The Sikorsky SH-3 Sea King (company designation S-61) is a twin-engined anti-submarine warfare (ASW) helicopter. It served with the United States Navy and other forces, and continues to serve in many countries around the world. The Sea King has been built under license in Italy and Japan, and in the United Kingdom as the Westland Sea King. The major civil versions are the S-61L and S-61N.
The Sea King first flew on 11 March 1959; it became operational with the United States Navy in June 1961 as the HSS-2. The designation for the aircraft was changed with the introduction of the unified aircraft designation system in 1962 to the SH-3A. It was used primarily for anti-submarine warfare, but also served in anti-ship, search and rescue, transport, communications, executive transport and Airborne Early Warning roles. Aircraft carriers always deployed the Sea King as the first aircraft in the air and the last to land serving in air operations as plane guard and SAR for the fixed winged aircraft. An SH-3A, operating from the USS New Orleans amphibious assault ship, was used in the February 1971 Apollo 14 recovery mission.
In the US Navy, it was replaced in the ASW and SAR roles by the SH-60 Sea Hawk during the 1990s, but continues in service for other roles, for ASW in the reserves, and around the world. All H-3 aircraft in US Navy service are used in the logistics support, range support, Search and Rescue, test, and VIP transport roles. The H-3 was finally retired on 27 January 2006 in a Final Flight ceremony in NAS Norfolk, Virginia, by Helicopter Combat Support Squadron 2 (HC-2), the Fleet Angels. HH-3 variants based on the SH-3 airframe were built for the US Air Force.
Sea Kings are used as one of the official helicopters of the President of the United States and are operated by the United States Marine Corps. Sea Kings use the call sign Marine One when the president is aboard.