being hingedly coupled to the vane cover and the second edge being hingedly coupled to a wing of an aircraft. The wing includes a leading edge and a trailing edge. The actuator is configured to move the plurality of vanes from a retracted position into a deployed position. The plurality of vanes, when moved into the deployed position, are configured to direct a flow of air flowing over the leading edge of the wing through channels created by the plurality of vanes. The plurality of vanes, when moved into the retracted position, are configured to retract within the wing.

An air flow channeling yaw control device includes a vane cover, a vane array, and an actuator. The vane array includes a plurality of vanes, each of the plurality of vanes comprising a first edge and a second edge, the first edge being hingedly coupled to the vane cover and the second edge being hingedly coupled to a wing of an aircraft. The wing includes a leading edge and a trailing edge. The actuator is configured to move the plurality of vanes from a retracted position into a deployed position. The plurality of vanes, when moved into the deployed position, are configured to direct a flow of air flowing over the leading edge of the wing through channels created by the plurality of vanes. The plurality of vanes, when moved into the retracted position, are configured to retract within the wing.

Systems and methods for reducing or weakening the shocks acting on an airfoil, such as an airfoil of an airplane wing. In one embodiment, the length of an airfoil is increased by shifting the trailing edge aft by installing a trailing edge extender. In one embodiment, the length and shape of an airfoil is changed by shifting the trailing edge aft and downward by installing a trailing edge extender. In one embodiment, an airfoil is changed by removing a portion of the wing at the trailing edge and increasing the camber by installing a trailing edge modifier to adjust the circulation surrounding the wing and redistribute loading of the wing. Modifications of an airplane wing, including installing a trailing edge extender, are easy to implement, do not require span extensions or tip devices, and improve fuel efficiency.

An airfoil that comprises a chamber having a forward-facing chamber opening may result in increased lift and decreased drag relative to a standard airfoil having deployed flaps, for example on an airplane wing. In embodiments, the chamber opening is located on or near the pressure surface of the airfoil. The airfoil chamber may enhance the lift-generating ability of the airfoil due to increased pressure at the pressure surface.

An adaptive trailing edge system for an aircraft may include an adaptive trailing edge element mounted to a trailing edge. An electric motor actuator having an electric motor may be configured to actuate the adaptive trailing edge element. A linkage system may couple the electric motor actuator to the adaptive trailing edge element for actuation thereof.