The Whitley featured a large rectangular-shaped wing; its appearance led to the aircraft receiving the nickname ""the flying barn door"". Like the fuselage, the wings were formed from three sections, being built up around a large box spar with the leading and trailing edges being fixed onto the spar at each rib point. The forward surfaces of the wings were composed of flush-riveted, smooth and unstressed metal sheeting; the rear 2/3rds aft of the box spar to the trailing edge, as well as the ailerons and split flaps was fabric covered. The inner structure of the split flaps was composed of duralumin and ran between the ailerons and the fuselage, being set at a 15–20 degree position for taking off and at a 60 degree position during landing. The tailplanes employed a similar construction to that of the wings, the fins being braced to the fuselage using metal struts the elevators and rudders incorporated servo-balancing trim tabs.