Armstrong Whitworth Ape

The Armstrong Whitworth Ape was a British experimental biplane built by Armstrong Whitworth Aircraft in the early 1920s to answer all the questions of aerodynamics, and it first flew on 5 January 1926. It was designed to be infinitely adjustable: the fuselage could be lengthened or shortened, different fins and tailplanes could be fitted, and the incidence of the tailplane and wings, and the stagger, rake and dihedral of the wings, could all be altered. It could not be converted to a monoplane or fitted with a more powerful engine, and its whole tail was a single unit, so the tailplane incidence could not change without the fin. The first aircraft carried a comparatively small 180 hp Armstrong Siddeley Lynx engine that gave far less power than its heavy airframe needed, and the second Ape was given a bigger Bristol Jupiter, though the extra equipment mostly cancelled the added power. The Royal Aircraft Establishment operated it, and it saw occasional use throughout the 1920s.