Tandem Wing

A tandem wing aircraft has two main wings, with one located forward and the other to the rear. Both wings contribute to lift. In the case where the rearmost tandem wing is smaller so that it looks like an oversize tailplane it is referred to as a "Delanne wing" - from Maurice Delanne, a French designer of tandem wing aircraft. In a tandem wing design the lift vectors on the two wings are spread far apart longitudinally, allowing them to act together to achieve stability and control.

This is different from a biplane, in which the wings are stacked more or less vertically, one above the other, such that their lift vectors are very close together and a separate horizontal stabiliser surface is required, placed well forward or aft of the main wings. It differs from the canard or "tail-first" configuration in that the forward wing contributes a major part of the lift, typically more than 50%.