Abstract: An aircraft wing is disclosed having a root end, a tip end, a span extending between the root end and the tip end, a leading edge, a trailing edge and a chord extending between the leading edge and the trailing edge, and including a main fixed wing portion having an inboard portion adjacent the root end, and an outboard portion adjacent the tip end. A wing tip device attached to the tip end of the wing; and a movable flight control surface connected at the outboard portion of the main fixed wing portion and having a leading edge, a trailing edge and a chord extending between the leading edge and the trailing edge. A ratio of the local chord length of the movable flight control surface to the local chord length of the wing varies in the spanwise direction.

Abstract: A stall trigger system is disclosed having an aircraft wing tip or aircraft wing tip device, a plurality of sets of stall triggers distributed along a span of the aircraft wing tip or aircraft wing tip device. Each set of stall triggers comprises one or more stall triggers which can be activated to trigger local separation of air flow over the aircraft wing tip or aircraft wing tip device, and each set of stall triggers has a different activation threshold. A control system configured to monitor a parameter, and activate each set of stall triggers in response to the parameter reaching its respective activation threshold.

Abstract: An aircraft wing including a leading edge slat and a fixed aerofoil portion. The leading edge slat is moveable between a stowed position and deployed position. In the deployed position a trailing edge of the leading edge slat includes a sealed portion and an unsealed portion. The sealed portion forms a seal with the fixed aerofoil portion and the unsealed portion provides an airflow gap between the leading edge flap and the fixed aerofoil portion. The invention provides substantially the same benefits as a sealed leading edge slat whilst improving stall control behavior in local zones around the unsealed portion.

Abstract: A wing tip device having a first wing tip device element for attaching at a first wing tip device element root to a tip of an aircraft wing, and a second wing tip device element extending from a second wing tip device element root to a second wing tip device element tip, the second wing tip device element root outboard, when viewed in the wing planform direction, of the first wing tip device element root; the first wing tip device element having a first wing tip device element leading edge and a first wing tip device element trailing edge, and the second wing tip device element having a second wing tip device element leading edge and a second wing tip device element trailing edge; and a fairing between the first and second wing tip device element which extends aft from the second wing tip device element trailing edge.

Abstract: A linear step discontinuity on the lower surface of the lifting surface is disclosed extending from the front of the lifting surface, possibly the leading edge, and may extend in the direction of the line of flight towards the trailing edge. The linear step discontinuity represents a step up if moving from the outboard end to the inboard end, such that in use fluid moving over the lifting surface tumbles over the linear step discontinuity to create a vortex in the fluid passing over the upper surface. The lifting surface may be an aircraft wing or in particular a winglet on an aircraft wing. The linear step discontinuity may be provided by the straight edge of a semi-circular object integrated into or adhered to the surface of the lifting surface.

Abstract: A wing tip device having a first wing tip device element for attaching at a first wing tip device element root to a tip of an aircraft wing, and a second wing tip device element extending from a second wing tip device element root to a second wing tip device element tip, the second wing tip device element root outboard, when viewed in the wing planform direction, of the first wing tip device element root; the first wing tip device element having a first wing tip device element leading edge and a first wing tip device element trailing edge, and the second wing tip device element having a second wing tip device element leading edge and a second wing tip device element trailing edge; and a fairing between the first and second wing tip device element which extends aft from the second wing tip device element trailing edge.

Abstract: An aircraft wing (2) including a main wing (3) and a wing tip device (4) at the tip of the main wing (3), wherein the wing tip device (4) has a variation of leading edge droop with respect to unrolled span-wise position such that flow separation on the wing tip device (4) first occurs in an outboard region (O) of the wing tip device (4). The leading edge droop of the wing tip device (4) may be a maximum in an outboard region (O) of the wing tip device.

Abstract: A stall trigger system is disclosed having an aircraft wing tip or aircraft wing tip device, a plurality of sets of stall triggers distributed along a span of the aircraft wing tip or aircraft wing tip device. Each set of stall triggers comprises one or more stall triggers which can be activated to trigger local separation of air flow over the aircraft wing tip or aircraft wing tip device, and each set of stall triggers has a different activation threshold. A control system configured to monitor a parameter, and activate each set of stall triggers in response to the parameter reaching its respective activation threshold.

Abstract: A wing tip device for attaching to an aircraft wing comprising a first wing tip device element having a root end and a tip end; a second wing tip device element coupled to the tip end of the first wing tip device element; wherein the second wing tip device element has an inboard portion extending inboard from the tip end of the first wing tip device element and/or an outboard portion extending outboard from the tip end of the first wing tip device element, when viewed in the wing planform direction.

Abstract: A method of retrofitting a wing of a fixed wing aircraft is disclosed including the steps of providing an existing aircraft wing with a main fixed wing portion, and the main fixed wing portion having a tip end and an existing movable flight control surface connected adjacent the tip end. The existing movable flight control surface is then removed from the main fixed wing portion, and a wing tip device and movable flight control surface are selected as a pair to replace the existing movable flight control surface, with the selected movable flight control surface having an aerodynamic surface of different shape to the shape of the flight control surface removed from the wing. The selected wing tip device and movable flight control surface are then fitted to the main fixed wing portion.

Abstract: A method of retrofitting a wing of a fixed wing aircraft is disclosed including the steps of providing an existing aircraft wing with a main fixed wing portion, and the main fixed wing portion having a tip end and an existing movable flight control surface connected adjacent the tip end. The existing movable flight control surface is then removed from the main fixed wing portion, and a wing tip device and movable flight control surface are selected as a pair to replace the existing movable flight control surface, with the selected movable flight control surface having an aerodynamic surface of different shape to the shape of the flight control surface removed from the wing. The selected wing tip device and movable flight control surface are then fitted to the main fixed wing portion.

Abstract: An aircraft (5) including a wing (3) and a winglet (1) at the end of the wing, the winglet including: a root (7); a tip (9); a transition region (11) extending away from the root; and a wing-like region (13) extending from the distal end of the transition region to the tip. When the aircraft wing (3) is under the worst-case static loading, the tip of the winglet is located at the maximum spanwise extent of the winglet (1), but when the aircraft wing (3) is under the no-load condition, the wing-like region (13) is canted inboard such that the tip (9) of the winglet (1) is located inboard of the maximum spanwise extent of the winglet.

Abstract: A wing tip device having a first wing tip device element for attaching at a first wing tip device element root to a tip of an aircraft wing, and a second wing tip device element extending from a second wing tip device element root to a second wing tip device element tip, the second wing tip device element root outboard, when viewed in the wing planform direction, of the first wing tip device element root; the first wing tip device element having a first wing tip device element leading edge and a first wing tip device element trailing edge, and the second wing tip device element having a second wing tip device element leading edge and a second wing tip device element trailing edge; and a fairing between the first and second wing tip device element which extends aft from the second wing tip device element trailing edge.

Abstract: A wing tip device for attaching to an aircraft wing comprising a first wing tip device element having a root end and a tip end; a second wing tip device element coupled to the tip end of the first wing tip device element; wherein the second wing tip device element has an inboard portion extending inboard from the tip end of the first wing tip device element and/or an outboard portion extending outboard from the tip end of the first wing tip device element, when viewed in the wing planform direction.

Abstract: An aircraft wing (2) including a main wing (3) and a wing tip device (4) at the tip of the main wing (3), wherein the wing tip device (4) has a variation of leading edge droop with respect to unrolled span-wise position such that flow separation on the wing tip device (4) first occurs in an outboard region (O) of the wing tip device (4). The leading edge droop of the wing tip device (4) may be a maximum in an outboard region (O) of the wing tip device.

Abstract: A method of retrofitting a wing of a fixed wing aircraft is disclosed including the steps of providing an existing aircraft wing with a main fixed wing portion, and the main fixed wing portion having a tip end and an existing movable flight control surface connected adjacent the tip end. The existing movable flight control surface is then removed from the main fixed wing portion, and a wing tip device and movable flight control surface are selected as a pair to replace the existing movable flight control surface, with the selected movable flight control surface having an aerodynamic surface of different shape to the shape of the flight control surface removed from the wing. The selected wing tip device and movable flight control surface are then fitted to the main fixed wing portion.

Abstract: An aircraft (5) including a wing (3) and a winglet (1) at the end of the wing, the winglet including: a root (7); a tip (9); a transition region (11) extending away from the root; and a wing-like region (13) extending from the distal end of the transition region to the tip. When the aircraft wing (3) is under the worst-case static loading, the tip of the winglet is located at the maximum spanwise extent of the winglet (1), but when the aircraft wing (3) is under the no-load condition, the wing-like region (13) is canted inboard such that the tip (9) of the winglet (1) is located inboard of the maximum spanwise extent of the winglet.

Abstract: A method of designing a winglet (3) for an aircraft (7) including: defining the location of the winglet root; defining a maximum height for the winglet tip; defining a maximum span for the winglet; creating the winglet shape by locating the winglet root (13?), locating the winglet tip (15?) at the location of maximum height and maximum span, and connecting the winglet root (13?) to the winglet tip (15?) using a winglet shape. The winglet shape includes a curved transition region (17?) extending away from the root, and a wing-like region extending from the distal end of the transition region (17?) to the winglet tip (15?). The step of creating the winglet shape includes iteratively changing the curvature and/or the location of the center of the curvature of the transition region, whilst maintaining the locations of the winglet root and winglet tip.