Editing Delta wing (section)

==History==

===Early research===
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]].<ref>{{cite web | trans-title = Corad Haas rocket pioneer in Transylvania | url = http://www.sibiweb.de/vip/haas/ | title = Corad Haas Raketenpionier in Siebenbürgen | work = Beruehmte Siebenbuerger Sachsen | publisher = Siebenbürgen und die Siebenbürger Sachsen im Internet | language = de | access-date = 2010-09-09 | archive-date = 2018-09-17 | archive-url = https://web.archive.org/web/20180917161453/http://www.sibiweb.de/vip/haas/ | url-status = live }}</ref><ref>{{Citation | url = http://www.nasa.gov/pdf/153410main_Rockets_History.pdf | archive-url = https://web.archive.org/web/20100119181932/http://www.nasa.gov/pdf/153410main_Rockets_History.pdf | url-status = dead | archive-date = 2010-01-19 | title = New Rocket Guide | publisher = NASA}}.</ref><ref>{{Citation | first = Bolesław | last = Orłowski | title = Technology and Culture | volume = 14 | number = 3 |date=Jul 1973 | pages = 461–73 | publisher = JStor | doi = 10.2307/3102331 | jstor=3102331| s2cid = 113306514 }}.</ref> However, a true lifting wing in delta form did not appear until 1867, when it was [[patent]]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 similarly dart-shaped proposals, such as a biplane version by Butler and Edwards, and a jet-propelled version by the Russian [[Nicholas de Telescheff]].<ref>Wragg, David W.; ''Flight Before Flying'', Osprey, 1974, pp. 87-88, 96.</ref> In 1909 a variant with a [[canard (aeronautics)|canard foreplane]] was experimented with by the Spanish sculptor Ricardo Causarás.<ref>[http://centenariaviacio.catedradr.com/site/upload/ficheros/d-09.pdf "El Aeroplano-Monoplano Causarás en la Presna de 1909"]. ''1909-2009 100 Anos de Aviacion Espanola''. Generalitat Valencia. 2002. Retrieved 17 April 2023.</ref><ref>[http://centenariaviacio.catedradr.com/site/upload/ficheros/d-04b.pdf Patent application 46026 "Aeroplano Monoplano Causarás"]. Ricardo Causarás. 1909. Retrieved 17 April 2023.</ref>

Also 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]].<ref>J.W. Dunne; ''Provisional Patent: Improvements Relating to Aeroplanes'', UK Patent No. 8118, Date of Application 5 April 1909. [http://worldwide.espacenet.com/espacenetDocument.pdf?ND=5&flavour=trueFull&locale=en_EP&FT=D&date=19100331&CC=GB&NR=190908118A Copy on Espacenet] {{Webarchive|url=https://web.archive.org/web/20211001034352/https://worldwide.espacenet.com/publicationDetails/originalDocument?ND=5&flavour=trueFull&locale=en_EP&FT=D&date=19100331&CC=GB&NR=190908118A |date=2021-10-01 }}</ref> 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.<ref name="woodhams">Woodhams, Mark and Henderson, Graeme; "Did we really fly Rogallo wings?", ''Skywings'', June 2010.</ref><ref>Lee, U. G. and Darrah, H.; US patent 989,7896, filed 15 February 1910, granted 18 April 1911.</ref> 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.<ref name="woodhams"/>

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.<ref name= secret>{{cite book | last = Ford| first= Roger| title= Germany's secret weapons in World War II| year= 2000| publisher= MBI Publishing | location = Osceola, WI | isbn=0-7603-0847-0|url=https://archive.org/details/germanyssecretwe0000ford | url-access = registration| quote = Lippisch.| edition =1st |page=[https://archive.org/details/germanyssecretwe0000ford/page/36 36]}}</ref><ref name=pop1931>{{Citation | url = https://books.google.com/books?id=ESgDAAAAMBAJ&pg=PA65 | title = New Triangle Plane Is Tailless | date = December 1931 | newspaper = Popular Science | page = 65 | access-date = 2016-10-10 | archive-date = 2014-06-27 | archive-url = https://web.archive.org/web/20140627194855/http://books.google.com/books?id=ESgDAAAAMBAJ&pg=PA65 | url-status = live }}.</ref> These prototypes were not easy to handle at low speed and none saw widespread use.<ref>{{cite book | last1 = Madelung | first1 = Ernst Heinrich | last2 = Hirschel | first2 = Horst | last3 = Prem | first3 = Gero | title = Aeronautical research in Germany: from Lilienthal until today | year = 2004 | publisher = Springer | location = Berlin | isbn = 3-540-40645-X | url = https://books.google.com/books?id=OoFcHOLpCskC&q=Lippisch%20Horten&pg=PA168 | edition = American | access-date = 2020-10-04 | archive-date = 2021-10-01 | archive-url = https://web.archive.org/web/20211001034351/https://books.google.com/books?id=OoFcHOLpCskC&q=Lippisch+Horten&lpg=PA168 | url-status = live }}</ref><ref>{{cite book |last1 = Wohlfahrt |first1 = Karl |last2 = Nickel |first2 = Michael |title = Schwanzlose flugzeuge : ihre auslegung und ihre eigenschaften |year = 1990 |publisher = Birkhauser |trans-title = Tailless aircraft: their design & properties |location = Basel |isbn = 3-7643-2502-X |url = https://books.google.com/books?id=33fBLs7FhQ8C&q=Lippisch%20Horten&pg=PA577 |access-date = 13 February 2011 |pages = 577–78 |language = de |quote = [Lippisch Delta I and Horten H I] Both these aircraft shown, how not to do it. |archive-date = 1 October 2021 |archive-url = https://web.archive.org/web/20211001034351/https://books.google.com/books?id=33fBLs7FhQ8C&q=Lippisch+Horten&lpg=PA577 |url-status = live }}</ref>

===Subsonic thick wing===
[[File:Vulcan.delta.arp.jpg|thumb|right|The [[Avro Vulcan]] bomber had a thick wing]]
During the latter years of [[World War II]], Alexander Lippisch refined his ideas on the high-speed delta, substantially increasing the sweepback of the wing's leading edge. An experimental glider, the [[Lippisch DM-1|DM-1]], was built to test the aerodynamics of the proposed [[Lippisch P.13a|P.13a]] high-speed [[interceptor aircraft|interceptor]].<ref>{{Citation | publisher = Youtube | url = https://www.youtube.com/watch?v=MvtxjSrImHw | last = Grommo | date = 17 May 2008 | title = Lippisch P13a Supersonic Ramjet Fighter footage | format = video | access-date = 27 November 2016 | archive-date = 15 April 2016 | archive-url = https://web.archive.org/web/20160415131015/https://www.youtube.com/watch?v=mvtxjsrimhw | url-status = live }}.</ref> 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 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]].<ref>[http://apps.dtic.mil/dtic/tr/fulltext/u2/a801410.pdf "Research Memorandum L7F16"] {{Webarchive|url=https://web.archive.org/web/20170503011249/http://www.dtic.mil/dtic/tr/fulltext/u2/a801410.pdf |date=2017-05-03 }}, NACA, 5 August 1947.</ref>

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 the Second World War brought a halt to flight testing of the [[Payen PA-22|Pa-22]], although work continued for a time after the project garnered German attention.<ref name="Lepage">{{cite book |last=LePage |first=Jean-Denis G. G. |title=Aircraft of the Luftwaffe, 1935-1945: an illustrated guide |year=2009 |publisher=McFarland |page=243 |isbn=978-0-7864-3937-9}}</ref> During the [[postwar]] era, Payen flew an experimental tailless delta jet, the [[Payen Pa.49|Pa.49]], in 1954, as well as the tailless pusher-configuration [[Payen Arbalète|Arbalète]] series from 1965. Further derivatives based on Payen's work were proposed but ultimately went undeveloped.<ref name="JAWA72">{{cite book |title= Jane's All the World's Aircraft 1972–73 |last= Taylor |first= John W. R. |year=1972 |publisher= Sampson Low, Marston & Co. Ltd |location= London |pages=71–2}}</ref><ref name=JAWA73>{{cite book |title= Jane's All the World's Aircraft 1973-74 |last= Taylor |first= John W. R. |year=1973|publisher=Jane's Yearbooks |location= London |isbn=0-354-00117-5 |pages=75–6}}</ref>

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.<ref>Hygate, Barrie; ''British Experimental Jet Aircraft'', Argus, 1990.</ref> 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 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.<ref>{{Citation | last = Partridge | first = J | title = Number 179 – The Gloster Javelin 1-6 | publisher = Profile | year = 1967}}.</ref> 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.<ref>Buttler, 2017, pp. 94, 98-100.</ref>

===Supersonic thin wing===
[[File:SSSR-MiG-21SM(DN-ST-82-10891).jpg|thumb| The [[MiG-21]] fighter had a conventional tail]]
The American aerodynamicist [[Robert Thomas Jones (engineer)|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]] in 1948, making it the first delta-winged jet plane to fly.<ref>Jones, Lloyd, S.; ''U.S. Fighters'', Aero, 1975. p.247.</ref> It provided a successful basis for all practical supersonic deltas and the configuration became widely adopted.<ref>Von Karman, "Aerodynamics: Selected Topics in the Light of their Historical Development." 1954.</ref><ref>Hallion, Richard. "Lippisch, Gluhareff and Jones: The Emergence of the Delta Planform." ''Aerospace Historian'', March 1979.</ref>

During the late 1940s, the British aircraft manufacturer [[Fairey Aviation]] became interested in the delta wing,<ref name = "wood 73">Wood 1975, p. 73.</ref> its proposals led to the experimental [[Fairey Delta 1]] being produced to [[List of Air Ministry specifications|Air Ministry Specification E.10/47]].<ref name = "wood 74">Wood 1975, p. 74.</ref> A subsequent experimental aircraft, the [[Fairey Delta 2]] set a new [[Flight airspeed record|World air speed record]] on 10 March 1956, achieving 1,132&nbsp;mph (1,811&nbsp;km/h) or Mach 1.73.<ref name = "WG777 ind his">[http://www.rafmuseum.org.uk/documents/collections/85-A-10-Fairey-FD-2-WG777.pdf "Individual History: Fairey FD-2 Delta WG777/7986M."] {{Webarchive|url=https://web.archive.org/web/20200626142604/http://www.rafmuseum.org.uk/documents/collections/85-A-10-Fairey-FD-2-WG777.pdf |date=2020-06-26 }} ''Royal Air Force Museum'', Retrieved: 13 December 2016.</ref><ref name = "50 years flight">[https://www.flightglobal.com/news/articles/50-years-ago-16-mar-1956-205374/ "50 years ago: 16 Mar 1956."] {{Webarchive|url=https://web.archive.org/web/20161220154526/https://www.flightglobal.com/news/articles/50-years-ago-16-mar-1956-205374/ |date=20 December 2016 }} ''Flight International'', 10 March 2006.</ref><ref name = "wood 77">Wood 1975, p. 77.</ref><ref name = "rafmus over">[http://www.rafmuseum.org.uk/research/collections/fairey-fd2/ "Fairey FD2."] {{Webarchive|url=https://web.archive.org/web/20200628012952/http://www.rafmuseum.org.uk/research/collections/fairey-fd2/ |date=2020-06-28 }} ''Royal Air Force Museum'', Retrieved: 13 December 2016.</ref> This raised the record above 1,000&nbsp;mph for the first time and broke the previous record by 310&nbsp;mph, or 37 per cent; never before had the record been raised by such a large margin.<ref name = "50 years flight"/><ref name = "wood 79">Wood 1975, p. 79.</ref>

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 the first operational jet fighters to feature a tailless delta wing when they entered service in 1956.<ref>{{citation |title=Early Supersonic Fighters of the West |last= Gunston |first=Bill |year= 1976 |publisher= Ian Allan Ltd. |location=Shepperton |isbn=0-7110-0636-9 |id= 103/74 |pages=181 and 230}}</ref> Dassault's interest in the delta wing produced the [[Dassault Mirage]] family of combat aircraft, especially the highly successful [[Dassault Mirage III|Mirage III]]. Amongst other attributes, the Mirage III was the first Western European combat aircraft to exceed Mach 2 in horizontal flight.<ref name="Mirage III">[https://web.archive.org/web/20151218081714/http://www.dassault-aviation.com/fr/passion/avions/dassault-militaires/mirage-iii/?xtmc=mirage-iii&xtrc=0%20Mirage%20III "Mirage III."] ''Dassault Aviation'', 18 December 2015.</ref>

The tailed delta configuration 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 resulting TsAGI S-12 airfoil was used in the [[Mikoyan-Gurevich MiG-21]] ("Fishbed"), which became the most widely built combat aircraft of the 1970s.<ref>Sweetman, Bill & Gunston, Bill; ''Soviet Air Power: An Illustrated Encyclopedia.'' Salamander, 1978, p. 122.</ref>

===Close-coupled canard===
[[File:Saab viggen underside.jpg|thumb|The [[Saab Viggen]] pioneered the close-coupled canard]]
{{main article|Canard (aeronautics)}}
Through the 1960s, the [[Sweden|Swedish]] 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.<ref>{{Citation | last1 = Green | first1 = W | last2 = Swanborough | first2 = G | title = The complete book of fighters | publisher = Salamander | year = 1994 | pages=514 to 516}}.</ref> [[Patent]]ed in 1963, this configuration was flown for the first time on the company's [[Saab 37 Viggen|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 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.<ref name="saab 60" >[http://saabgroup.com/about-company/history/1960s/ "1960s."] {{Webarchive|url=https://web.archive.org/web/20200629225459/https://saabgroup.com/about-company/history/1960s/ |date=2020-06-29 }} ''Company History'', Saab. Retrieved 6 March 2016.</ref><ref name="bomber 244">Gunston and Gilchrist 1993, p. 244.</ref>

The close-coupled canard has since become common on supersonic fighter aircraft. Notable examples include 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.<ref name="warwick 1260" >Warwick 1980, p. 1260.</ref><ref>Roskam 2002, p. 206.</ref>

===Supersonic transport===
{{main article|Supersonic transport}}
When supersonic transport (SST) aircraft were developed, the tailless ogival delta wing was chosen for both the Anglo-French [[Concorde]] and the Soviet [[Tupolev Tu-144]], the Concorde beginning test flights in 1965 and 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.<ref name=gordon>Tupolev Tu-144, Gordon, Komissarov and Rigmant 2015, Schiffer Publishing Ltd, {{ISBN|978-0-7643-4894-5}}</ref> 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.{{sfn|Orlebar|2004|p=44}} Its typical landing speed was {{convert|170|mph|km/h|0}}, considerably higher than subsonic airliners.{{sfn|Schrader|1989|p=84}} 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.<ref name="Independent">{{Citation | url = https://www.independent.co.uk/travel/news-and-advice/concordes-successor-revealed-at-paris-air-show-2300191.html | title = Concorde's successor revealed at Paris Air Show | newspaper = [[The Independent]] | date = 20 June 2011 | access-date = 21 June 2011 | archive-date = 22 June 2011 | archive-url = https://web.archive.org/web/20110622035456/http://www.independent.co.uk/travel/news-and-advice/concordes-successor-revealed-at-paris-air-show-2300191.html | url-status = live }}</ref>

===Rogallo flexible wing===
[[File:Birdman MJ-5 0002.jpeg|thumb|This hang glider is a relatively broad-span and lightly swept Rogallo delta]]
{{Main|Rogallo wing}}
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 [[Ryan XV-8|XV-8]], an experimental "flying Jeep" or "fleep". The flexible wing chosen for it was a delta wing; 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 gliders]] and [[ultra-light aircraft]] and has become known as the Rogallo wing.