The Sikorsky SH-3 Sea King with its many progeny and variants ranks as one of aviation history’s most successful and numerous naval helicopters. Originally designated HSS-2, the aircraft was the first antisubmarine warfare (ASW) helicopter to effectively combine search/location and attack capabilities in a single airframe.
The Sea King was developed as a successor the firm’s widely flown S-58 series, with more than 2,300 produced in the United States and England for military and civilian use. In U.S. service this helicopter flew as the H-34 Choctaw, HSS-1 Seabat, and HUS Seahorse.1 Although the Sea King was radically different in design, power plant, and capabilities from the S-58, it was initially designated HSS-2, i.e., the first ASW helicopter (HS) built by Sikorsky (S), the second model. In the 1962 redesignation action, the HSS-1 became the SH-34 and the Sea King the SH-3, the third helicopter in a new designation series.
The basic ASW model first flew on 11 March 1959. A large helicopter, the SH-3A had a combat weight of just over 18,000 pounds carrying four Mark 44 homing torpedoes. Twin turbine engines (mounted atop the fuselage) and a large fuel capacity (658 gallons) gave the Sea King both speed and range. Indeed, in 1962 an SH-3A became the first helicopter to break the 200-mph “barrier” for rotary-wing aircraft. And the Sea King established several non-refueled records on transcontinental and transatlantic flights.
The turbines turned five-blade main and tail rotors. Naval variants had folding main rotor blades and on some models the tailboom also folded for shipboard stowage. The naval helicopters had a “boat” hull, but only the Coast Guard’s HH-3F Pelican was intended for water landings. The land-based aircraft did not have watertight hulls and were fitted with a hydraulically operated rear ramp for loading cargo and troops. The naval variants had fixed landing gear; the land-based helicopters had retractable gear.
Unlike the previous HSS-1/SH-34, which could carry either sensors or torpedoes, the SH-3A was fitted with the APN-130 navigation radar and AQS-10 dipping (active) sonar. Later ASW variants, with more advanced radar and sonar, also had sonobuoys, magnetic anomaly detection, electronic surveillance measures, and chaff.
The Sea King entered U.S. Navy service in September 1961 with helicopter ASW squadrons HS-3 and HS-10 and was assigned to antisubmarine warfare carriers—CVS. With the subsequent demise of those ships, in the early 1970s they began going aboard multimission carriers (CV/CVN) in eight-helicopter squadrons, later reduced to six aircraft.
The British and Canadian navies flew the Sea King from destroyer-type ships as well as their aircraft carriers.2
U.S. Navy development of the Sea King was quickly followed by Air Force interest, with a land-based variant being developed for the cargo (CH-3) and combat search-and-rescue (HH-3E) roles. The latter, named Jolly Green Giants, were used extensively in Vietnam, as were Navy ASW and rescue-configured Sea Kings flying from surface combatants as well as aircraft carriers.
The Navy converted 12 Sea Kings to the HH-3A configuration, adding 7.62-mm miniguns, extra fuel tanks, armor, and a rescue hoist. A more specialized—but unarmed—rescue variant was the Coast Guard’s HH-3F Pelican. Rescue gear was installed with space for 15 passengers.
Navy Sea Kings were also used for another kind of rescue—spacecraft recovery. The United States opted for water recovery over ground landing of its one-man Mercury, two-man Gemini, and three-man Apollo spacecraft. While Navy UH-34s were used for the early Mercury recoveries, the SH-3 was employed for two later Mercury flights, most of the Gemini, and all of the Apollo flights.
Special-purpose Sea Kings included nine converted for mine countermeasures (RH-3A), one modified for advanced helicopters concepts by the National Aeronautics and Space Administration (NH-3A), one modified for deicing tests (JCH-3C), and two converted to test beds for the Light Airborne Multi-Purpose System (LAMPS, designated YSH-3J). The Air Force built three CH-3B versions for drone recovery; these were amphibious, similar to the SH-3 but without ASW equipment.
As early as 1962 an SH-3A assigned to the store ship Altair (AKS-32) and another on the fleet oiler Mississinewa (AO-144) carried out vertical replenishment (VERTREP) of 6th Fleet warships in the Mediterranean. In 1965 the Altair conducted what was probably the first night VERTREP of a carrier.
The VH-3A Sea King was developed specifically as a VIP transport for the U.S. president and other senior executives. The five of these built by Sikorsky had suitable accommodations, enhanced communications, and certain security features.
The original VH-3A was succeeded by the more capable and better protected VH-3D variants. The latter—known as “white tops”—remain in service today with Marine helicopter squadron HMX-1, based at Quantico, Virginia, with a forward operating base at Naval Air Station Anacostia, Washington, D.C.
The last American-built Sea King was delivered in 1975. The estimated 604 American-built Sea Kings were augmented by hundreds built under license in the United Kingdom by Westland, in Italy by Agusta, and in Japan by Mitsubishi. Total production was just over 1,000 helicopters.
After the United States, the largest user has been Britain, which used the name Commando for troop/cargo aircraft flown by the Royal Marines. And some British helicopters have been fitted with antiship missiles.
A major shortfall of the Royal Navy during the 1982 Falklands War was the lack of an airborne early-warning (AEW) capability. The Royal Air Force was supposed to provide AEW support to the Navy, but its land-based AEW aircraft could not reach the fleet’s operating areas. Existing Navy Sea Kings were upgraded to the AEW.2 configuration, being fitted with the Searchwater search radar. These have now been redesignated airborne surveillance and area control (ASaC) aircraft.
The advanced Sea King ASaC.7 variant was first deployed on board the carrier Ark Royal for Operation Iraqi Freedom in 2003. They provided tactical control for Sea Harriers and other land- and carrier-based aircraft, could detect low-flying aircraft, and could perform surface search.
The presidential VH-3D Sea Kings are the only Sea King–type helicopters now flown by the U.S. armed forces. The last Navy-flown Sea Kings left the fleet in 1996, being replaced on carriers by the SH-60F Seahawk and, subsequently, by the MH-60R and MH-60S variants.
Sea Kings are still flying in other navies, and there is no replacement in the near-term for the Marine presidential transports. Thus, these “kings” are with us well into the 21st century.
1. See N. Polmar, “A Helicopter for All Seasons,” Naval History (October 2002), pp. 12–14.
2. In place of manned helicopters, during that period the U.S. Navy employed the DSN/QH-50 unmanned drone on board surface combatants; these helicopters had no sensors, but were strictly a weapons delivery platform, carrying ASW homing torpedoes or a nuclear depth bomb.