Book excerpt: A limited investigation was made at high subsonic speeds to determine the effects of a wing leading-edge radius on the aerodynamic characteristics of a sweptback-wing-fuselage combination with leading-edge flaps and chord-extensions. The basic wing had 45 degree sweepback, aspect ratio 4, taper ratio 0.3, and NACA 65A006 airfoil section. The leading-edge shapes considered consisted of a sharp leading edge, a normal airfoil leading edge, and a leading edge formed by using three times the normal radius and fairing the new nose contour smoothly into the normal airfoil. The investigation was made in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.80 to 0.92 and an angle-of-attack range of -2 to 24 degrees. Lift, drag, and pitching-moment data were obtained for all configurations with leading-edge flap deflections of 0 to 6 degrees.