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Wingtip devices are intended to improve the efficiency of
fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinc ...
by reducing drag. Although there are several types of
wing tip A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of sha ...
devices which function in different manners, their intended effect is always to reduce an aircraft's drag by partial recovery of the tip vortex energy. Wingtip devices can also improve aircraft handling characteristics and enhance safety for following aircraft. Such devices increase the effective aspect ratio of a wing without greatly increasing the
wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of ...
. Extending the span would lower
lift-induced drag In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or ...
, but would increase
parasitic drag Parasitic drag, also known as profile drag, is a type of aerodynamic drag that acts on any object when the object is moving through a fluid. Parasitic drag is a combination of form drag and skin friction drag. It affects all objects regardless of ...
and would require boosting the strength and weight of the wing. At some point, there is no net benefit from further increased span. There may also be operational considerations that limit the allowable wingspan (e.g., available width at airport gates). Wingtip devices help prevent the flow around the wingtip of higher pressure air under the wing flowing to the lower pressure surface on top at the wingtip, which results in a vortex caused by the forward motion of the aircraft, the winglet also reduces the lift-induced drag caused by
wingtip vortices Wingtip vortices are circular patterns of rotating air left behind a wing as it generates lift.Clancy, L.J., ''Aerodynamics'', section 5.14 One wingtip vortex trails from the tip of each wing. Wingtip vortices are sometimes named ''trailing'' ...
, and improves
lift-to-drag ratio In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under give ...
. This increases
fuel efficiency Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, wh ...
in powered aircraft and increases cross-country speed in
glider Glider may refer to: Aircraft and transport Aircraft * Glider (aircraft), heavier-than-air aircraft primarily intended for unpowered flight ** Glider (sailplane), a rigid-winged glider aircraft with an undercarriage, used in the sport of glidin ...
s, in both cases increasing
range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...
.
U.S. Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
studies indicate that a given improvement in fuel efficiency correlates directly with the causal increase in the aircraft's lift-to-drag ratio.


Early history


Wing end-plates

The initial concept dates back to 1897, when English engineer Frederick W. Lanchester patented wing end-plates as a method for controlling wingtip vortices. In the United States, Scottish-born engineer
William E. Somerville William E. Somerville (12 April 1869 – 25 September 1950) was a Scottish-American aircraft engineer. Early life William E. Sommervile's father was a mechanical engineer in Scotland. Sommerville studied as a marine engineer in Scotland. Somer ...
patented the first functional winglets in 1910. Somerville installed the devices on his early biplane and monoplane designs.
Vincent Burnelli Vincent Justus Burnelli (November 22, 1895 – June 22, 1964) was an American aeronautics engineer, instrumental in furthering the lifting body and flying wing concept. Biography Burnelli was born on November 22, 1895, in Temple, Texas. ...
received US Patent no: 1,774,474 for his "Airfoil Control Means" on August 26, 1930. Simple flat end-plates did not cause a reduction in drag, because the increase in profile drag was greater than the decrease in induced drag.


Hoerner wing tips

Following the end of World War II, Dr.
Sighard F. Hoerner Dr. Sighard F. Hoerner (born 18 April 1906, Münster, Germany — d. 22 June 1971, Brick Town, USA) was an important figure in the aerodynamics field and is known worldwide for his two compendiums of aerodynamic knowledge, ''Fluid-Dynamic Drag'' a ...
was a pioneer researcher in the field, having written a technical paper published in 1952 that called for drooped wingtips whose pointed rear tips focused the resulting wingtip vortex away from the upper wing surface. Drooped wingtips are often called "Hoerner tips" in his honor. Gliders and light aircraft have made use of Hoerner tips for many years. The earliest-known implementation of a Hoerner-style downward-angled "wingtip device" on a jet aircraft was during World War II. This was the so-called "Lippisch-Ohren" (Lippisch-ears), allegedly attributed to the
Messerschmitt Me 163 The Messerschmitt Me 163 Komet is a rocket-powered interceptor aircraft primarily designed and produced by the German aircraft manufacturer Messerschmitt. It is the only operational rocket-powered fighter aircraft in history as well as th ...
's designer
Alexander Lippisch Alexander Martin Lippisch (November 2, 1894 – February 11, 1976) was a German aeronautical engineer, a pioneer of aerodynamics who made important contributions to the understanding of tailless aircraft, delta wings and the ground effect, and a ...
, and first added to the M3 and M4 third and fourth prototypes of the
Heinkel He 162 The Heinkel He 162 ''Volksjäger'' (German, "People's Fighter") was a German single-engine, jet-powered fighter aircraft fielded by the Luftwaffe in World War II. Developed under the Emergency Fighter Program, it was designed and built quickly ...
A ''Spatz'' jet
light fighter A light fighter or lightweight fighter is a fighter aircraft towards the low end of the practical range of weight, cost, and complexity over which fighters are fielded. The light or lightweight fighter retains carefully selected competitive feat ...
for evaluation. This addition was done in order to counteract the dutch roll characteristic present in the original He 162 design, related to its wings having a marked
dihedral angle A dihedral angle is the angle between two intersecting planes or half-planes. In chemistry, it is the clockwise angle between half-planes through two sets of three atoms, having two atoms in common. In solid geometry, it is defined as the uni ...
. This became a standard feature of the approximately 320 completed He 162A jet fighters built, with hundreds more He 162A airframes going unfinished by
V-E Day Victory in Europe Day is the day celebrating the formal acceptance by the Allies of World War II of Germany's unconditional surrender of its armed forces on Tuesday, 8 May 1945, marking the official end of World War II in Europe in the Easter ...
.


Winglet

The term "winglet" was previously used to describe an additional lifting surface on an aircraft, like a short section between wheels on fixed undercarriage. Richard Whitcomb's research in the 1970s at
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
first used winglet with its modern meaning referring to near-vertical extension of the
wing tip A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of sha ...
s. The upward angle (or ''cant'') of the winglet, its inward or outward angle (or ''toe''), as well as its size and shape are critical for correct performance and are unique in each application. The wingtip vortex, which rotates around from below the wing, strikes the cambered surface of the winglet, generating a force that angles inward and slightly forward, analogous to a
sailboat A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminology ...
sailing
close hauled A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind. ...
. The winglet converts some of the otherwise-wasted energy in the wingtip vortex to an apparent
thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that syst ...
. This small contribution can be worthwhile over the aircraft's lifetime, provided the benefit offsets the cost of installing and maintaining the winglets. Another potential benefit of winglets is that they reduce the intensity of
wake vortices Wake turbulence is a disturbance in the atmosphere that forms behind an aircraft as it passes through the air. It includes variety of elements, the most significant of which are wingtip vortices and jetwash. Jetwash refers to the rapidly moving g ...
. Those trail behind the plane and pose a hazard to other aircraft. Minimum spacing requirements between aircraft operations at airports are largely dictated by these factors. Aircraft are classified by weight (e.g. "Light", "Heavy", etc.) because the vortex strength grows with the aircraft
lift coefficient In fluid dynamics, the lift coefficient () is a dimensionless quantity that relates the lift generated by a lifting body to the fluid density around the body, the fluid velocity and an associated reference area. A lifting body is a foil or a com ...
, and thus, the associated turbulence is greatest at low speed and high weight, which produced a high
angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...
. Winglets and wingtip fences also increase efficiency by reducing vortex interference with laminar airflow near the tips of the wing, by 'moving' the confluence of low-pressure (over wing) and high-pressure (under wing) air away from the surface of the wing. Wingtip vortices create turbulence, originating at the leading edge of the wingtip and propagating backwards and inboard. This turbulence 'delaminates' the airflow over a small triangular section of the outboard wing, which destroys lift in that area. The fence/winglet drives the area where the vortex forms upward away from the wing surface, since the center of the resulting vortex is now at the tip of the winglet. Aircraft such as the
Airbus A340 The Airbus A340 is a long-range, wide-body passenger airliner that was developed and produced by Airbus. In the mid-1970s, Airbus conceived several derivatives of the A300, its first airliner, and developed the A340 quadjet in parallel with ...
and the
Boeing 747-400 The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting ...
use winglets while other designs such as later versions of the
Boeing 777 The Boeing 777, commonly referred to as the Triple Seven, is an American long-range wide-body airliner developed and manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet. The 777 was designed to bridge the gap bet ...
and the
Boeing 747-8 The Boeing 747-8 is a wide-body airliner formerly developed by Boeing Commercial Airplanes, and the largest variant of the 747. After introducing the 747-400, Boeing considered larger 747 versions as alternatives to the proposed double-deck ...
have
raked wingtips Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag (physics), drag. Although there are several types of wing tip devices which function in different manners, their intended effect is always to redu ...
. The fuel economy improvement from winglets increases with the mission length. Blended winglets allow a steeper angle of attack reducing
takeoff Takeoff is the phase of flight in which an aerospace vehicle leaves the ground and becomes airborne. For aircraft traveling vertically, this is known as liftoff. For aircraft that take off horizontally, this usually involves starting with a t ...
distance.


Early development

Richard T. Whitcomb Richard Travis Whitcomb (February 21, 1921 – October 13, 2009) was an American aeronautical engineer who was noted for his contributions to the science of aerodynamics. Biography Whitcomb was born in Evanston, Illinois. His father, who had ...
, an engineer at
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
's
Langley Research Center The Langley Research Center (LaRC or NASA Langley), located in Hampton, Virginia, United States of America, is the oldest of NASA's field centers. It directly borders Langley Air Force Base and the Back River on the Chesapeake Bay. LaRC has fo ...
, further developed Hoerner's concept in response to the sharp increase in the cost of fuel after the
1973 oil crisis The 1973 oil crisis or first oil crisis began in October 1973 when the members of the Organization of Arab Petroleum Exporting Countries (OAPEC), led by Saudi Arabia, proclaimed an oil embargo. The embargo was targeted at nations that had supp ...
. With careful aeronautical design he showed that, for a given bending moment, a near-vertical winglet offers a greater drag reduction compared to a horizontal span extension. Whitcomb's designs were flight-tested in 1979–80 by a joint NASA/Air Force team, using a
KC-135 Stratotanker The Boeing KC-135 Stratotanker is an American military aerial refueling aircraft that was developed from the Boeing 367-80 prototype, alongside the Boeing 707 airliner. It is the predominant variant of the C-135 Stratolifter family of transpo ...
based at the
Dryden Flight Research Center The NASA Neil A. Armstrong Flight Research Center (AFRC) is an aeronautical research center operated by NASA. Its primary campus is located inside Edwards Air Force Base in California and is considered NASA's premier site for aeronautical rese ...
. A
Lockheed L-1011 The Lockheed L-1011 TriStar, also known as the L-1011 (pronounced "El-ten-eleven") and TriStar, is an American medium-to-long-range, wide-body trijet airliner built by the Lockheed Corporation. It was the third wide-body airliner to enter comme ...
and
McDonnell Douglas DC-10 The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas. The DC-10 was intended to succeed the DC-8 for long-range flights. It first flew on August 29, 1970; it was introduced on August 5, 1971, ...
were also used for testing, and the latter design was directly implemented by McDonnell Douglas on the derivative
MD-11 The McDonnell Douglas MD-11 is an American tri-jet wide-body airliner manufactured by American McDonnell Douglas (MDC) and later by Boeing. Following DC-10 development studies, the MD-11 program was launched on December 30, 1986. Assembly of t ...
, which was rolled out in 1990. In May 1983, a high school student at Bowie High School in Maryland won a grand prize at the 34th
International Science and Engineering Fair The Regeneron International Science and Engineering Fair (ISEF) is an annual science fair in the United States. It is owned and administered by the Society for Science, a 501(c)(3) non-profit organization based in Washington, D.C. Each May, more tha ...
in
Albuquerque, New Mexico Albuquerque ( ; ), ; kee, Arawageeki; tow, Vakêêke; zun, Alo:ke:k'ya; apj, Gołgéeki'yé. abbreviated ABQ, is the most populous city in the U.S. state of New Mexico. Its nicknames, The Duke City and Burque, both reference its founding in ...
for the result of his research on wingtip devices to reduce drag. The same month, he filed a U.S. patent for "wingtip airfoils", published in 1986.


Applications


NASA

NASA's most notable application of wingtip devices is on the
Boeing 747 The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2022. After introducing the 707 in October 1958, Pan Am wanted a jet times its size, t ...
Shuttle Carrier Aircraft The Shuttle Carrier Aircraft (SCA) are two extensively modified Boeing 747 airliners that NASA used to transport Space Shuttle orbiters. One (N905NA) is a 747-100 model, while the other (N911NA) is a short range 747-100SR. The SCAs were used t ...
. Located on the 747's horizontal stabilizers, the devices increase the tailplane's effectiveness under the weight of the
Space Shuttle orbiter The Space Shuttle orbiter is the spaceplane component of the Space Shuttle, a partially reusable orbital spacecraft system that was part of the discontinued Space Shuttle program. Operated from 1977 to 2011 by NASA, the U.S. space agency, thi ...
, though these were more for directional stability than for drag reduction.


Business aircraft

Learjet exhibited the prototype
Learjet 28 The Learjet 28 is an American eight-to-ten-seat (two crew and six to eight passengers), twin-engine, high-speed business jet, intended to be the successor to the Learjet 25. The Learjet 29 is identical except for the addition of a long-range fuel ...
at the 1977
National Business Aviation Association The National Business Aviation Association (NBAA) is a non-profit, 501(c)(6) organization based in Washington, DC, United States. NBAA’s mission, according to the non-profit data and transparency organization GuideStar, is: “to foster an en ...
convention. It employed the first winglets ever used on a production aircraft, either civilian or military. Learjet developed the winglet design without NASA assistance. Although the Model 28 was intended to be a prototype experimental aircraft, performance was such that it resulted in a production commitment from Learjet. Flight tests showed that the winglets increased range by about 6.5 percent and improved directional stability. Learjet's application of winglets to production aircraft continued with newer models including the
Learjet 55 The Learjet 55 "Longhorn" is an American business jet manufactured by Learjet. Development and design The Learjet 50 series was first announced at the 1977 Paris air show with larger cabins than the existing Learjets. The series was to have thre ...
, 31, 60, 45, and Learjet 40.
Gulfstream Aerospace Gulfstream Aerospace Corporation is an American aircraft company and a wholly owned subsidiary of General Dynamics. Gulfstream designs, develops, manufactures, markets, and services business jet aircraft. Gulfstream has produced more than 2,000 ...
explored winglets in the late 1970s and incorporated winglets in the
Gulfstream III The Gulfstream III, a business jet produced by Gulfstream Aerospace, is an improved variant of the Grumman Gulfstream II. Design and development The Gulfstream III was built at Savannah, Georgia, in the United States and was designed as an im ...
,
Gulfstream IV The Gulfstream IV (or G-IV or GIV) and derivatives are a family of twinjet aircraft, mainly for private or business use. They were designed and built by Gulfstream Aerospace, a General Dynamics company based in Savannah, Georgia, United State ...
and
Gulfstream V The Gulfstream V (Model GV, pronounced "G-five") is a long-range, large business jet aircraft produced by Gulfstream Aerospace, derived from the previous Gulfstream IV. It flies up to , up to and has a range. It typically accommodates four cr ...
. The Gulfstream V
range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...
of allows nonstop routes such as New York–Tokyo, it holds over 70 world and national flight records. The Rutan combined winglets-vertical stabilizer appeared on his
Beechcraft Starship The Beechcraft Starship is a twin-turboprop six- to eight-passenger pressurized business aircraft produced by Beech Aircraft Corporation. Development Development of the Starship began in 1979 when Beech decided to explore designs for a succe ...
business aircraft design that first flew in 1986. Winglets are also applied to other business aircraft, reducing take-off distance to operate from smaller airports, and allowing higher cruise altitudes. Along winglets on new designs, aftermarket vendors developed retrofits. Winglet Technology, LLC of
Wichita, Kansas Wichita ( ) is the largest city in the U.S. state of Kansas and the county seat of Sedgwick County, Kansas, Sedgwick County. As of the 2020 United States census, 2020 census, the population of the city was 397,532. The Wichita metro area had ...
should have tested its elliptical winglets designed to increase
payload-range Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...
on
hot and high In aviation, hot and high is a condition of low air density due to high ambient temperature and high airport elevation. Air density decreases with increasing temperature and altitude. The lower air density reduces the power output from the airc ...
departures to retrofit the
Citation X The Cessna Citation X is an American business jet produced by Cessna and part of the Citation family. Announced at the October 1990 NBAA convention, the Model 750 made its maiden flight on December 21, 1993, received its type certification on ...
.


Experimental

Conventional winglets were fitted to Rutan's
Rutan Voyager The Rutan Model 76 Voyager was the first aircraft to fly around the world without stopping or refueling. It was piloted by Dick Rutan and Jeana Yeager. The flight took off from Edwards Air Force Base's 15,000 foot (4,600 m) runway in the Mojav ...
, the first aircraft to circumnavigate the world without refueling in 1986. The aircraft's wingtips were damaged, however, when they dragged along the runway during takeoff, removing about from each wingtip, so the flight was made without benefit of winglets.


Airliner fuel efficiency

The average commercial jet sees a 4-6 percent increase in fuel efficiency and as much as a 6% decrease in in-flight noise from the use of winglets. Actual fuel savings and the related carbon output can vary significantly by plane, route and flight conditions.


Wingtip fence

A wingtip fence refers to the winglets including surfaces extending both above and below the wingtip, as described in Whitcomb's early research. Both surfaces are shorter than or equivalent to a winglet possessing similar aerodynamic benefits. The
Airbus A310-300 The Airbus A310 is a wide-body aircraft, designed and manufactured by Airbus Industrie, then a consortium of European aerospace manufacturers. Airbus had identified a demand for an aircraft smaller than the A300, the first twin-jet wide-bod ...
was the first airliner with wingtip fences in 1985. Other Airbus models followed with the A300-600, the A320ceo, and the
A380 The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was annou ...
. Other Airbus models including the
Airbus A320 Enhanced The Airbus A320 family is a series of Narrow-body aircraft, narrow-body airliners developed and produced by Airbus. The A320 was launched in March 1984, Maiden flight, first flew on 22 February 1987, and was introduced in April 1988 by Air F ...
,
A320neo The Airbus A320neo family is a development of the A320 family of narrow-body airliners produced by Airbus. The A320neo family (''neo'' for "new engine option") is based on the previous A319, A320 and A321 ( enhanced variant), which was then ren ...
,
A350 The Airbus A350 is a long-range, wide-body twin-engine jet airliner developed and produced by Airbus. The first A350 design proposed by Airbus in 2004, in response to the Boeing 787 Dreamliner, would have been a development of the A330 w ...
and
A330neo The Airbus A330neo ("neo" for " New Engine Option") is a wide-body airliner developed by Airbus from the Airbus A330 (now A330''ceo'' – "Current Engine Option"). A new version with modern engines comparable with those developed for the Boei ...
have blended winglets rather than wingtip fences. The
Antonov An-148 The Antonov An-148 ( ua, Антонов Ан-148) is a regional jet designed and built by Antonov of Ukraine. Development of the aircraft was started in the 1990s, and its maiden flight took place on 17 December 2004. The aircraft completed its ...
uses wingtip fences.


Canted winglets

Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and product ...
announced a new version of the 747, the
747-400 The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting ...
, in 1985, with an extended range and capacity, using a combination of winglets and increased span to carry the additional load. The winglets increased the 747-400's range by 3.5% over the 747-300, which is otherwise aerodynamically identical but has no winglets. Winglets are preferred for Boeing derivative designs based on existing platforms, because they allow maximum re-use of existing components. Newer designs are favoring increased span, other wingtip devices or a combination of both, whenever possible. The
Ilyushin Il-96 The Ilyushin Il-96 (russian: Илью́шин Ил-96) is a Russian quadjet long-haul wide-body airliner designed by Ilyushin in the former Soviet Union and manufactured by the Voronezh Aircraft Production Association in Russia. It is powered by ...
was the first Russian and modern jet to feature winglets in 1988. The
Bombardier CRJ-100 The Bombardier CRJ100 and CRJ200 (previously Canadair CRJ100 and CRJ200) is a regional jet designed and manufactured by Bombardier Aerospace between 1991 and 2006, the first of the Bombardier CRJ family. The ''Canadair Regional Jet'' (CRJ) pr ...
/200 was the first regional airliner to feature winglets in 1992. The
A340 The Airbus A340 is a long-range, wide-body passenger airliner that was developed and produced by Airbus. In the mid-1970s, Airbus conceived several derivatives of the A300, its first airliner, and developed the A340 quadjet in parallel with ...
/
A330 The Airbus A330 is a wide-body aircraft developed and produced by Airbus. Airbus conceived several derivatives of the A300, its first airliner in the mid-1970s. Then the company began development on the A330 twinjet in parallel with the A340 ...
followed with canted winglets in 1993/1994. The
Tupolev Tu-204 The Tupolev Tu-204 (russian: Туполев Ту-204) is a twin-engined medium-range narrow-body jet airliner capable of carrying 210 passengers, designed by Tupolev and produced by Aviastar-SP and Kazan Aircraft Production Association. First ...
was the first narrowbody aircraft to feature winglets in 1994. The
Airbus A220 The Airbus A220 is a family of five-abreast narrow-body airliners by Airbus Canada Limited Partnership. It was originally designed by Bombardier and had two years in service as the Bombardier CSeries. The program was launched on 13 July 2 ...
(née CSeries), from 2016, has canted winglets.


Blended winglets

A blended winglet is attached to the wing with a smooth curve instead of a sharp angle and is intended to reduce
interference drag Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extra ...
at the wing/winglet junction. A sharp interior angle in this region can interact with the
boundary layer In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a no-slip boundary condi ...
flow causing a drag inducing vortex, negating some of the benefit of the winglet.
Seattle Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest regio ...
-based
Aviation Partners Aviation Partners Inc. (API) is a Seattle-based private corporation that specializes in performance-enhancing winglet systems. The corporation was founded in 1991 and is owned by The Washington Companies. History API was founded in 1991 by Joe Cl ...
develops blended winglets as retrofits for the
Gulfstream II The Gulfstream II (G-II) is an American twin engine business jet designed and built by Grumman and then in succession, Grumman American and finally Gulfstream American. Its Grumman model number is G-1159 and its US military designation is C-11A. ...
,
Hawker 800 The Hawker 800 is a mid-size twinjet corporate aircraft. It is a development of the British Aerospace BAe 125, and was assembled by Hawker Beechcraft. Development In April 1981, the British Aerospace board sanctioned the programme to improve ...
and the
Falcon 2000 The Dassault Falcon 2000 is a business jet produced by French Dassault Aviation, a member of its Falcon business jet line. Developed from the Falcon 900 trijet, the smaller twinjet has less range. Development The Falcon 900 fuselage was s ...
. File:Winglet and nav light arp.jpg,
Boeing 747-400 The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting ...
canted winglet File:Lufthansa winglet (14511808755).jpg,
Airbus A320 The Airbus A320 family is a series of Narrow-body aircraft, narrow-body airliners developed and produced by Airbus. The A320 was launched in March 1984, Maiden flight, first flew on 22 February 1987, and was introduced in April 1988 by Air F ...
sharklet File:Delta Air Lines 767-400ER @LHR.jpg, Boeing 767-400ER with raked wingtips File:Wing.slat.600pix.jpg,
Airbus A310 The Airbus A310 is a wide-body aircraft, designed and manufactured by Airbus Industrie, then a consortium of European aerospace manufacturers. Airbus had identified a demand for an aircraft smaller than the A300, the first twin-jet wide-bod ...
-300 wingtip fence
On February 18, 2000, blended winglets were announced as an option for the
Boeing 737-800 The Boeing 737 Next Generation, commonly abbreviated as 737NG, or 737 Next Gen, is a narrow-body aircraft powered by two jet engines and produced by Boeing Commercial Airplanes. Launched in 1993 as the third generation derivative of the Boein ...
; the first shipset was installed on 14 February 2001 and entered revenue service with
Hapag-Lloyd Flug Hapag-Lloyd Flug (between 2005 and 2007 also marketed as ''Hapagfly'') was a German leisure airline headquartered in Langenhagen, Lower Saxony that was originally founded by Hapag-Lloyd and later became a subsidiary of TUI Group. It operated sch ...
on 8 May 2001. The Aviation Partners/Boeing extensions decrease
fuel consumption A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
by 4% for long-range flights and increase range by for the 737-800 or the derivative
Boeing Business Jet Boeing Business Jets (BBJ) are versions of Boeing's jet airliners with modifications to serve the private, head of state and corporate jet market. In 1996, Phil Condit, president of The Boeing Company, and Jack Welch, chairman and CEO of Genera ...
as standard. Also offered for the
737 Classic The Boeing 737 Classic is a series of narrow-body airliners produced by Boeing Commercial Airplanes, the second generation of the Boeing 737 series of aircraft. Development began in 1979 and the first variant, the 737-300, first flew in Febru ...
, many operators have retrofitted their fleets with these for the fuel savings. Aviation Partners Boeing also offers blended winglets for the
757 757 may refer to: * Boeing 757: a narrow-body airliner * AD 757: a year * 757 BC: a year * 757 (number): a number * Area code 757 Image:Area code 757.png, The area colored red indicates the southeast corner of Virginia served by area code 757 po ...
and
767-300ER The Boeing 767 is an American wide-body aircraft developed and manufactured by Boeing Commercial Airplanes. The aircraft was launched as the 7X7 program on July 14, 1978, the prototype first flew on September 26, 1981, and it was certified o ...
. In 2006 Airbus tested two candidate blended winglets, designed by Winglet Technology and Airbus for the
Airbus A320 family The Airbus A320 family is a series of narrow-body airliners developed and produced by Airbus. The A320 was launched in March 1984, first flew on 22 February 1987, and was introduced in April 1988 by Air France. The first member of the famil ...
. In 2009 Airbus launched its "Sharklet" blended winglet, designed to enhance the
payload-range Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...
of its
A320 family The Airbus A320 family is a series of narrow-body airliners developed and produced by Airbus. The A320 was launched in March 1984, first flew on 22 February 1987, and was introduced in April 1988 by Air France. The first member of the famil ...
and reduce fuel burn by up to 4% over longer sectors. This corresponds to an annual CO2 reduction of 700 tonnes per aircraft. The A320s fitted with Sharklets were delivered beginning in 2012. They are used on the
A320neo The Airbus A320neo family is a development of the A320 family of narrow-body airliners produced by Airbus. The A320neo family (''neo'' for "new engine option") is based on the previous A319, A320 and A321 ( enhanced variant), which was then ren ...
, the
A330neo The Airbus A330neo ("neo" for " New Engine Option") is a wide-body airliner developed by Airbus from the Airbus A330 (now A330''ceo'' – "Current Engine Option"). A new version with modern engines comparable with those developed for the Boei ...
and the
A350 The Airbus A350 is a long-range, wide-body twin-engine jet airliner developed and produced by Airbus. The first A350 design proposed by Airbus in 2004, in response to the Boeing 787 Dreamliner, would have been a development of the A330 w ...
. They are also offered as a retrofit option.


Raked wingtip

Raked wingtips, where the tip has a greater
wing sweep A swept wing is a wing that angles either backward or occasionally forward from its root rather than in a straight sideways direction. Swept wings have been flown since the pioneer days of aviation. Wing sweep at high speeds was first investigat ...
than the rest of the wing, are featured on some
Boeing Commercial Airplanes Boeing Commercial Airplanes (BCA) is a division of The Boeing Company. It designs, assembles, markets, and sells jet airliners and business jets ( Boeing Business Jets), and also provides product-related maintenance and training to customers wor ...
to improve
fuel efficiency Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, wh ...
, takeoff and climb performance. Like winglets, they increase the effective
wing aspect ratio In aeronautics, the aspect ratio of a wing is the ratio of its span to its mean chord. It is equal to the square of the wingspan divided by the wing area. Thus, a long, narrow wing has a high aspect ratio, whereas a short, wide wing has a low a ...
and diminish
wingtip vortices Wingtip vortices are circular patterns of rotating air left behind a wing as it generates lift.Clancy, L.J., ''Aerodynamics'', section 5.14 One wingtip vortex trails from the tip of each wing. Wingtip vortices are sometimes named ''trailing'' ...
, decreasing lift-induced drag. In testing by Boeing and NASA, they reduce drag by as much as 5.5%, compared to 3.5% to 4.5% for conventional winglets. While an increase in span would be more effective than a same-length winglet, its
bending moment In solid mechanics, a bending moment is the reaction induced in a structural element when an external force or moment is applied to the element, causing the element to bend. The most common or simplest structural element subjected to bending mome ...
is greater. A winglet gives the performance gain of a span increase but has the bending force of a span increase. Raked wingtips offer several weight-reduction advantages relative to simply extending the conventional main
wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of ...
. At high load-factor structural design conditions, the smaller
chords Chord may refer to: * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord a chord played on a guitar, which has a particular tuning * Chord (geometry), a line segment joining two points on a curve * Chord (as ...
of the wingtip are subjected to less load, and they result in less induced loading on the outboard main wing. Additionally, the leading-edge
sweep Sweep or swept may refer to: Cleaning * Sweep, the action of using a brush to clean * Chimney sweep, a worker who clears ash and soot from chimneys * Street sweeper, a person's occupation, or a machine that cleans streets * Swept quartz, a cleani ...
results in the center of pressure being located farther aft than for simple extensions of the span of conventional main wings. At high load factors, this relative aft location of the center of pressure causes the raked wingtip to be twisted more leading-edge down, reducing the bending moment on the inboard wing. However, the relative aft-movement of the center of pressure accentuates flutter. The short-range Boeing 787-3 would have had a wingspan to fit in ICAO Aerodrome Reference Code D. Its wingspan was decreased by using blended winglets instead of raked wingtips. Raked wingtips are installed on the
Boeing 767 The Boeing 767 is an American wide-body aircraft developed and manufactured by Boeing Commercial Airplanes. The aircraft was launched as the 7X7 program on July 14, 1978, the prototype first flew on September 26, 1981, and it was certified on ...
-400ER (first flight on October 9, 1999), the
Boeing 777 The Boeing 777, commonly referred to as the Triple Seven, is an American long-range wide-body airliner developed and manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet. The 777 was designed to bridge the gap bet ...
-200LR/300ER/Freighter (February 24, 2003), the 737-derived
Boeing P-8 Poseidon The Boeing P-8 Poseidon is an American maritime patrol and reconnaissance aircraft developed and produced by Boeing Defense, Space & Security, and derived from the civilian Boeing 737-800. It was developed for the United States Navy (USN). Th ...
(25 April 2009), the
Boeing 787 The Boeing 787 Dreamliner is an American wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, ...
(December 15, 2009), the
Boeing 747-8 The Boeing 747-8 is a wide-body airliner formerly developed by Boeing Commercial Airplanes, and the largest variant of the 747. After introducing the 747-400, Boeing considered larger 747 versions as alternatives to the proposed double-deck ...
(February 8, 2010) and the
Boeing 777X The Boeing 777X is the latest series of the long-range, wide-body, twin-engine jetliners in the Boeing 777 family from Boeing Commercial Airplanes. The 777X features new GE9X engines, new composite wings with folding wingtips, greater cabin ...
. The Embraer
E-jet E2 The Embraer E-Jet E2 family are medium- range jet airliners developed by Embraer, succeeding the original E-Jet. The program was launched at the Paris Air Show in 2013. The first variant, the E190-E2, took its first flight on 23 May 2016 and ...
wing has a raked wingtip.


Split-tip

The
McDonnell Douglas MD-11 The McDonnell Douglas MD-11 is an American tri-jet wide-body airliner manufactured by American McDonnell Douglas (MDC) and later by Boeing. Following DC-10 development studies, the MD-11 program was launched on December 30, 1986. Assembly of t ...
was the first aircraft with split-tip winglets in 1990. For the 737 Next Generation, Aviation Partners Boeing has introduced a similar design to the 737 MAX wingtip device known as the Split Scimitar Winglet, with
United Airlines United Airlines, Inc. (commonly referred to as United), is a major American airline headquartered at the Willis Tower in Chicago, Illinois.
as the launch customer. The
Boeing 737 MAX The Boeing 737 MAX is the fourth generation of the Boeing 737, a narrow-body aircraft, narrow-body airliner manufactured by Boeing Commercial Airplanes (BCA), a division of American company Boeing. It succeeds the Boeing 737 Next Generation (NG ...
uses a new type of wingtip device. Resembling a three-way hybrid between a winglet, wingtip fence, and raked wingtip, Boeing claims that this new design should deliver an additional 1.5% improvement in fuel economy over the 10-12% improvement already expected from the 737 MAX.


Gliders

In 1987,
mechanical engineer Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of ...
Peter Masak Peter C. Masak (August 17, 1957 – May 22, 2004) was an engineer, inventor, and glider pilot. He graduated with a Bachelor of Applied Science degree in mechanical engineering in May 1981 from the University of Waterloo, Ontario, Canada. He ear ...
called on aerodynamicist
Mark D. Maughmer Mark D. Maughmer (born January 18, 1950) is a professor of Aerospace Engineering in the Department of Aerospace Engineering at The Pennsylvania State University. He is a widely published author known throughout the world as one of the leading aero ...
, an associate professor of aerospace engineering at the
Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsylvan ...
, about designing winglets to improve performance on his wingspan racing
sailplane A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...
. Others had attempted to apply Whitcomb's winglets to gliders before, and they did improve climb performance, but this did not offset the parasitic drag penalty in high-speed cruise. Masak was convinced it was possible to overcome this hurdle. By trial and error, they ultimately developed successful winglet designs for
gliding competitions Some of the pilots in the sport of gliding take part in gliding competitions. These are usually racing competitions, but there are also aerobatic contests and on-line league tables. History of competitions In the early days, the main goal wa ...
, using a new PSU–90–125
airfoil An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine. ...
, designed by Maughmer specifically for the winglet application. At the 1991
World Gliding Championships The World Gliding Championships (WGC) is a gliding competition held every two years or so by the FAI Gliding Commission. The dates are not always exactly two years apart, often because the contests are sometimes held in the summer in the Southern ...
in
Uvalde, Texas Uvalde is a city and the county seat of Uvalde County, Texas, United States. The population was 15,217 at the 2020 census. Uvalde is located in the Texas Hill Country, west of downtown San Antonio and east of the Mexico–United States bord ...
, the trophy for the highest speed went to a winglet-equipped 15-meter class limited wingspan glider, exceeding the highest speed in the unlimited span Open Class, an exceptional result. Masak went on to win the 1993 U.S. 15 Meter Nationals gliding competition, using winglets on his prototype
Masak Scimitar The Masak Scimitar was an American mid-wing, single-seat glider that was designed and constructed by Peter Masak. It first flew in 1995. The aircraft was destroyed and the designer killed in a soaring accident on 22 May 2004. Design and deve ...
. The Masak winglets were originally retrofitted to production sailplanes, but within 10 years of their introduction, most high-performance gliders were equipped from the factory with winglets or other wingtip devices. It took over a decade for winglets to first appear on a production airliner, the original application that was the focus of the NASA development. Yet, once the advantages of winglets were proven in competition, adoption was swift with gliders. The point difference between the winner and the runner-up in soaring competition is often less than one percent, so even a small improvement in efficiency is a significant competitive advantage. Many non-competition pilots fitted winglets for handling benefits such as increased
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