A winglet is a small vertical extension on the tip of a wing. It is an up-turned, aerodynamic device that diminishes wingtip vortices and reduces the induced drag created by every airplane. By curbing wake vortices, the winglet markedly improves performance and fuel efficiency, so this miniature vertical aerofoil has migrated from a novel experiment to a standard feature on modern commercial and business aircraft.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
What are winglets on an aircraft?
Winglets are vertical or angled extensions at the tips of an airplane's wings, and such devices reduce drag by increasing the height of the lifting system without greatly increasing the wingspan. Wingtip devices are intended to boost the efficiency of fixed-wing aircraft by reducing drag. A nearly vertical airfoil at an airplane's wingtip reduces drag by inhibiting turbulence.
A winglet is a small aerodynamic device attached to the tips of an aircraft's wings. Winglets are small upward-bending extensions that also face downward, in which case they are called drooped wingtips. They are vertical, angled, and come in various forms like blended winglets with smooth aerodynamic curves, split-scimitar winglets, single or double winglets, and raked wingtips. Because winglets reduce induced drag, they refine the two-dimensional flow across the wing, extend aircraft range, and drop fuel consumption by up to 4%, even though they add modest weight.
A winglet allows the aircraft to travel more efficiently by decreasing induced drag. I understand the importance of wingtips and their function in minimizing drag.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
What do winglets on an airplane do?
Winglets are vertical aerofoils located on the tips of an airplane wing, functioning as small wing extensions that produce a portion of lift, enhance effective wing spans, and serve as a barrier between two distinct air flows. They primarily reduce induced drag caused by wingtip vortices, decrease lift-induced drag, reduce overall drag of the aircraft, and oppose drag. Winglets reduce the strength of the tip vortex, diminish the intensity of wake vortices, and boost the directional stability of the aircraft, especially during turbulence.
By decreasing turbulence and increasing the lift-to-drag ratio, winglets enhance lift and enable better climb performance, allow slightly lower angles of attack for the same amount of lift, and permit higher cruising altitudes. These aerodynamic improvements lead to measurable operational benefits: winglets reduce fuel consumption by up to six percent, make turbulence more bearable, refine noise reduction during takeoff and landing, and extend range by about 6.5 percent through better payload-range capability. Winglets give performance improvement of between five and seven percent, yet they increase weight of an aircraft and require structural reinforcements that add weight and increase the overall surface area of the aircraft model.
Winglets’ main purpose is to decrease drag generated by wing tip vortices, and this refinement creates a considerable distinction over billions of miles flown. The devices decrease the fleet's oil expanse by burning less gas, which translates to better fuel economy. From an environmental viewpoint, I recognize a greater benefit because winglets decrease the fleet's carbon footprint.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
How do airplane winglets work?
Winglets are mini airfoils standing nearly vertical at the wingtip. They interfere with the high-pressure air under the wing that tries to curl upward into the low-pressure region above the wing. This flow forms energetic wingtip vortices. By blocking these vortices, the winglets act as aerodynamic barriers that inhibit formation of the swirling masses and weaken the backward part of lift known as induced drag. Induced drag is a byproduct of producing lift, and each kilogram of it both reduces performance and increases kerosene consumption.
Because the weakened vortices leave less energy in the wake, the aircraft needs less thrust for the same lift. NASA Dryden Flight Research Center measured a 6.5% drop in fuel use after adding winglets. Airlines therefore keep the same schedule while venting less carbon. Some modern winglets add downward-facing tips or smooth curved transitions that extend effective height without extra width, giving an even larger drag cut while meeting the reinforcement that winglets naturally require.
Which aircraft have winglets?
Commercial aviation incorporated winglets when the Boeing 747-400 was announced in 1985 as the first commercial airliner ever to feature them, using a combination of canted winglets and extended spans that Boeing stated contributed 3.5% more range. Virgin Atlantic introduced the devices to its fleet in November 1993 with the Airbus A340-300, and the A340 family together with the A330 quickly followed with standard canted winglets that are bolt-on additions to an existing wing. On newer Airbus narrow-bodies the same blended form is called a sharklet and is fitted to A320 Enhanced, A320neo, A330neo, A350 and A380 models, while older A320-family jets carry simpler wingtip fences.
Boeing 737s from the NG onward carry 8 ft 2 in (2.49 m) blended or split-scimitar winglets that are now flown by roughly 1,700 operators for fuel savings and extended range, and the 737 MAX AT winglet is billed as the most efficient ever designed for a production airplane. After launch-customer Bombardier put the CRJ-100/200 into service in 1992 as the first regional airliner with winglets, later 757 and 767 aircraft were frequently retrofitted with 11 ft (3.35 m) tall blended winglets, whereas the 777, 787 and 747-8 dispense with classical winglets in favour of raked wingtips whose curving surfaces provide the same aerodynamic benefit.
Modern military and business aircraft adopt the idea: the Tupolev Tu-204 was the first narrow-body to feature winglets in 1994, the Lockheed Martin C-130J Super Hercules uses them to boost lift and fuel efficiency, and the A-10 carries simple downturned or dropped wingtips. In the executive market the Learjet 28 pioneered winglets in 1977, Gulfstream and Cessna Citation families incorporate several winglet designs, and the distinctive spiroid type was originally tested on a Gulfstream II in 1993 before being refined on a Falcon 50 in 2010. Thus, from regional jets to long-haul wide-bodies, virtually all major new-generation passenger and freight aircraft now sport some form of wing-tip device, making winglets a familiar sight on modern commercial aircraft.
The Boeing 737 Next Generation program is possibly the most identifiable instance of winglets in service today. I am particularly taken by the sophisticated configurations like the raked wing tips on the Boeing 777X and the characteristic upward-swept wing tips on the Airbus A350. These versions imply that applied scientists are ceaselessly modifying the idea, because there is an optimal design for each particular aircraft's wing construction and functional cross-sectional.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
Who invented airplane winglets?
William E. Somerville patented the first functional winglets in 1910 and installed the devices on his early biplane and monoplane designs. In 1897 Frederick W. Lanchester had already patented wing end-plates, and he later related wing-tip devices to soaring eagles while designing and testing winglets on gliders.
The modern era began when Richard T. Whitcomb, working at Langley Research Center, refined Lanchester's design in the 1970s, conducted computer and wind-tunnel tests, and conceived vertical winglets, earning credit for the world's first true winglet. NASA validated the concept in 1976 with further wind-tunnel tests, and the first actual winglet appeared in 1975 on the Rutan VariEze, a canard aircraft designed by Burt Rutan.
