![RNZAF Mirage III PITCH BLACK 84 1](https://upload.wikimedia.org/wikipedia/commons/f/f9/RNZAF_Mirage_III_PITCH_BLACK_84_1.JPEG)
A delta wing is a
wing
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...
shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter
delta
Delta commonly refers to:
* Delta (letter) (Δ or δ), a letter of the Greek alphabet
* River delta, at a river mouth
* D ( NATO phonetic alphabet: "Delta")
* Delta Air Lines, US
* Delta variant of SARS-CoV-2 that causes COVID-19
Delta may also ...
(Δ).
Although long studied, it did not find significant applications until the
Jet Age
The Jet Age is a period in the history of aviation defined by the advent of aircraft powered by jet turbine engines, and by the social change this brought about.
Jet airliners were able to fly much higher, faster, and farther than older pisto ...
, when it proved suitable for high-speed
subsonic and
supersonic flight. At the other end of the speed scale, the
Rogallo flexible wing proved a practical design for the
hang glider
Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame cover ...
and other
ultralight aircraft. The delta wing form has unique aerodynamic characteristics and structural advantages. Many design variations have evolved over the years, with and without additional stabilising surfaces.
General characteristics
Structure
The long root chord of the delta wing and minimal structure outboard make it structurally efficient. It can be built stronger, stiffer and at the same time lighter than a
swept wing of equivalent lifting capability. Because of this it is easy and relatively inexpensive to build – a substantial factor in the success of the
MiG-21
The Mikoyan-Gurevich MiG-21 (russian: Микоян и Гуревич МиГ-21; NATO reporting name: Fishbed) is a supersonic jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. Its nickn ...
and
Mirage aircraft series.
Its long root chord also allows a deeper structure for a given aerofoil section, providing more internal volume for fuel and other storage without a significant increase in drag. However, on supersonic designs the opportunity is often taken to use a thinner aerofoil instead, in order to actually reduce drag.
Aerodynamics
Low-speed flight and vortex lift
Like any wing, at low speeds a delta wing requires a high
angle of attack to maintain lift at low speeds. At a sufficiently high angle the wing exhibits
flow separation
In fluid dynamics, flow separation or boundary layer separation is the detachment of a boundary layer from a surface into a wake.
A boundary layer exists whenever there is relative movement between a fluid and a solid surface with viscous f ...
, together with an associated high drag.
Ordinarily, this flow separation leads to a loss of lift known as the
stall. However for a sharply-swept delta wing, as air spills up round the leading edge it flows inwards to generate a characteristic
vortex
In fluid dynamics, a vortex ( : vortices or vortexes) is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved. Vortices form in stirred fluids, and may be observed in smoke rings, whirlpools in ...
pattern over the upper surface. The lower extremity of this vortex remains attached to the surface and also accelerates the airflow, maintaining lift. For intermediate sweep angles, a retractable "moustache" or fixed
leading-edge root extension
A leading-edge extension (LEX) is a small extension to an aircraft wing surface, forward of the leading edge. The primary reason for adding an extension is to improve the airflow at high angles of attack and low airspeeds, to improve handling a ...
(LERX) may be added to encourage and stabilise vortex formation. The ogee or "wineglass" double-curve, seen for example on
Concorde
The Aérospatiale/BAC Concorde () is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC).
Studies started in 1954, and France an ...
, incorporates this forward extension into the profile of the wing.
In this condition, the centre of lift approximates to the centre of the area covered by the vortex.
Subsonic flight
In the subsonic regime, the behaviour of a delta wing is generally similar to that of a swept wing. A characteristic sideways element to the airflow develops. In this condition, lift is maximised along the leading edge of the wing, where the air is turned most sharply to follow its contours. Especially for a slender delta, the centre of lift approximates to halfway back along the leading edge.
The sideways effect may be countered through the use of leading-edge slots, wing fences and related devices.
Transonic and low-supersonic flight
![194th Fighter-Interceptor Squadron - Convair F-106A-135-CO Delta Dart 59-0136](https://upload.wikimedia.org/wikipedia/commons/e/e4/194th_Fighter-Interceptor_Squadron_-_Convair_F-106A-135-CO_Delta_Dart_59-0136.jpg)
With a large enough angle of rearward sweep, in the
transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transoni ...
to low
supersonic speed range the wing's leading edge remains behind the
shock wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...
boundary or
shock cone
Inlet cones (sometimes called shock cones or inlet centerbodies) are a component of some supersonic aircraft and missiles. They are primarily used on ramjets, such as the D-21 Tagboard and Lockheed X-7. Some turbojet aircraft including the Su-7 ...
created by the leading edge root.
This allows air below the leading edge to flow out, up and around it, then back inwards creating a sideways flow pattern similar to subsonic flow. The lift distribution and other aerodynamic characteristics are strongly influenced by this sideways flow.
[Mason, Chap. 10, Pages 9–12.]
The rearward sweep angle lowers the airspeed normal to the leading edge of the wing, thereby allowing the aircraft to fly at high
subsonic, transonic, or supersonic speed, while the subsonic lifting characteristics of the airflow over the wing are maintained.
Within this flight regime, drooping the leading edge within the shock cone increases lift but not drag. Such conical leading edge droop was introduced on the production
Convair F-102A Delta Dagger
The Convair F-102 Delta Dagger was an American interceptor aircraft designed and manufactured by Convair.
Built as part of the backbone of the United States Air Force's air defenses in the late 1950s, it entered service in 1956. Its main purpo ...
at the same time that the prototype design was reworked to include
area-ruling. It also appeared on Convair's next two deltas, the
F-106 Delta Dart
The Convair F-106 Delta Dart was the primary all-weather interceptor aircraft of the United States Air Force from the 1960s through to the 1980s. Designed as the so-called "Ultimate Interceptor", it proved to be the last specialist interceptor ...
and
B-58 Hustler
The Convair B-58 Hustler, designed and produced by American aircraft manufacturer Convair, was the first operational bomber capable of Mach 2 flight.
The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air ...
.
High-speed supersonic waveriding
At high supersonic speeds, the shock cone from the leading edge root angles further back to lie along the wing surface behind the leading edge. It is no longer possible for the sideways flow to occur and the aerodynamic characteristics change considerably.
It is in this flight regime that the
waverider
A waverider is a hypersonic aircraft design that improves its supersonic lift-to-drag ratio by using the shock waves being generated by its own flight as a lifting surface, a phenomenon known as compression lift.
The waverider remains a we ...
design, as used on the
North American XB-70 Valkyrie
The North American Aviation XB-70 Valkyrie was the prototype version of the planned B-70 nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed in the late 1950s by North Ame ...
, becomes practicable. Here, a shock body beneath the wing creates an attached shockwave and the high pressure associated with the wave provides significant lift without increasing drag.
Design variations
![Concorde on Bristol](https://upload.wikimedia.org/wikipedia/commons/0/06/Concorde_on_Bristol.jpg)
Variants of the delta wing plan offer improvements to the basic configuration.
Cropped delta – tip is cut off. This helps maintain lift outboard and reduce wingtip flow separation (stalling) at high angles of attack. Most deltas are cropped to at least some degree.
In the compound delta, double delta or cranked arrow, the leading edge is not straight. Typically the inboard section has increased sweepback, creating a controlled high-lift vortex without the need for a foreplane. Examples include the
Saab Draken
The Saab 35 Draken (; 'The Kite' or 'The Dragon') is a Sweden, Swedish interceptor aircraft, fighter-interceptor developed and manufactured by Saab AB, Svenska Aeroplan Aktiebolaget (Saab AB, SAAB) between 1955 and 1974. Development of the Saab 35 ...
fighter and the experimental
General Dynamics F-16XL
The General Dynamics F-16XL is a derivative of the F-16 Fighting Falcon, with a cranked-arrow delta wing. It was originally conceived as a technology demonstrator, later entered in the United States Air Force's (USAF) Enhanced Tactical Fighte ...
. The ogee delta (or ogival delta) used on the Anglo-French
Concorde
The Aérospatiale/BAC Concorde () is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC).
Studies started in 1954, and France an ...
Mach 2
airliner is similar, but with the two sections and cropped wingtip merged into a smooth
ogee
An ogee ( ) is the name given to objects, elements, and curves—often seen in architecture and building trades—that have been variously described as serpentine-, extended S-, or sigmoid-shaped. Ogees consist of a "double curve", the combinat ...
curve.
Tailed delta – adds a conventional tailplane (with horizontal tail surfaces), to improve handling. Common on Soviet types such as the
Mikoyan-Gurevich MiG-21.
Canard delta – Many modern fighter aircraft, such as the
JAS 39 Gripen
The Saab JAS 39 Gripen (; English: ''griffin'') is a light single-engine multirole fighter aircraft manufactured by the Swedish aerospace and defense company Saab AB. The Gripen has a delta wing and canard configuration with relaxed stabilit ...
, the
Eurofighter Typhoon
The Eurofighter Typhoon is a European multinational twin-engine, canard delta wing, multirole fighter. The Typhoon was designed originally as an air-superiority fighter and is manufactured by a consortium of Airbus, BAE Systems and Leonardo ...
and the
Dassault Rafale
The Dassault Rafale (, literally meaning "gust of wind", and "burst of fire" in a more military sense) is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation. Equipped with a wide range ...
use a combination of
canard foreplanes and a delta wing.
Tailless delta
![Saab Draken](https://upload.wikimedia.org/wikipedia/commons/e/e5/Saab_Draken.jpg)
Like other
tailless aircraft
In aeronautics, a tailless aircraft is an aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin (vertical stabilizer), and/or vertical rudder.
Theoretical advantages of the ...
, the tailless delta wing is not suited to high wing loadings and requires a large wing area for a given aircraft weight. The most efficient aerofoils are unstable in pitch and the tailless type must use a less efficient design and therefore a bigger wing. Techniques used include:
* Using a less efficient aerofoil which is inherently stable, such as a symmetrical form with zero camber, or even reflex camber near the trailing edge,
* Using the rear part of the wing as a lightly- or even negatively-loaded horizontal stabiliser:
**Twisting the outer leading edge down to reduce the incidence of the wing tip, which is behind the main centre of lift. This also improves stall characteristics and can benefit supersonic cruise in other ways.
**Moving the centre of mass forwards and trimming the elevator to exert a balancing downforce. In the extreme, this reduces the craft's ability to pitch its nose up for takeoff and landing.
The main advantages of the tailless delta are structural simplicity and light weight, combined with low aerodynamic drag. These properties helped to make the
Dassault Mirage III
The Dassault Mirage III () is a family of single/dual-seat, single-engine, fighter aircraft developed and manufactured by French aircraft company Dassault Aviation. It was the first Western European combat aircraft to exceed Mach number, Mach 2 ...
one of the most widely manufactured supersonic fighters of all time.
Tailed delta
A conventional tail stabiliser allows the main wing to be optimised for lift and therefore to be smaller and more highly loaded. Development of aircraft equipped with this configuration can be traced back to the late 1940s.
When used with a T-tail, as in the
Gloster Javelin
The Gloster Javelin is a twin-engined T-tailed delta-wing subsonic night and all-weather interceptor aircraft that served with Britain's Royal Air Force from the mid-1950s until the late 1960s. The last aircraft design to bear the Gloster name ...
, like other wings a delta wing can give rise to a "
deep stall
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 486. Aviation Supplies & Academics, 1997. This occurs when t ...
" in which the high angle of attack at the stall causes the turbulent wake of the stalled wing to envelope the tail. This makes the elevator ineffective and the airplane cannot recover from the stall. In the case of the Javelin, a
stall warning device was developed and implemented for the Javelin following the early loss of an aircraft to such conditions.
[Patridge 1967, p. 6.] Gloster's design team had reportedly opted to use a tailed delta configuration out of necessity, seeking to achieve effective manoeuvrability at relatively high speeds for the era while also requiring suitable controllability when being flown at the slower landing speeds desired.
Canard delta
![Eurofighter 9803 2](https://upload.wikimedia.org/wikipedia/commons/b/bc/Eurofighter_9803_2.jpg)
A lifting-canard delta can offer a smaller shift in the center of lift with increasing Mach number compared to a conventional tail configuration.
An unloaded or free-floating canard can allow a safe recovery from a high angle of attack. Depending on its design, a canard surface may increase or decrease longitudinal stability of the aircraft.
A canard delta foreplane creates its own trailing vortex. If this vortex interferes with the vortex of the main delta wing, this can adversely affect the airflow over the wing and cause unwanted and even dangerous behaviour. In the close-coupled configuration, the canard vortex couples with the main vortex to enhance its benefits and maintain controlled airflow through a wide range of speeds and angles of attack. This allows both improved manoeuvrability and lower stalling speeds, but the presence of the foreplane can increase drag at supersonic speeds and hence reduce the aircraft's maximum speed.
History
Early research
Triangular stabilizing fins for rockets were described as early as 1529-1556 by the Austrian military engineer
Conrad Haas
Conrad Haas (1509–1576) was an Austrian or Transylvanian Saxon military engineer.
He was a pioneer of rocket propulsion. His designs include a three-stage rocket and a manned rocket.
Haas was perhaps born in Dornbach (now part of Hernal ...
and in the 17th century by the Polish-Lithuanian military engineer
Kazimierz Siemienowicz
Kazimierz Siemienowicz ( la, Casimirus Siemienowicz, lt, Kazimieras Simonavičius; born 1600 – 1651) was a general of artillery, gunsmith, military engineer, and one of pioneers of rocketry. Born in the Raseiniai region of the Grand Duchy ...
. However, a true lifting wing in delta form did not appear until 1867, when it was
patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
ed by J.W. Butler and E. Edwards in a design for a low-aspect-ratio, dart-shaped rocket-propelled aeroplane. This was followed by various other proposals, such as a biplane version by Butler and Edwards, and a jet-propelled version by the Russian
Nicholas de Telescheff.
In 1909, British aeronautical pioneer
J. W. Dunne patented his tailless stable aircraft with conical wing development. The patent included a broad-span biconical delta, with each side bulging upwards towards the rear in a manner characteristic of the modern
Rogallo wing
The Rogallo wing is a flexible type of wing. In 1948, Francis Rogallo, a NASA engineer, and his wife Gertrude Rogallo, invented a self-inflating flexible wing they called the Parawing, also known after them as the "Rogallo Wing" and flexible wing ...
. During the following year, in America U.G. Lee and W.A. Darrah patented a similar biconical delta winged aeroplane with an explicitly rigid wing. It also incorporated a proposal for a flight control system and covered both gliding and powered flight.
[Woodhams, Mark and Henderson, Graeme; "Did we really fly Rogallo wings?", ''Skywings'', June 2010.] None of these early designs is known to have successfully flown although, in 1904, Lavezzani's hang glider featuring independent left and right triangular wings had left the ground, and Dunne's other tailless swept designs based on the same principle would fly.
The practical delta wing was pioneered by German aeronautical designer
Alexander Lippisch in the 1930s, using a thick cantilever wing without any tail. His first such designs, for which he coined the name "Delta", used a very gentle angle so that the wing appeared almost straight and the wing tips had to be cropped sharply (see below). His first such delta flew in 1931, followed by four successively improved examples.
[.] These prototypes were not easy to handle at low speed and none saw widespread use.
Subsonic thick wing
![Vulcan](https://upload.wikimedia.org/wikipedia/commons/6/67/Vulcan.delta.arp.jpg)
During the latter years of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
, Alexander Lippisch refined his ideas on the high-speed delta, substantially increasing the sweepback of the wing's leading edge. An experimental glider, the
DM-1, was built to test the aerodynamics of the proposed
P.13a high-speed
interceptor
Interceptor may refer to:
Vehicles
* Interceptor aircraft (or simply "interceptor"), a type of point defense fighter aircraft designed specifically to intercept and destroy enemy aircraft
* Ford Crown Victoria Police Interceptor, a police car
* ...
. Following the end of hostilities, the DM-1 was completed on behalf of the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
and the shipped to
Langley Field Langley may refer to:
People
* Langley (surname), a common English surname, including a list of notable people with the name
* Dawn Langley Simmons (1922–2000), English author and biographer
* Elizabeth Langley (born 1933), Canadian perfo ...
in
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
for examination by
NACA
The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets ...
(National Advisory Committee for Aeronautics, forerunner of today's
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
) It underwent significant alterations in the US, typically to lower its drag, resulting in the replacement of its large vertical stabilizer with a smaller and more conventional counterpart, along with a normal cockpit canopy taken from a
Lockheed P-80 Shooting Star
The Lockheed P-80 Shooting Star was the first jet fighter used operationally by the United States Army Air Forces (USAAF) during World War II. Designed and built by Lockheed in 1943 and delivered just 143 days from the start of design, prod ...
.
The work of French designer
Nicolas Roland Payen Nicolas Roland Payen (2 February 1914 in Athis-Mons, France – 8 December 2004) was a French aeronautical engineer
Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two ...
somewhat paralleled that of Lippisch. During the 1930s, he had developed a tandem delta configuration with a straight fore wing and steep delta aft wing. The outbreak of the Second World War brought a halt to flight testing of the
Pa-22, although work continued for a time after the project garnered German attention.
During the
postwar
In Western usage, the phrase post-war era (or postwar era) usually refers to the time since the end of World War II. More broadly, a post-war period (or postwar period) is the interval immediately following the end of a war. A post-war period ...
era, Payen flew an experimental tailless delta jet, the
Pa.49, in 1954, as well as the tailless pusher-configuration
Arbalète series from 1965. Further derivatives based on Payen's work were proposed but ultimately went undeveloped.
Following the war, the British developed a number of subsonic jet aircraft that harnessed data gathered from Lippisch's work. One such aircraft, the
Avro 707 research aircraft, made its first flight in 1949. British military aircraft such as the
Avro Vulcan
The Avro Vulcan (later Hawker Siddeley Vulcan from July 1963) is a jet-powered, tailless, delta-wing, high-altitude, strategic bomber, which was operated by the Royal Air Force (RAF) from 1956 until 1984. Aircraft manufacturer A.V. Roe an ...
(a
strategic bomber) and
Gloster Javelin
The Gloster Javelin is a twin-engined T-tailed delta-wing subsonic night and all-weather interceptor aircraft that served with Britain's Royal Air Force from the mid-1950s until the late 1960s. The last aircraft design to bear the Gloster name ...
(an all-weather fighter) were among the first delta-equipped aircraft to enter production. Whereas the Vulcan was a classic tailless design, the Javelin incorporated a tailplane in order to improve low-speed handling and high-speed manoeuvrability, as well as to allow a greater
centre of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...
range. Gloster proposed a refinement of the Javelin that would have, amongst other changes, decreased wing thickness in order to achieve supersonic speeds of up to Mach 1.6.
Supersonic thin wing
![SSSR-MiG-21SM(DN-ST-82-10891)](https://upload.wikimedia.org/wikipedia/commons/4/4a/SSSR-MiG-21SM%28DN-ST-82-10891%29.jpg)
The American aerodynamicist Robert T. Jones, who worked at NACA during the Second World War, developed the theory of the thin delta wing for supersonic flight. First published in January 1945, his approach contrasted with that of Lippisch on thick delta wings. The thin delta wing first flew on the
Convair XF-92
The Convair XF-92 (re-designated from XP-92 in 1948) was an American, delta wing, first-generation jet prototype. Originally conceived as a point-defence interceptor, the design was later used purely for experimental purposes and only one w ...
in 1948, making it the first delta-winged jet plane to fly. It provided a successful basis for all practical supersonic deltas and became widely adopted.
During the late 1940s, the British aircraft manufacturer
Fairey Aviation
The Fairey Aviation Company Limited was a British aircraft manufacturer of the first half of the 20th century based in Hayes in Middlesex and Heaton Chapel and RAF Ringway in Cheshire. Notable for the design of a number of important military a ...
became interested in the delta wing,
[Wood 1975, p. 73.] its proposals leading to the experimental
Fairey Delta 1
The Fairey Delta 1 (FD1) was a research aircraft developed and produced by British aircraft manufacturer Fairey Aviation. It holds the distinction of being the first British-designed aircraft to be furnished with a delta wing.
Initially referr ...
being produced to
Air Ministry Specification E.10/47.
[Wood 1975, p. 74.] A subsequent experimental aircraft, the
Fairey Delta 2
The Fairey Delta 2 or FD2 (internal designation Type V within Fairey) is a British supersonic research aircraft that was produced by the Fairey Aviation Company in response to a specification from the Ministry of Supply for a specialised aircra ...
,
["Individual History: Fairey FD-2 Delta WG777/7986M."](_blank)
''Royal Air Force Museum'', Retrieved: 13 December 2016. proved able to obtain speeds in excess of any other conventional aircraft in existence of that time.
["50 years ago: 16 Mar 1956."](_blank)
''Flight International'', 10 March 2006.[Wood 1975, p. 77.] On 10 March 1956, the Fairey Delta 2 broke the
World Air Speed Record, raising it to 1,132 mph (1,811 km/h) or Mach 1.73.
["Fairey FD2."](_blank)
''Royal Air Force Museum'', Retrieved: 13 December 2016. This achievement exceeded the prior recorded airspeed record by 310 mph, or 37 per cent; never before had the record ever been raised by such a vast margin.
[Wood 1975, p. 79.]
In its original tailless form, the thin delta was used extensively by the American aviation company
Convair
Convair, previously Consolidated Vultee, was an American aircraft manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee Aircraft. In 1953, i ...
and by the French aircraft manufacturer
Dassault Aviation. The supersonic
Convair F-102 Delta Dagger
The Convair F-102 Delta Dagger was an American interceptor aircraft designed and manufactured by Convair.
Built as part of the backbone of the United States Air Force's air defenses in the late 1950s, it entered service in 1956. Its main purpos ...
and transonic
Douglas F4D Skyray
The Douglas F4D Skyray (later redesignated F-6 Skyray) is an American carrier-based fighter/ interceptor built by the Douglas Aircraft Company. Although it was in service for a relatively short time (1956–1964) and never entered combat, it w ...
were two of the first operational jet fighters to feature a tailless delta wing when they entered service in 1956. Dassault's interest in the delta wing produced the
Dassault Mirage Mirage is a name given to several types of jet aircraft designed by the French company Dassault Aviation (formerly Avions Marcel Dassault), some of which were produced in different variants. Most were supersonic fighters with delta wings. The most s ...
family of combat aircraft, especially the highly successful
Mirage III
The Dassault Mirage III () is a family of single/dual-seat, single-engine, fighter aircraft developed and manufactured by French aircraft company Dassault Aviation. It was the first Western European combat aircraft to exceed Mach 2 in horizonta ...
. Amongst other attributes, the Mirage III was the first Western European combat aircraft to exceed Mach 2 in horizontal flight.
["Mirage III."](_blank)
''Dassault Aviation'', 18 December 2015.
The tailed delta configuration was adopted by the
TsAGI
The Central Aerohydrodynamic Institute (also (Zhukovsky) Central Institute of Aerodynamics, russian: Центра́льный аэрогидродинами́ческий институ́т, ЦАГИ, Tsentral'nyy Aerogidrodinamicheskiy Institut, ...
(Central Aero and Hydrodynamic Institute,
Moscow
Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...
), to improve 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 ...
handling, manoeuvrability and centre of gravity range over a pure delta planform. The
Mikoyan-Gurevich MiG-21 ("Fishbed") became the most widely built combat aircraft of the 1970s.
Close-coupled canard
![Saab viggen underside](https://upload.wikimedia.org/wikipedia/commons/2/20/Saab_viggen_underside.jpg)
Through the 1960s, the
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used by ...
aircraft manufacturer
Saab AB developed a close-coupled canard delta configuration, placing a delta foreplane just in front of and above the main delta wing.
Patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
ed in 1963, this configuration was flown for the first time on the company's
Viggen
The Saab 37 Viggen (Swedish for ''"the Bolt"'' or ''"the Tufted Duck"'' ( see name)) is a retired Swedish single-seat, single-engine, short-medium range combat aircraft. Development work on the type was initiated at Saab in 1952 and, followin ...
combat aircraft in 1967. The close coupling modifies the airflow over the wing, most significantly when flying at high angles of attack. In contrast to the classic tail-mounted elevators, the canards add to the total lift as well as stabilising the airflow over the main wing. This enables more extreme manoeuvres, improves low-speed handling and reduces the takeoff run and landing speed. During the 1960s, this configuration was considered to be radical, but Saab's design team judged that it was the optimal approach available for satisfying the conflicting performance demands for the Viggen, which including favourable
STOL performance, supersonic speed, low turbulence sensitivity during low level flight, and efficient lift for subsonic flight.
["1960s."]
''Company History'', Saab. Retrieved 6 March 2016.[Gunston and Gilchrist 1993, p. 244.]
The close-coupled canard has since become common on supersonic fighter aircraft. Notable examples include the multinational
Eurofighter Typhoon
The Eurofighter Typhoon is a European multinational twin-engine, canard delta wing, multirole fighter. The Typhoon was designed originally as an air-superiority fighter and is manufactured by a consortium of Airbus, BAE Systems and Leonardo ...
, France's
Dassault Rafale
The Dassault Rafale (, literally meaning "gust of wind", and "burst of fire" in a more military sense) is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation. Equipped with a wide range ...
, Saab's own
Gripen
The Saab JAS 39 Gripen (; English: ''griffin'') is a light single-engine multirole fighter aircraft manufactured by the Swedish aerospace and defense company Saab AB. The Gripen has a delta wing and canard configuration with relaxed stabilit ...
(a successor to the Viggen) and Israel's
IAI Kfir
, abbreviated , is a Japanese martial art that emphasizes being aware and capable of quickly drawing the sword and responding to sudden attacks.Christensen, Karen and Allen Guttmann et.al (2001) ''International Encyclopedia of Women and Sport ...
. One of the main reasons for its popularity has been the high level of agility in manoeuvring that it is capable of.
[Warwick 1980, p. 1260.][Roskam 2002, p. 206.]
Supersonic transport
When supersonic transport (SST) aircraft were developed, the tailless ogival delta wing was chosen for both the Anglo-French
Concorde
The Aérospatiale/BAC Concorde () is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC).
Studies started in 1954, and France an ...
and the Soviet
Tupolev Tu-144
The Tupolev Tu-144 (russian: Tyполев Ту-144; NATO reporting name: Charger) is a Soviet supersonic passenger airliner designed by Tupolev in operation from 1968 to 1999.
The Tu-144 was the world's first commercial supersonic transport ai ...
, the Tupolev first flying in 1968. While both Concorde and the Tu-144 prototype featured an
ogival delta configuration, production models of the Tu-144 differed by changing to a
double delta
A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (Δ).
Although long studied, it did not find significant applications until the Jet Age, when it proved suitab ...
wing.
[Tupolev Tu-144, Gordon, Komissarov and Rigmant 2015, Schiffer Publishing Ltd, ] The delta wings required these airliners to adopt a higher
angle of attack at low speeds than conventional aircraft; in the case of Concorde, lift was maintained by allowed the formation of large low pressure vortices over the entire upper wing surface. Its typical landing speed was , considerably higher than subsonic airliners. Multiple proposed successors, such as the
Zero Emission Hyper Sonic Transport
The Zero Emission Hyper Sonic Transport or ZEHST is a planned hypersonic passenger jet airliner project by the multinational aerospace conglomerate EADS and the Japanese national space agency JAXA.
On 18 June 2011, the ZEHST concept was unveil ...
ZEHST), have reportedly adopted a similar configuration to that Concorde's basic design, thus the Delta wing remains a likely candidate for future supersonic civil endeavours.
Rogallo flexible wing
![Birdman MJ-5 0002](https://upload.wikimedia.org/wikipedia/commons/e/e1/Birdman_MJ-5_0002.jpeg)
During and after WWII, Francis and Gertrude Rogallo developed the idea of a flexible wing which could be collapsed for storage. Francis saw an application in spacecraft recovery and NASA became interested. In 1961 Ryan flew the
XV-8, an experimental "flying Jeep" or "fleep". The flexible wing chosen for it was a delta and in use it billowed out into a double-cone profile which gave it aerodynamic stability. Although tested but ultimately never used for spacecraft recovery, this design soon became popular for
hang gliders
Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered ...
and
ultra-light aircraft
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with aile ...
and has become known as the Rogallo wing.
See also
*
List of delta-wing aircraft
This is a list of aircraft with delta wings.
, -
, Aérospatiale-BAC Concorde , , UK/France , , Supersonic , , Transport , , 1969 , , Retired , , , , Ogival delta.
, -
, Antonov 'M' Masha , , USSR , , Supersonic , , Fighter , , ...
*
Hermann Behrbohm
Otto ''Hermann'' Bernhard Behrbohm, born 30 October 1907 in Karlsruhe, Grand Duchy of Baden, Imperial Germany; died 12 October 1977 in Fingelsham, Northbourne, Kent, United Kingdom, was a German mathematician active in Sweden and Germany.
H ...
*
Bertil Dillner
Bertil Dillner (12 May 1923 in Lit Jämtland, Sweden – 9 May 2015 in Linköping) was a Swedish aeronautical engineer and aerodynamic expert. He was significant in the development of delta wing aerodynamics and supersonic flight concepts. Dil ...
References
Citations
Bibliography
* Allward, Maurice. ''Postwar Military Aircraft: Gloster Javelin''. Ian Allan, 1999. .
*
*
* Gunston, Bill and Peter Gilchrist. ''Jet Bombers: From the Messerschmitt Me 262 to the Stealth B-2''. Osprey, 1993. .
* Mason W.H
"Configuration Aerodynamics." AOE 4124, Virginia Tech.
*
* Patridge, J. ''The Gloster Javelin 1–6: Number 179.'' Profile Publications, 1967.
*
* Warwick, Graham
''Flight International'', 27 September 1980. pp. 1260–65.
* Roskam, Jan. ''Airplane Design: Layout Design of Cockpit, Fuselage, Wing and Empennage : Cutaways and Inboard Profiles.'' DARcorporation, 2002. .
External links
{{Wiktionary, delta wing
Aircraft wing design
Wing configurations