 Experiments showed the need for only a small number of design changes , mainly involving the wing profile and positioning . To improve high @-@ alpha performance , the leading edge of the wing was drooped , especially on outer sections , a dog @-@ tooth was introduced to control spanwise flow , and the entire wing given a slight negative camber which helped control trim drag and pitch @-@ up . The area rule principle , made public in 1952 , was also applied to the design . This resulted in several changes including the addition of a tailcone , sharpening the radar nose profile , thinning the intake lips , and reducing the cross @-@ sectional area of the fuselage below the canopy . 
