Patent ID: 7275722

Claim:
An aircraft comprising a wing, the wing comprising a root, a tip, and a wingtip device mounted in the region of the tip, there being a first plane with which the wing is generally aligned, and a second plane which is vertical and includes the longitudinal axis of the aircraft, the wingtip device being rotatably moveable between a first position and a second position, and being so arranged that, during flight of the aircraft, the bending moment at the root changes in dependence on the position of the wingtip device so that the maximum bending moment at the root of the wing sustained during high-load flight conditions may be reduced, wherein the axis of rotation of the wingtip device is so positioned that: (a) the acute angle between the axis of rotation and the first plane is less than 45 degrees, and (b) the acute angle between the axis of rotation and the second plane is between 5 and 30 degrees, and wherein the axis of rotation of the wingtip device is so positioned and the wing and wingtip device are so arranged that: (c) the mean incidence of the wingtip device, when the wingtip device is in the second position, is less than the mean incidence of the wingtip device were the wingtip device in the first position.