Editing Saab 37 Viggen (section)

=== Origins ===
The Viggen was initially developed as an intended replacement for the [[Saab 32 Lansen]] in the attack role and later the [[Saab 35 Draken]] as a fighter.<ref name= "Karling">{{Citation |last= Karling |first= Krister |language= sv |title= Saab 37 Viggen – utvecklingen av ett Nytt Enhetsflygplan för det Svenska Flygvapnet 1952–1971: Sett ur en Aerodynamikers Perspektiv |isbn= 91-631-2395-9 |place= Stockholm |publisher= Svenska mekanisters riksfören |series= Småskrift | issn = 1652-3563 | number = 2 |trans-title= Saab 37 Viggen – Development of a New Unitary aircraft for the Swedish Air Force 1952–1971: From an Aerodynamicist's View |year= 2002}}</ref><ref name= "saab 60" /> In 1955, as Saab's prototype Draken, the most aerodynamically advanced fighter in the world at that point, performed its first flight, the Swedish Air Force was already forming a series of requirements for the next generation of combat aircraft; due to the challenging nature of these requirements, a lengthy development time was anticipated, with the first flight intended to be no earlier than the middle of the next decade.<ref name= "bomber 243">Gunston and Gilchrist 1993, p. 243.</ref><ref name= "field 707">Field 1974, p. 707.</ref> Between 1952 and 1957, the first studies towards what would become the Viggen were carried out, involving the Finnish aircraft designer [[Aarne Lakomaa]]. Over 100 different concepts were examined in these studies, involving both single- and twin engine configurations, both traditional and [[Delta wing#double delta|double delta]] wings, and [[Canard (aeronautics)|canard wings]]. Even [[VTOL]] designs were considered, with separate lift engines, but were soon identified as being unacceptable.<ref name= "Karling" /><ref name= "field 707" /><ref name= "warwick 1260" />

From the onset, the Viggen was planned as an integrated weapon system, to be operated in conjunction with the newest revision of Sweden's national electronic air defense system, [[STRIL]]-60. It was used as the nation's standard platform, capable of being efficiently adapted to perform all tactical mission roles.<ref name= "bomber 243" /> Other requirements included [[Supersonic speed|supersonic]] ability at low level, [[Mach number|Mach]] 2 performance at altitude, and the ability to make short landings at low angles of attack (to avoid damaging improvised runways). The aircraft was also designed from the beginning to be easy to repair and service, even for personnel without much training.<ref>{{Citation | first1 = Anders | last1 = Nowotny | first2 = Sten | last2 = Ekedahl | url = http://www.aircraftresourcecenter.com/AWA1/101-200/walk200_viggen/walk200.htm | title = Viggen walkaround | publisher = Aircraft resource center | access-date = 23 April 2007 | archive-date = 20 February 2007 | archive-url = https://web.archive.org/web/20070220110308/http://www.aircraftresourcecenter.com/AWA1/101-200/walk200_viggen/walk200.htm | url-status = dead }}</ref><ref>Bitzinger 1991, p. 18.</ref>

One radical requirement of the proposed aircraft was the ability for it to be operated from relatively short runways only 500 meters long; this was part of the [[Bas 60]] air base system that had been introduced by the Swedish Air Force in the late 1950s. Bas 60 revolved around [[force dispersal]] of aircraft across many wartime air bases, including [[Highway strip|road runways]] acting as backup runways.<ref>{{Cite web | place = NU |url= http://www.fht.nu/Dokument/Flygvapnet/flyg_publ_dok_flygbassystemet_bas_60.pdf |archive-url=https://web.archive.org/web/20150924012245/http://www.fht.nu/Dokument/Flygvapnet/flyg_publ_dok_flygbassystemet_bas_60.pdf |archive-date=2015-09-24 |url-status=live|title= Flygbassystem 60 |last= Rystedt|first= Jörgen |date= 1 October 2005 | work = FHT}}</ref><ref>{{Cite web | place = [[Sweden|SE]] |url= https://www.forsvarsmakten.se/siteassets/5-information-och-fakta/historia/vagbaserna/fortv-2007-1.pdf |archive-url=https://web.archive.org/web/20170603214913/http://www.forsvarsmakten.se/siteassets/5-information-och-fakta/historia/vagbaserna/fortv-2007-1.pdf |archive-date=2017-06-03 |url-status=live |title= Svenska militära flygbaser|last=Törnell |first= Bernt |date= 5 February 2007 | work = Forsvarsmakten}}</ref><ref>{{Cite web | place = SE |url= https://www.forsvarsmakten.se/siteassets/5-information-och-fakta/historia/vagbaserna/fortv_rapport_2006.1.pdf |archive-url=https://web.archive.org/web/20170604001219/http://www.forsvarsmakten.se/siteassets/5-information-och-fakta/historia/vagbaserna/fortv_rapport_2006.1.pdf |archive-date= 2017-06-04 |url-status=live |title= Svenska reservvägbaser|last= Andersson |first= Lennart |date= 23 November 2006 | work = Forsvarsmakten}}</ref> Utilizing partially destroyed runways was another factor that motivated STOL capability. Bas 60 was developed into [[Bas 90]] in the 1970s and 1980s, and included short runways only 800 meters in length.<ref>{{Cite web | place = NU |url= http://www.fht.nu/Dokument/Flygvapnet/flyg_publ_dok_flygbassystem_90.pdf |archive-url=https://web.archive.org/web/20160514115339/http://fht.nu/Dokument/Flygvapnet/flyg_publ_dok_flygbassystem_90.pdf |archive-date=2016-05-14 |url-status=live |title= Flygbassystem 90 |last= Rystedt | first= Jörgen |date= 20 April 2009 | work = FHT}}</ref> Enabling such operations imposed several critical demands upon the design, including a modest landing speed, no-flare touchdown, powerful post-landing deceleration, accurate steering even in crosswinds on icy surfaces, and high acceleration on take-off.<ref name= "bomber 243" />

In 1960, the U.S. [[United States National Security Council|National Security Council]], led by President [[Dwight D. Eisenhower|Eisenhower]], formulated a security guarantee for Sweden, promising U.S. military help in the event of a Soviet attack against Sweden; both countries signed a military-technology agreement. In what was known as the "[[Sweden–United States relations#Military relations|37-annex]]", Sweden was allowed access to advanced U.S. [[Aeronautics|aeronautical]] technology that made it possible to design and produce the Viggen much faster and more cheaply than would otherwise have been possible.<ref name= "SDRA">{{Citation |language= sv | place = SE |url= http://www.foi.se/Global/Våra%20tjänster/Rapporter/Tidningen%20Framsyn/Framsyn%202005/Framsyn%20Nr%201%202005.pdf |title= Hemliga atomubåtar gav Sverige säkerhetsgaranti |trans-title= Secret nuclear submarines gave Sweden security guarantee |newspaper= Framsyn |year= 2005 |number= 1 |publisher= The Swedish Defence Research Agency}} {{Dead link |date= March 2018 |bot= InternetArchiveBot |fix-attempted= yes}}</ref> According to research by [[Nils Bruzelius]] at the [[Swedish Defence University|Swedish National Defence College]], the reason for this officially unexplained U.S. support was to protect U.S. [[UGM-27 Polaris|Polaris]] submarines deployed just outside the Swedish east coast against the threat of Soviet anti-submarine aircraft.<ref name= "SDRA" /> However, Bruzelius' theory has been discredited by Simon Moores and Jerker Widén.<ref name="KKrVAHT nr 4 2007">{{Citation |language= sv |url= http://www.kkrva.se/wp-content/uploads/Artiklar/074/kkrvaht_4_2007_9.pdf |archive-url=https://web.archive.org/web/20120321195606/http://www.kkrva.se/wp-content/uploads/Artiklar/074/kkrvaht_4_2007_9.pdf |archive-date=2012-03-21 |url-status=live |title= En djärv tes utan empiriskt stöd |trans-title= A bold claim without empirical support |journal= KKrVAHT |number= 4 |year= 2007 |place= SE}}</ref> The connection also appears doubtful due to the time scale – the Viggen's strike version only became operational in 1971, and the fighter version in 1978, by which time Polaris had already been retired.{{Citation needed |date= March 2016}}