Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position of one or more propeller blade treatments of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more propeller blade treatments that may be adjusted between two or more positions. Based on the position of the propeller blade treatments, the airflow over the propeller is altered, thereby altering the sound generated by the propeller when rotating. By altering the propeller blade treatments on multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel, reduce, and/or otherwise alter the total sound generated by the aerial vehicle.

A flap of an aircraft includes a flap body that is provided deployably with respect to a main wing, an inclined portion that protrudes from an upper surface of a tip part on at least an outboard side in a span direction of the flap body and is inclined with respect to an aircraft axis direction, and a protruding portion that smoothly protrudes from a lower surface of the tip part on at least the outboard side. A rear end of the inclined portion is located closer to a side end edge of the tip part in the span direction of the flap body than a virtual line that passes through a front end of the inclined portion and is parallel to the aircraft axis direction.

A control surface component for reducing a noise level generated by the flow around the control surface component, in particular flap component, for a high-lift device of a wing of an aircraft, having a lift body, which is designed or configured to generate lift and which comprises a lift body end region, a lift body suction side and a lift body pressure side, wherein a foam body, which can be mounted adjoining the lift body end region, is formed separately from the lift body as an integral element and is exposed, is designed or configured to provide, in the mounted state, a plurality of flow paths which fluidically connect the lift body suction side and the lift body pressure side to compensate for a pressure difference prevailing between the lift body suction side and the lift body pressure side.

A pylon for attaching a turbine engine, the pylon configured to connect the engine to a structural element of an aircraft. The pylon includes a streamlined profile defined by two opposite lateral faces and defined longitudinally between a leading edge and a trailing edge. On each of its lateral faces the pylon includes a series of deflectors that are transversely spaced apart from one another and that define between them convergent and curved channels configured to accelerate air streams flowing within the channels on aircraft takeoff or in flight to deflect the air streams towards a jet of the engine.

An airfoil is provided having reduced noise generation for use with an aircraft. The airfoil includes a body and a cover. The body has a leading edge spaced from a trailing edge and a side surface disposed between the leading edge and the trailing edge. The body defines an inlet proximate the leading edge and configured to receive air. The side surface defines an outlet in fluid communication with the inlet. The outlet is configured to exhaust air away from the side surface. The cover overlies the inlet and is movable between a first and a second cover position. The cover is configured to prevent movement of air through the inlet when the cover is in the first cover position and configured to permit movement of air through the inlet when the cover is in the second cover position.

A propulsion assembly for aircraft, the assembly including a turbojet having at least one unducted propulsion propeller; and an attachment pylon for attaching the turbojet to a structural element of the aircraft, the pylon being positioned on the turbojet upstream from the propeller and having an airfoil extending transversely between a leading edge and a trailing edge, the trailing edge of the airfoil of the pylon includes a cutout extending longitudinally over a fraction of the trailing edge facing at least a portion of the propeller, the cutout being configured to increase locally the distance between the trailing edge and the propeller, the cutout presenting an outline having a curved shape presenting at least two points of inflection.

Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

A movable aerodynamic surface for an aircraft is disclosed including a skin having a first skin portion and a second skin portion both extending from the leading edge to the trailing edge and together surrounding an interior from opposite sides, and a stiffener arrangement arranged in the interior and including at least an inboard stiffener in the area of the inboard end and/or an outboard stiffener in the area of the outboard end. At the inboard end between the first skin portion, the second skin portion and the inboard stiffener an inboard cavity is formed, and/or at the outboard end between the first skin portion, the second skin portion and the outboard stiffener an outboard cavity is formed. An acoustic filler arrangement including multiple filler elements is arranged within the inboard cavity and/or the outboard cavity for reducing noise.

Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

A high-lift device includes a flap body which is provided at a rear portion of a main wing which generates a lift for the air vehicle such that the flap body is deployed with respect to the main wing and stowed in the main wing and extends along a wingspan direction of the main wing; and a gap increasing section provided at an end portion of the flap body in an extending direction of the flap body, to increase a gap between the rear portion of the main wing and a front portion of the flap body in a state in which the flap body is deployed.