in 1975 On 20 February 1974, the S-3A officially became operational with the
Air Antisubmarine Squadron FORTY-ONE (VS-41), the "Shamrocks," at
NAS North Island, California, which served as the initial S-3 Fleet Replacement Squadron (FRS) for both the Atlantic and Pacific Fleets until a separate Atlantic Fleet FRS, VS-27, was established in the 1980s. The first operational cruise of the S-3A took place in 1975 with the
VS-21 "Fighting Redtails" aboard . Starting in 1987, the majority of S-3As were progressively upgraded to the improved
S-3B standard; this involved the addition of several new sensors, avionics, and weapons systems, which included the capability to launch the
AGM-84 Harpoon anti-ship missile. As a consequence of the collapse of the
Soviet Union and the breakup of the
Warsaw Pact in the early 1990s, the Soviet-Russian submarine threat was perceived as much reduced, and the Vikings had the majority of their
antisubmarine warfare equipment removed. The aircraft's mission subsequently changed to sea surface search, sea and ground attack, over-the-horizon targeting, and aircraft refueling. It was commonly deployed to hunt for
Scud missile launcher. The Vikings also identified and targeted numerous Iraqi naval vessels, and even destroyed anti-aircraft gun emplacements and coastal radars.
Final years and retirement 's S-3B, callsign "Bloodhound 700", in 2010. from 2009 to 2021. A proposed airframe known as the
Common Support Aircraft was advanced as a successor to the S-3,
E-2, and
C-2, but this initiative failed to materialize. In 1998, the U.S. Navy awarded a $40 million contract for Lockheed Martin to perform a full-scale
Fatigue testing of the existing S-3s; these tests, which commenced in June 2001, were aimed at extending the viable service life of each remaining aircraft, which had originally been certified for a structural life of 13,000 flight-hours. It was hoped that this could be extended to as much as 17,750 hours. The final carrier-based S-3B squadron, VS-22, was decommissioned at NAS Jacksonville on 29 January 2009. Sea Control Wing Atlantic was decommissioned the following day, along with the last S-3s in frontline fleet service. These S-3Bs are flown by Air Test and Evaluation Squadron Thirty (
VX-30) based out of
NAS Point Mugu, California. By late 2015, the U.S. Navy were operating a total of three Vikings in support roles. One was relocated to
The Boneyard in November 2015, while the final two were retired, one being stored and the other transferred to
NASA, on 11 January 2016, officially retiring the S-3 from Navy service. During 2004, NASA acquired four of the withdrawn S-3Bs for use at its
Glenn Research Center. In 2009, one of these aircraft (USN BuNo 160607) was given the civil registration
N601NA, it was involved in numerous tests conducted by the agency. For over a decade, this aircraft was flying almost every day in support for various research programs; However, a lack of spare parts and increasing difficulty supporting the type meant their use could not continue in the long term. The last of the NASA's S-3Bs, which were the final working members of the type in existence with any operator at that point, were retired on 13 July 2021.
Potential revival and proposals In October 2013, the
Republic of Korea Navy expressed its interest in acquiring up to 18 ex-USN S-3s to augment their fleet of 16 Lockheed P-3 Orion aircraft. In August 2015, a military program review group approved a proposal to incorporate 12 mothballed S-3s to perform ASW duties; the Viking plan was sent onto the
Defense Acquisition Program Administration for further assessment before final approval decision by the national defense system committee. Although the planes are relatively old, being in storage has supposedly kept them serviceable, and using them is an affordable means of fulfilling short-range airborne ASW capabilities that were vacated by the retirement of the S-2 Tracker. Refurbished S-3s could have been returned to use by 2019. During April 2014, Lockheed Martin announced that they would offer refurbished and remanufactured S-3s, dubbed the
C-3, as a replacement for the Northrop
Grumman C-2A Greyhound for
carrier onboard delivery. The requirement for 35 aircraft would be met from the 91 S-3s currently in storage. In February 2015, the Navy announced that the
Bell Boeing V-22 Osprey had been selected to replace the C-2 for the COD mission. A SV-22 was a proposed
anti-submarine warfare variant the U.S. Navy studied in the 1980s to replace S-3 Viking and late model
SH-2 Seasprite ASW helicopters. ==Variants==