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55-548: This resemblance, and that Selenia was provided with the technology know-how of the AIM-7 (around 1,000 of which it had produced under licence), has generally led non-Italian press to refer to the Aspide as a Sparrow variant. However, the Aspide had original electronics and warhead, and a new and more powerful engine. Closed-loop hydraulics were also substituted for Sparrow's open-loop type, which gave Aspide better downrange maneuverability. Even

110-468: A broad-span biconical delta, with each side bulging upwards towards the rear in a manner characteristic of the modern Rogallo 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. None of these early designs

165-405: A delta foreplane just in front of and above the main delta wing. Patented in 1963, this configuration was flown for the first time on the company's Viggen 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

220-412: A given aerofoil section. This both enhances its weight-saving characteristic and provides greater internal volume for fuel and other items, 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. Like any wing, at low speeds a delta wing requires a high angle of attack to maintain lift. At

275-443: A shock body beneath the wing creates an attached shockwave and the high pressure associated with the wave provides significant lift without increasing drag. 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

330-406: A sufficiently high angle the wing exhibits flow separation , 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 pattern over the upper surface. The lower extremity of this vortex remains attached to

385-652: A vortex over the wing to control boundary layer spanwise extension, increasing lift and improving resistance to stall. Some of the best-known uses of the dogtooth are in the stabilizer of the F-15 Eagle and the wings of the F-4 Phantom II , F/A-18 Super Hornet , CF-105 Arrow , F-8 Crusader , and the Ilyushin Il-62 . Where the dogtooth is added as an afterthought, as for example on the Hawker Hunter and some variants of

440-421: Is a small fillet , typically roughly triangular in shape, running forward from the leading edge of the wing root to a point along the fuselage. These are often called simply leading-edge extensions (LEX), although they are not the only kind. To avoid ambiguity, this article uses the term LERX. On a modern fighter aircraft , LERXes induce controlled airflow over the wing at high angles of attack , so delaying

495-405: Is a small, sharp zig-zag break in the leading edge of a wing. It is usually used on a swept wing, to generate a vortex flow field to prevent separated flow from progressing outboard at high angle of attack. The effect is the same as a wing fence . It can also be used on straight wings in a drooped leading edge arrangement. Many high-performance aircraft use the dogtooth design, which induces

550-433: Is an aerodynamic surface running spanwise just ahead of the wing leading edge. It creates a leading edge slot between the slat and wing which directs air over the wing surface, helping to maintain smooth airflow at low speeds and high angles of attack . This delays the stall , allowing the aircraft to fly at a higher angle of attack. Slats may be made fixed, or retractable in normal flight to minimize drag . A dogtooth

605-434: 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

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660-513: 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 fighter, the experimental General Dynamics F-16XL , and the Hawker Siddeley HS. 138 VTOL concept. The ogee delta (or ogival delta ) used on

715-476: The Dassault Rafale use a combination of canard foreplanes and a delta wing. Like other tailless aircraft , 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: The main advantages of

770-564: The F-106 Delta Dart and B-58 Hustler . 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 design, as used on the North American XB-70 Valkyrie , becomes practicable. Here,

825-551: The Jet Age , 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 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. The long root chord of

880-550: The LY-60 , and an air-to-air version designated as PL-11 . The rocket engine of the Aspide is produced by Turkish missile manufacturer Roketsan . It weighs about 75 kg and produces 50 kN of thrust for 3.5 s. Cropped 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

935-577: The Pugachev's Cobra , the Cobra Turn and the Kulbit . A long, narrow sideways extension to the fuselage, attached in this position, is an example of a chine . Leading-edge vortex controller (LEVCON) systems are a continuation of leading-edge root extension (LERX) technology, but with actuation that allows the leading edge vortices to be modified without adjusting the aircraft's attitude. Otherwise they operate on

990-494: The Quest Kodiak , the dogtooth is created by adding an extension to the outer section of the leading edge. A leading edge cuff (or wing cuff) is a fixed aerodynamic device employed on fixed-wing aircraft to introduce a sharp discontinuity in the leading edge of the wing in the same way as a dogtooth. It also typically has a slightly drooped leading edge to improve low-speed characteristics. A leading-edge root extension (LERX)

1045-661: The Anglo-French Concorde supersonic airliner is similar, but with the two sections and cropped wingtip merged into a smooth ogee 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 Eurofighter Typhoon and

1100-458: The Javelin following the early loss of an aircraft to such conditions. 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. A lifting-canard delta can offer a smaller shift in

1155-473: The Rogallo wing. 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 and delay the stall. A dog tooth can also improve airflow and reduce drag at higher speeds. A leading-edge slat

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1210-572: 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 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

1265-532: 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 in 1948, making it the first delta-winged jet plane to fly. It provided a successful basis for all practical supersonic deltas and the configuration became widely adopted. During

1320-567: The Soviet Tupolev Tu-144 , 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 wing. 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

1375-525: 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 work of French designer Nicolas Roland Payen 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, similar to that of Causarás. The outbreak of

1430-667: 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. The close-coupled canard has since become common on supersonic fighter aircraft. Notable examples include

1485-578: The airflow separates from the wing surface, thus sustaining lift at very high angles. LERX were first used on the Northrop F-5 "Freedom Fighter" which flew in 1959, and have since become commonplace on many combat aircraft. The F/A-18 Hornet has especially large examples, as does the Sukhoi Su-27 and the CAC/PAC JF-17 Thunder . The Su-27 LERX help make some advanced maneuvers possible, such as

1540-400: 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

1595-426: The centre of the area covered by the vortex. 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

1650-514: The control surfaces are different, replacing the original triangular wings, fixed in the air-to-air and instead foldable in the surface-to-air version, to a newly designed common cropped delta fixed version. A similar design is the UK's Skyflash , which entered service about the same time. The US's own Sparrow fleet also added a monopulse seeker in the AIM-7M versions of 1982. Aspide, in its various versions,

1705-459: The delta wing and minimal area outboard make it structurally efficient. It can be built stronger, stiffer and at the same time lighter than a swept wing of equivalent aspect ratio and lifting capability. Because of this it is easy and relatively inexpensive to build—a substantial factor in the success of the MiG-21 and Mirage aircraft series. Its long root chord also allows a deeper structure for

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1760-517: 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 family of combat aircraft, especially the highly successful Mirage III . Amongst other attributes, the Mirage III was the first Western European combat aircraft to exceed Mach 2 in horizontal flight. The tailed delta configuration

1815-511: The foreplane can increase drag at supersonic speeds and hence reduce the aircraft's maximum speed. Triangular stabilizing fins for rockets were described as early as 1529-1556 by the Austrian military engineer Conrad Haas and in the 17th century by the Polish-Lithuanian military engineer Kazimierz Siemienowicz . However, a true lifting wing in delta form did not appear until 1867, when it

1870-645: The formation of large low pressure vortices over the entire upper wing surface. Its typical landing speed was 170 miles per hour (274 km/h), considerably higher than subsonic airliners. Multiple proposed successors, such as the Zero Emission Hyper Sonic Transport 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. During and after WWII, Francis and Gertrude Rogallo developed

1925-565: 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 and ultra-light aircraft and has become known as

1980-504: The late 1940s, the British aircraft manufacturer Fairey Aviation became interested in the delta wing, its proposals led to the experimental Fairey Delta 1 being produced to Air Ministry Specification E.10/47 . A subsequent experimental aircraft, the Fairey Delta 2 set a new World air speed record on 10 March 1956, achieving 1,132 mph (1,811 km/h) or Mach 1.73. This raised

2035-480: The late 1940s. When used with a T-tail, as in the Gloster Javelin , like other wings a delta wing can give rise to a " deep stall " 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

2090-461: 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. 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

2145-428: The leading edge. The sideways effect also leads to an overall reduction in lift and in some circumstances can also lead to an increase in drag. It may be countered through the use of leading-edge slots, wing fences and related devices. With a large enough angle of rearward sweep, in the transonic to low supersonic speed range the wing's leading edge remains behind the shock wave boundary or shock cone created by

2200-402: 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

2255-507: The missile locally under license. In 1989, China produced its first batch of Aspide Mk.1 missiles using imported parts from Italy. However, due to the EEC arms embargo imposed after the 1989 Tiananmen Square protests and massacre , China was unable to purchase additional Aspide kits. China subsequently developed its own missile family based on the Aspide Mk.1, with surface to air versions designated as

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2310-450: The multinational Eurofighter Typhoon , France's Dassault Rafale , Saab's own Gripen (a successor to the Viggen) and Israel's IAI Kfir . One of the main reasons for its popularity has been the high level of agility in manoeuvring that it is capable of. When supersonic transport (SST) aircraft were developed, the tailless ogival delta wing was chosen for both the Anglo-French Concorde and

2365-444: 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. During the latter years of World War II , Alexander Lippisch refined his ideas on the high-speed delta, substantially increasing

2420-543: The record above 1,000 mph for the first time and broke the previous record by 310 mph, or 37 per cent; never before had the record been raised by such a large margin. In its original tailless form, the thin delta was used extensively by the American aviation company Convair and by the French aircraft manufacturer Dassault Aviation . The supersonic Convair F-102 Delta Dagger and transonic Douglas F4D Skyray were two of

2475-545: The same principles as the LERX system to create lift augmenting leading edge vortices during high angle of attack flight. This system has been incorporated in the Russian Sukhoi Su-57 and Indian HAL LCA Navy . The LEVCONs actuation ability also improves its performance over the LERX system in other areas. When combined with the thrust vectoring controller (TVC), the aircraft controllability at extreme angles of attack

2530-403: The stall and consequent loss of lift. In cruising flight, the effect of the LERX is minimal. However, at high angles of attack, as often encountered in a dogfight or during takeoff and landing, the LERX generates a high-speed vortex that attaches to the top of the wing. The vortex action maintains the attachment of the airflow to the upper-wing surface well past the normal stall point at which

2585-439: 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 to any significant extent. Such conical leading edge droop was introduced on the production Convair F-102A Delta Dagger at the same time that the prototype design was reworked to include area-ruling . It also appeared on Convair's next two deltas,

2640-416: The surface and also accelerates the airflow, maintaining lift. For intermediate sweep angles, a retractable "moustache" or fixed leading-edge root extension (LERX) may be added to encourage and stabilise vortex formation. The ogee or "wineglass" double-curve, seen for example on Concorde , incorporates this forward extension into the profile of the wing. In this condition, the centre of lift approximates to

2695-642: 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 . Following the end of hostilities, the DM-1 was completed on behalf of the United States and the shipped to Langley Field in Virginia for examination by NACA (National Advisory Committee for Aeronautics, forerunner of today's NASA ) It underwent significant alterations in

2750-496: The tailless delta are structural simplicity and light weight, combined with low aerodynamic drag. These properties helped to make the Dassault Mirage III one of the most widely manufactured supersonic fighters of all time. 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

2805-555: 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 (a strategic bomber ) and Gloster Javelin (an all-weather fighter) were among the first delta-equipped aircraft to enter production. Whereas the Vulcan

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2860-668: Was patented 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 similarly dart-shaped proposals, such as a biplane version by Butler and Edwards, and a jet-propelled version by the Russian Nicholas de Telescheff . In 1909 a variant with a canard foreplane was experimented with by the Spanish sculptor Ricardo Causarás. Also in 1909, British aeronautical pioneer J. W. Dunne patented his tailless stable aircraft with conical wing development. The patent included

2915-439: 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 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. The American aerodynamicist Robert T. Jones , who worked at NACA during

2970-522: Was adopted by the TsAGI (Central Aero and Hydrodynamic Institute, Moscow ), to improve high angle-of-attack 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. Through the 1960s, the Swedish aircraft manufacturer Saab AB developed a close-coupled canard delta configuration, placing

3025-545: Was used both in the air-to-air role, carried by Aeritalia F-104s in the apposite versions F-104S and F-104ASA, and in the surface-to-air naval role. In the latter role it has been replaced by the MBDA Aster . Naval Aspide launchers can be adapted to fire the Sparrow by merely switching a single circuit board. In the mid 1980s, China imported a small batch of the Aspide Mk.1 from Italy, then signed an agreement with Alenia to produce

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