 Typically one wing has a significantly shorter span, although some designs keep the upper and lower spans nearly equal while reducing the lower chord.Examples include the series of Nieuport military aircraft — from the Nieuport 10 through to the Nieuport 27 which formed the backbone of the Allied air forces from 1915 until 1917, and which were widely copied.The Albatros D.III and D.V, which copied the general layout from Nieuport similarly provided the backbone of the German forces.