History
During World War II, Hoerner developed flight technologies used on the German Fieseler 256 and various versions of the Junkers. After the war, Hoerner came to the United States to work at Wright Field in Ohio where he developed the wing tip named after him. The Hoerner wing tip was originally metal, designed to maximize lift, stability, control and drag. It is a predecessor to the modern resin-based fiberglass and plastic wing tips as well as the raked wing tip, another type of wing tip design, which is commonly used on short take-off and landing (STOL) designs.
Uses
Hoerner wing tips are used for lightweight planes since they lengthen the effective wingspan without the burden of additional weight. They are commonly used on lightweight planes such as Cessnas, Piper Cherokees, Comanches, Beech Bonanzas, Apaches and Aztecs. Some companies also offer a built-in tip tank for the Hoerner wingtip design.
Design
The Hoerner wing tip is thin with a rounded leading edge to encourage optimal air flow over the tip. The surfaces of the top and bottom of the wing are blended along a straight line, this line being as thin as possible to facilitate air flow. The trailing edge is sharp and deep to move the point where the vortices begin as far away from the main surface of the wing as possible in order to promote control and less drag. The convex underside of the tip serves to speed up the air passing under the tip to a speed more similar to the air passing over top of the tip, thus reducing turbulence.