Lockheed S-3 Viking

The Lockheed S-3 Viking is a four-crew, twin-engine turbofan-powered subsonic anti-submarine jet aircraft designed and produced by Lockheed Corporation, nicknamed the War Hoover for its characteristic sound. It answered the US Navy VSX requirement for a successor to the piston-engined Grumman S-2 Tracker, with Ling-Temco-Vought designing parts of the airframe such as the folding wings and tail, and Lockheed's design won on 4 August 1969. The prototype YS-3A made its maiden flight on 21 January 1972 and the type entered service in February 1974. From 1974 to 1978 186 S-3As were built, most later upgraded to the S-3B, and 16 were converted to ES-3A Shadow electronic intelligence aircraft. It flew in the Gulf War, the Yugoslav Wars and the war in Afghanistan, left front-line fleet service in January 2009, and the last Navy examples retired in early 2016. NASA retired the last operational S-3 in mid-2021.