The XB-70 used compression lift, which arose from a shock wave generated by the sharp leading edge of the central engine intake splitter plate below the wing. At Mach 3 cruising speed, the shock wave attached along the wing leading edge, preventing the high pressure behind the shock front from leaking up over the wing. The compression lift provided five percent of the total lift. The wing included inboard camber to more effectively use the higher pressure field behind the strong shock wave. Unique among aircraft of its size, the outer portions of the wings were hinged, and could be pivoted downward by up to 65 degrees, acting almost as a type of variable-geometry wingtip device. This increased the aircraft's directional stability at supersonic speeds, shifted the center of pressure to a more favorable position at high speeds, and strengthened the compression lift effect. With the wingtips drooped downwards, the compression lift shock wave would be further trapped under the wings.