The project aerodynamicist on the design of the Me 262 was Ludwig Bölkow. He initially designed the wing using NACA airfoils modified with an elliptical nose section. Later in the design process, these were changed to AVL derivatives of NACA airfoils, the NACA 00011-0.825-35 being used at the root and the NACA 00009-1.1-40 at the tip. The elliptical nose derivatives of the NACA airfoils were used on the horizontal and vertical tail surfaces. Wings were of single-spar cantilever construction, with stressed skins, varying from skin thickness at the root to at the tip. To expedite construction, save weight and use less strategic materials, late in the war, wing interiors were not painted. The wings were fastened to the fuselage at four points, using a pair of and forty-two bolts.