Soon the design became too different from the Skyray to be considered just a variation of it, and the aircraft was assigned a new designation as the F5D Skylancer. Almost every part of the airframe was modified, though the basic form remained the same as did the wing shape, though it became much thinner. The wing skinning was reinforced, correcting a problem found in the F4D. The fuselage was 8 ft (2.4 m) longer and area ruled to reduce transonic drag, being thinner in the region of the wing roots. Everything was shaped to reduce drag and increase stability at high speed.
