The SH-3 Sea King (aka S-61) is a medium lift transport and commercial airliner helicopter designed by Sikorsky Aircraft. It is manufactured by AgustaWestland in the UK and Mitsubishi in Japan. It first took flight in March of 1959 and was officially introduced in 1961.
During the time leading up to the development of the Sea King the threat of Soviet submarines was a primary concern of the US government. The US was convinced that if the Soviets were to use a nuclear weapon against them, it would almost definitely be delivered via a submarine platform.
The Sea King was thus developed after Sikorsky won a contract from the United States Navy for an amphibious transport helicopter that could also perform anti-submarine warfare duties. After WW II it was clear that using surface vessels was not an effective way to fight submarines and so the strategy of using helicopters with active-sonar dipping became the preferred deterrent. It was in fact the Sikorsky HOS (R-6) that first demonstrated the practical possibility of anti-submarine helicopters in 1946.
Sikorsky wasted no time in creating civilian variants of the Sea King, specifically the S-61L and S-61N. To this day these civilian versions are some of the most widely used helicopters in the oil industry and are just as widely used as airliners.
The military version is armed with up to four torpedoes and can also carry four depth charges. The Sea King can also carry two anti-ship missiles, including fire-and-forget models with a range of 100km.
The Sea King is powered by two Rolls-Royce Gnome H1400-1T turboshaft engines with an output of 1 238 kW each. With its six flexible fuel bags the Sea King has a range of 1 500 kilometers, which can be extended by 250 kilometers with an auxiliary tank.
Apart from its warfare role, the Sea King is also equipped for excellent search and rescue ability, with its formidable range giving it legs on the open water to comfortably reach those in need of assistance.
The Sea King Remains in service today, even after 25 years. The Royal Navy alone has 344 units active.
Production of the S-61 ended in 1980 after having served in over 30 countries across the world. Agusta has however stated that, should it be needed, they could resume production of new AS-61 units in 36 months.