The Engineering Compromise Behind Every Fuel-Saving Winglet

Winglets look like a simple add-on at the end of an aircraft’s wing, but they’re the product of a long engineering trade-off. The key benefit is reduced induced drag, which stems from wingtip vortices created as the aircraft generates lift—NASA research in the 1970s helped prove that extending the wingtip can weaken those vortices. A test program beginning in 1977 found 9-foot (2.7-meter) winglets improved the lift-to-drag ratio by 7% and cut induced drag by 20%, without harming handling. Commercial use followed from the late 1980s, though additional wetted area and structural loads complicate the economics.