Initially, the structure of the Hurricane's cantilever wing consisted of two steel spars, which possessed considerable strength and stiffness. The wing was described by aviation publication Flight as being relatively straightforward to manufacture, employing simple vertical jigs to attach the two spars, after which the wing ribs would be installed using horizontal bolts, forming separate units between the front and rear spars. Hydraulically-actuated split trailing edge flaps were present on the inner end of the wings. The original wing was predominantly fabric-covered, like the fuselage, while some use of lightweight metal sheets was made upon the exterior surface of the inner wing and its leading edge. The majority of the Flight control surfaces, such as the Frise-type ailerons, also had fabric coverings.