The Sikorsky SH-3 Sea King (company designation S-61) is an American twin-engined anti-submarine warfare (ASW) helicopter designed and built by Sikorsky Aircraft. A landmark design, it was one of the first ASW rotorcraft to use turboshaft engines.

The Sea King has its origins in efforts by the United States Navy to counter the growing threat of Soviet submarines during the 1950s. Accordingly, the helicopter was specifically developed to deliver a capable ASW platform; in particular, it combined the roles of hunter and killer, which had previously been carried out by two separate helicopters. The Sea King was initially designated HSS-2, which was intended to imply a level of commonality to the earlier HSS-1; it was subsequently redesignated as the SH-3A during the early 1960s.

Introduced to service in 1961, it was operated by the United States Navy as a key ASW and utility asset for several decades prior to being replaced by the non-amphibious Sikorsky SH-60 Seahawk in the 1990s. In late 1961 and early 1962, a modified U.S. Navy HSS-2 Sea King was used to break the FAI 3 km, 100 km, 500 km, and 1000 km helicopter speed records. The Sea King also performed various other roles and missions such as search-and-rescue, transport, anti-shipping, medevac, plane guard, and airborne early warning operations.

The Sea King has also proved to be popular on the export market with foreign military customers, and has also been sold to civil operators as well. As of 2024, many examples of the type remain in service in nations around the world, although some major users have begun to retire the type. The Sea King has been built under license by Agusta in Italy, Mitsubishi in Japan, Canada by United Aircraft of Canada, and by Westland in the United Kingdom as the Westland Sea King. The major civil versions are the S-61L and S-61N. The S-61R was another important variant, which was the CH-3C/E Sea King, used by the U.S. Coast Guard as the HH-3F Pelican, and the Air Force's HH-3E Jolly Green Giant; this version had a ramp at the rear among other changes.

??General characteristics??

Crew: 2 flight crew + 2 sonar operators
Capacity: (S-61A transport) 26 troops, or 15 stretchers, or 12 VIP passengers
Length: 54 ft 9 in (16.69 m)
Width: 16 ft 4 in (4.98 m) (rotors folded)
Height: 16 ft 10 in (5.13 m)
Empty weight: 11,865 lb (5,382 kg)
Gross weight: 18,626 lb (8,449 kg) (ASW mission)
Max takeoff weight: 21,500 lb (9,752 kg)
Powerplant: 2 × General Electric T58-GE-10 turboshaft engines, 1,400 shp (1,044 kW) each (total power limited to 2,500 hp (1,864 kW) by main gearbox)[107]
Main rotor diameter: 62 ft 0 in (18.90 m)
Main rotor area: 3,019 sq ft (280.5 m2)
Blade section: NACA 0012[108]
Performance

Maximum speed: 144 kn (166 mph, 267 km/h)
Cruise speed: 118 kn (136 mph, 219 km/h) for max range
Range: 542 nmi (625 mi, 1,005 km) with max fuel, 10% reserves
Service ceiling: 14,700 ft (4,480 m)
Rate of climb: 2,200 ft/min (11.2 m/s) at sea level
(All performance figures at weight of 20,500 lb (9,300 kg))
Armament
Up to 840 lb (380 kg) of weapons total
2× Mk 46/44 anti-submarine torpedoes (SH-3H)
Various sonobuoys and pyrotechnic devices
B57 nuclear depth charge