Editing Variable-sweep wing (section)

===Development===
[[File:Tornado variable sweep wing Manching.JPG|thumb|right|Wing pivot mechanism of a [[Panavia Tornado]] during overhaul]]
[[File:Aircraft_engine_MiG-23_sweep_wing_mechanism.jpg|thumb|right |[[MIG-23]] sweep wing mechanism]]
Following the end of the conflict, the partially complete P.1101 was recovered and transported to the [[United States]], where it was studied in depth by [[Bell Aircraft]]. However, due to a lack of documentation as well as some structural damage sustained,<ref name= Myrha>{{cite book |last1=Myrha |first1=David |title=The Messerschmitt Me P.1101 |date=1999 |publisher=Schiffer Pub. Ltd |location=Atglen, PA |isbn=0-7643-0908-0}} {{Page needed|date=September 2010}}</ref><ref name="Ford 224"/> Bell decided against completing the aircraft itself. Instead, a close copy, known as the [[Bell X-5]], was constructed with wings that enabled the sweep angle to be altered mid-flight. As the wing swept back, the root also slid forwards, maintaining the centre of lift in a constant position.<ref>Abzug and Larrabee, Airplane Stability and Control: Second Edition. {{ISBN|978-0-521-02128-9}}. p. 244.</ref> A variable-sweep wing of this sliding type was flown on the prototype [[Grumman XF10F Jaguar]] in 1952. However, flight testing of the F10F proved to be unacceptable, albeit for other factors such as a lack of engine power and considerable controllability issues.<ref name="Winchester p. 295">Winchester 2005, p. 295.</ref><ref name="DeMeis p. 32">DeMeis 1976, p. 32.</ref>

During the late 1940s, British engineer [[L. E. Baynes]] started studying the variable sweep wing. He devised a method of varying the tail geometry as well in order to stabilise the centre of lift; no sliding mechanism was necessary, instead, the wing wake interacted with the variable tail to effect the necessary trim changes. During 1949 and 1951, Baynes filed [[patent]] applications associated with this work.<ref>[https://worldwide.espacenet.com/patent/search/family/009820842/publication/GB664058A UK Patent GB664058A], Espacenet</ref><ref>[https://worldwide.espacenet.com/patent/search/family/009757755/publication/GB713525A UK Patent GB713525A], Espacenet</ref> While the design reached the physical modelling stage and was subject to a complete round of wind tunnel tests, the British Government failed to provide financial backing for the work, allegedly due to [[1957 Defence White Paper|budget constraints at the time]].{{citation needed|date=March 2020|reason=testing and cancellation unsourced}}

Independently from Baynes, British engineer Barnes Wallis was also developing a more radical variable-geometry concept, which he called the wing controlled aerodyne, to maximise the economy of high-speed flight. His first study was the Wild Goose project.<ref name=BW>{{Cite web |url=http://www.sirbarneswallis.com/Supersonics.htm |title=Barnes Wallis Supersonics, ''Wild Goose'' |access-date=23 September 2018 |archive-url=https://web.archive.org/web/20181010030449/http://www.sirbarneswallis.com/Supersonics.htm |archive-date=10 October 2018 |url-status=live |df=dmy-all }}</ref> Subsequently, Barnes devised the [[Vickers Swallow|Swallow]],<ref name=BW/> a [[Blended Wing Body|blended wing]] tailless aircraft, which was envisioned to be capable of making return flights between Europe and [[Australia]] within ten hours. Later on, the Swallow was increasingly viewed as a potential supersonic successor to the subsonic [[Vickers Valiant]], one of the RAF's [[V bomber]]s.<ref name = "wood 189 191"/> During the 1950s, several modes of the Swallow were subjected to promising tests, including a six-foot [[scale model]], at speeds of up to Mach 2. However, in 1957, British government decided to withdraw backing from many aeronautical programs, including Wallis' work.<ref>[http://www.barneswallistrust.org/swingwing.htm "Swing Wing."] {{Webarchive|url=https://web.archive.org/web/20070406082053/http://www.barneswallistrust.org/swingwing.htm |date=6 April 2007 }} ''The Barnes Wallis Memorial Trust.'' Retrieved: 14 May 2013.</ref><ref name = "wood 189 191">Wood 1975, pp. 189-191.</ref>

Despite this lack of backing, the Swallow attracted international attention for some time. During late 1958, research efforts were temporarily revived through cooperation with the [[Mutual Weapons Development Programme]] of [[NATO]], under which all of Wallis' variable geometry research was shared with the Americans.<ref name="wood 189 191" /> According to aviation author James R. Hansen, American aerospace engineer [[John Stack (engineer)|John Stack]] was enthusiastic on the concept, as were numerous engineers at [[NASA]]; however, the [[United States Department of Defense]] was opposed to committing any resources to the project.<ref>Hansen 2004, pp. 129-130.</ref> Wallis collaborated with NASA's Langley Laboratory on a design study for a variable-sweep fighter. Although it used the pivot mechanism he had developed, NASA also insisted on implementing a conventional horizontal stabiliser to ease the issues of trim and manoeuvrability. Although it was no longer the wing-controlled aerodyne that Wallis envisaged, it would prove a more practical solution than either his or Bell's. Swallow research led to several new configurations, including the adoption of a compact folding tail section and [[Canard (aeronautics)|canard]]s.<ref>Hansen 2004, pp. 130-132.</ref>

Barnes' work inspired a number of further studies, including a wing controlled aerodyne in response to OR.346 for a supersonic STOL fighter-bomber, then as BAC two further submissions: the Type 583 to meet Naval ER.206 and Type 584 to meet NATO NBMR.3, both also being V/STOL requirements.<ref name="wood"/> In 1960, [[Maurice Brennan]] joined [[Folland Aircraft]] as its chief engineer and director; he soon set about harnessing his experience of variable-geometry wings.<ref name = "wood 197">Wood 1975, p. 197.</ref> Accordingly, such a wing was combined with the firm's [[Folland Gnat]] light fighter for two different concepts – one tailless and one using with a conventional tail – for a multipurpose fighter/strike/trainer, designated as the Fo. 147. It had a unique mechanism for wing sweep that combined tracks on the fuselage sides and the underside of the wings, which was actuated by [[hydraulics|hydraulically]]-driven [[ball screw]]s positioned at the wing's inner ends.<ref name = "wood 198">Wood 1975, pp. 198.</ref> The wings could be swept from 20 degrees to 70 degrees; at the 70-degree position, [[Flight control surfaces#Longitudinal axis|longitudinal control]] was maintained by wing tip-mounted [[elevon]]s, while this was provided by a retractable canard arrangement when swept at the 20-degree position, using full auto-[[Stabilizer (aeronautics)|stabilisation]]. By providing [[Trim tab|trimming]] functionality via the canard, the necessity of a large tailplane was eliminated.<ref name = "wood 198 199">Wood 1975, pp. 198–199.</ref> The Fo. 147 was claimed to have been capable of speeds in excess of Mach 2, being limited only by the heat buildup generated by high speed flight.<ref name = "wood 199">Wood 1975, p. 199.</ref> Ultimately, the concept would not be developed to the prototype stage while the RAF showed little interest in the prospective variable geometry trainer.<ref name = "wood 199"/>