Patent ID: 7971832

Claim:
A tip device to act as an outboard continuation of an aerodynamic lifting surface, said lifting surface being without anhedral, wherein said device has a downward cant angle and in planform has a leading edge swept back in relation to the leading edge of the lifting surface inboard thereof, a trailing edge swept back in relation to the trailing edge of the lifting surface inboard thereof and at a sweep angle which increases in the outboard direction of the device at least from a position substantially outboard of the root of the device, and a chord reducing substantially monotonically from the root to the tip of the device; wherein the aft extension of the device, from the position from which its trailing edge is swept back in relation to the trailing edge of the lifting surface inboard thereof, is greater than about two thirds of the lifting surface chord length at said position; wherein both the leading and trailing edges of the device have a downward cant angle which increases in the outboard direction of the device, and wherein the trailing edge at the tip of the device is located below the lower surface crest point of the lifting surface at the position from which the downward cant angle commences by at least twice the maximum lifting surface thickness at that position.