Lockheed S-3 Viking - Development

Development

In the mid-1960s, the U.S. Navy developed the VSX (Heavier-than-air, Anti-submarine, Experimental) requirement for a replacement for the piston-engined Grumman S-2 Tracker as an anti-submarine aircraft to fly off the Navy's aircraft carriers. In August 1968, a team led by Lockheed and a Convair/Grumman team were asked to further develop their proposals to meet this requirement. Lockheed recognised that it had little recent experience in designing carrier based aircraft, so Ling-Temco-Vought (LTV) was brought into the team, being responsible for the folding wings and tail, the engine nacelles, and the landing gear, which was derived from A-7 Corsair II (nose) and F-8 Crusader (main). Sperry Univac Federal Systems was assigned the task of developing the aircraft's onboard computers which integrated input from sensors and sonobuoys.

On 4 August 1969, Lockheed's design was selected as the winner of the contest, and eight prototypes, designated YS-3A were ordered. The first prototype flew on 21 January 1972 and the S-3 entered service in 1974. During the production run from 1974 to 1978, a total of 186 S-3As were built. The majority of the surviving S-3As were later upgraded to the S-3B variant, with sixteen aircraft converted into ES-3A Shadow electronic intelligence (ELINT) collection aircraft.