winglets

Winglets are aerodynamic devices mounted at the tips of aircraft wings. They are designed to reduce induced drag caused by wingtip vortices, by limiting the spanwise flow of air around the wing tip. By reducing wingtip circulation, winglets can improve the lift-to-drag ratio, contributing to lower fuel consumption, increased range, and improved climb performance. They can also influence stall characteristics and structural loads, depending on the specific design.

The concept has roots in lift and vortex studies, but was popularized by NASA engineer Richard Whitcomb in the 1970s. After years of development, the first large-scale commercial use occurred in the late 1990s with blended winglets produced by Aviation Partners Boeing, notably on the Boeing 737 family. Since then, winglets and related tip devices have become common on many modern airliners and business jets, with various manufacturers offering different configurations.

Designs vary. Blended winglets are upward- or outward-curved surfaces integrated smoothly into the wingtip. Wingtip fences consist of small horizontal surfaces on the upper and lower wingtips. Split scimitar winglets add a second blade below the wingtip. Some designs also include extended or curved tips known as raked wingtips, which reduce drag in a related way.

Benefits and trade-offs are fleet- and mission-dependent. Typical fuel-burn reductions range from a few percent to around five percent under suitable conditions, offset by added weight, cost, and maintenance considerations. Winglets are now widely adopted on many modern airliners and business jets, reflecting their role in improving aerodynamic efficiency.