Abstract: One or more aerodynamic bodies of preselected shape and placement are employed on the lower surface of an aircraft wing or other aerodynamic lifting surface for the purpose of reducing its drag. These anti-drag bodies singly or collectively provide a reduction in the lower speed profile drag of the associated lifting surface, an increase in its lift at a given angle of attack, and an increase in its critical Mach number.

Abstract: Vortex diffusion means for an aircraft having lift structure rooted therein that extends outboard to a structure tip from which a discrete tip vortex develops when said tip is propelled through the air. A sub-wing extends from the tip of the lift structure. Preferably, the sub-wing has its leading edge or upper lead surface tangent to the upper lead surface of the lift structure and a span axis parallel to the span axis of the lift structure. The sub-wing's chord is sized to equally divide the bound vorticity shed at the tip of the lift structure so that twin discrete vortices are generated. One discrete vortex forms along the streamwise edge of the lift structure's tip and the other forms along the streamwise edge of the sub-wing's tip. The distance between the two vortices is in the range of from 25 to 50% of the local chord of the lift structure.