Editing Lockheed S-3 Viking (section)

==Development==
[[File:YS-3A Viking prototype.jpg|alt=|thumb|YS-3A prototype]]
[[File:S-3A escape sys China Lake NAN1-72jpg.jpg|thumb|S-3 escape system testing]]

In the mid-1960s, the [[United States Navy]] (USN) formulated the ''VSX'' (Heavier-than-air, Anti-submarine, Experimental) requirement, which sought a dedicated anti-submarine aircraft capable of flying off of its aircraft carriers as a replacement for its existing inventory of piston-engined [[Grumman S-2 Tracker]]s. The service issued a request for proposals to industry. During August 1968, a team led by Lockheed, as well as a rival team comprising [[Convair]] and [[Grumman]], were requested to further develop their proposals to meet this requirement.<ref name="Frnc Lock p455-6">Francillon 1982, pp. 455–456.</ref>

At this stage, Lockheed recognised that it had little experience in designing carrier based aircraft, thus the company reached out to the industrial conglomerate [[Vought|Ling-Temco-Vought]] (LTV), which joined the team. LTV assumed responsibility for the design of various elements of the airframe, such as the folding wings and tail, the engine nacelles, and the landing gear, some of which had been derived from the earlier [[LTV A-7 Corsair II]] and [[Vought F-8 Crusader]]. [[UNIVAC|Sperry Univac]] Federal Systems was assigned the task of developing the aircraft's onboard computers which integrated input from sensors and [[sonobuoy]]s.<ref name="Fixer p6">Godfrey 1974, p. 6.</ref><ref name="gvg">Goebel, Greg. {{usurped|1=[https://web.archive.org/web/20041231024042/http://www.vectorsite.net/avs3.html "The Lockheed S-3 Viking."]}} ''Air Vectors'', 1 May 2005. Retrieved: 21 April 2010.</ref>

On 4 August 1969, Lockheed's design was selected as the winner of the VSX contest; an order for eight prototypes, designated ''YS-3A'', was promptly received by the company.<ref name="Frnc Lock p457">Francillon 1982, p. 457.</ref><ref name = "desertwarrior 2009"/> On 21 January 1972, the first prototype performed its [[maiden flight]] in the hands of military test pilot [[John Christiansen]].<ref>Francillon 1987, p. 467.</ref><ref name="Fixer p6"/> Flight testing proceeded quickly with no major issues; two years later, the S-3 entered operational service with the U.S. Navy. During the type's production run, which ran from 1974 to 1978, a total of 186 S-3As were constructed.<ref name = "desertwarrior 2009"/> The majority of the surviving S-3As were later upgraded to the improved ''S-3B'' variant, while 16 aircraft were also converted into ''ES-3A Shadow'' [[electronic intelligence]] (ELINT) collection aircraft.