Winglet

A winglet is a small, roughly vertical extension fitted to an aircraft wingtip that reduces the drag-inducing vortices that form there, improving fuel efficiency, range, and climb performance without significantly increasing the wing's overall span. Patents for wingtip end-plates go back to the English engineer Frederick W. Lanchester in 1897, and the American engineer William E. Somerville patented the first functional winglet in 1910, but the modern winglet stems from NASA engineer Richard T. Whitcomb's research in the 1970s, prompted by that decade's oil crisis; a joint NASA and US Air Force team flight-tested Whitcomb's designs in 1979 and 1980. The Learjet 28, shown publicly in 1977, was the first commercial aircraft to fly with winglets. Modern commercial jets typically gain four to six percent in fuel efficiency from winglets, and later variants such as blended winglets and raked wingtips appear on aircraft including the Boeing 787 and Airbus A350; the same wingtip-vortex principle has since been applied to helicopter rotors, propellers, and wind turbine blades.