History of Hoerner wing tip, Dr. Sighard Hoerner worked on the Fiesler Storch’s Stork, a short takeoff and landing as called STOL reconnaissance and liaison aircraft. During the Second World War. Hoerner worked as head of design aerodynamics for Junkers and later for Messerschmitt. After the war he was invited to come to the United States to work on aerodynamic research at Wright Field in Dayton Ohio. There while working on new concepts for high performance for Navy fighters and Hoerner designed the wing tip that bears his name. He was one of the first aerodynamicists to acknowledge the existence of the wingtip vortex and the corkscrew-shaped wake that forms on a wing's outboard edge and the Hoerner wing tip was specifically designed to minimize the effects of wingtip vortices on lift drag stability and control.[2]
The hoerner wingtip is named after the German aerodynamicist Sighard Hoerner who showed its effectiveness to be superior to that of the round wingtip. In fact, its primary advantage is that its impact on the effective AR is neutral, rather than negative like that of the round wingtip. Hoerner wingtip are used on a number of aircraft, most notably the Grumman American AA-5 series of aircraft, produced between 1971 and 2005. The wingtip increases dihedral effect. Theoretically, it is intended to shift the wingtip vortex farther outboard and this requires a sharp edge separating the upper and lower surfaces along the aft trailing edge. Normally, the first part of the leading edge features a round geometry to prevent the upper surface from stalling at low angle of attack. Gain in effectiveness or calculation in effective span: ΔAR = 0.00 [8 p.446]