Wing tip device

A method of operating a wing having a wing tip device fixed to the outboard end of the wing, the wing defining a wing plane, and the wing tip device comprising:

• an upper wing-like element projecting upwardly with respect to the wing plane and having a trailing edge;
• and
• a lower wing-like element fixed with respect to the upper wing-like element and having a root chord and a trailing edge, the lower wing-like element root chord intersecting with the upper wing-like element, and the lower wing-like element projecting downwardly from the intersection,
• wherein the upper wing-like element is larger than the lower wing-like element and the trailing edge of the lower wing-like element is adjacent the trailing edge of the upper wing-like element at the intersection, and
• wherein an included angle between the upper and lower wing-like elements at the intersection is less than, or equal to, 160 degrees, and
• the method comprising subjecting the wing to aerodynamic loads such that the wing shape undergoes aeroelastic deformation to a state in which wing bending causes rotation of the wing tip device about the wing root such that the tip of the lower wing-like element extends further outboard in the spanwise direction than the tip of the upper wing-like element.