A fluid foil has a main fixed portion and a tip portion movably mounted at a tip end of the main fixed portion. The main fixed portion has an upper surface and a lower surface, and the tip portion has an upper surface and a lower surface. The fluid foil is operable in: a) a first configuration in which the upper surface of the tip portion is angled downwardly with respect to the upper surface of the main fixed portion; and b) a second configuration in which the tip portion is rotated upwardly with respect to the first configuration such that the upper surface of the tip portion and the upper surface of the main fixed portion are substantially continuous surfaces. The movement of the tip portion with respect to the main fixed portion is exclusively passively actuated by movement of the foil with respect to a surrounding fluid.

A manual brake override system includes a gear system, an electric motor in operative communication with the input of the gear system, a holding brake in operative communication with the input of the gear system. The holding brake is configured to prevent movement within the gear system when engaged. A manual handwind is provided in operative communication with the input of the gear system and the manual handwind and holding brake are configured such that the input of the gear system can be driven, with the manual handwind, whilst the holding brake is engaged.

A clutch for use in actuating an aircraft wing tip device is disclosed. The clutch includes first and second friction members each having a frusto-conical friction surface, and a third friction member arranged coaxially with, and between, the first and second friction members. The third friction member has first and second frusto-conical friction surfaces. When the clutch is engaged, the first and second friction surfaces of the third friction member are brought into contact with the friction surfaces of the first and second friction members, respectively. The clutch also includes spacer means operable to separate the friction surfaces from one another when the clutch is in a disengaged state.

An aircraft with wing tip devices, for example, folding wing tips, is disclosed. The folding wing tip may have a flight configuration for use during flight, and a ground configuration for use in ground-based operations. The ground configuration creates a shorter wing span than when the aircraft is in the flight configuration. A hinge arrangement protrudes beyond an outer surface of the fixed wing and wing tip device. In order to reduce the aerodynamic effect of the protruding hinge a fairing may be provided. In the flight configuration the fairing comprises a front portion blended into and extending rearwardly from the leading edge of the fixed wing and the wing tip device.

An air-redirection formation for a tip portion of an aerofoil such as an aircraft wing includes: a first portion, which includes a first surface which forms a continuation of the aerodynamic lifting surface of the wing, and which is for directing vortices away from the aerofoil; and a second portion, which is spaced from the first portion and which is positioned to generate uplift due to the directed vortices.

An aerodynamic structure is disclosed having a lifting surface, a control device and an actuation mechanism. The lifting surface has a root and a tip, and is deformable during operation of the aerodynamic structure. The control device is movably attached to the lifting surface, at or near the tip. The actuation mechanism is for controlling movement of the control device, and is configured to transmit deformation movement of the lifting surface to the control device.

A folding wing having a wing tip device (3) rotatable between flight and ground configurations, about an Euler axis of rotation (11). The wing tip device (3) and a fixed wing (1) are separated along an oblique cut plane (13) passing through the upper and lower surfaces of the folding wing. A rotational joint (15) for coupling the wing tip device (3) to the fixed wing (1) during rotation between the ground and flight configurations. The rotational joint includes a follower (17a) and a guide (17b), one which being fixed relative to the wing tip device and the other being fixed relative to the fixed wing. The follower and guide interlock such as by interlocking rings. The follower is received in the guide such that during rotation between the ground and flight configurations the follower moves along the arcuate path defined by the guide.

A winglet linked to a wing of an aircraft and equipped with a configuration changing device, the winglet being configured to be deformed elastically between a first configuration in the absence of an activation loading and a second configuration in the presence of an activation loading. The configuration changing device comprises at least one blocking cable configured to hold the winglet in the second configuration and at least one blocking system which comprises a tank containing a material configured to occupy a solid state in which the material immobilizes the blocking cable and a liquid state in which the material does not immobilize the blocking cable and allows the displacement thereof. An aircraft comprises wings provided with the winglets.

The invention relates to a wing with two winglets and a respective airplane. An upstream winglet broadens a region of inclined airflow and a downstream winglet produces a thrust contribution therein.

A retractable vortex generator system for an aircraft. The system comprises a skin, a slot arranged on the skin, a plate comprising a contour configured for energizing the boundary layer of an air current, and driving means configured for rotating the plate between a first and a second position. In the first position at least part of the contour of the plate protrudes through the slot, and in the second position the plate is retracted within the slot.