Sikorsky SH-3 Sea King

Origins During the Cold War, the Soviet Navy built up a large and varied fleet of submarines which at one point was in excess of 200 operational submarines. The US Navy countered this threat by the improvement and development of various anti-submarine warfare (ASW) capabilities, which resulted in the development of the Sea King. During the late 1950s, the US Navy took advantage of recent aerospace advances, such as the turboshaft engine, by commissioning the development of a new large naval helicopter. Sikorsky received a request from the service to design a new turbine-powered helicopter that would be capable of performing the ASW mission. The specification included a dipping sonar, mission endurance of four hours, and the ability to support a weapons load of . In 1957, Sikorsky was awarded a contract to produce an all-weather amphibious helicopter for the US Navy. As per the earlier specification, this new rotorcraft was to excel at ASW; specifically, it would combine the roles of hunter and killer, as these two duties had previously been carried out by two separate helicopters. It was also the first helicopter to be procured under the US Navy's new weapon system concept, under which Sikorsky was responsible not only for the design and production of the airframe, but all major onboard systems, such as the sonar, navigational equipment, electronic devices, and support equipment. As such, the navigation suite for the rotorcraft was developed jointly by Sikorsky and the US Navy. Key features of the emerging ASW helicopter included its amphibious hull, which enabled the rotorcraft to readily perform water landings, and its adoption of a twin-turboshaft engine arrangement that enabled it to be larger, heavier and better-equipped than had been possible with prior helicopters. Into flight On 11 March 1959, the first prototype conducted its maiden flight. Shortly after the completion of suitability trials, the US Navy formally accepted delivery of the first HSS-2 rotorcraft, which was subsequently re-designated as the SH-3A, in September 1961. In late 1961 and early 1962, a modified US Navy HSS-2 Sea King was used to break the FAI 3 km, 100 km, 500 km and 1000 km helicopter speed records. This series of flights culminated on 5 February 1962 with the HSS-2 setting an absolute helicopter speed record of . This record was broken by a modified French Sud-Aviation Super Frelon helicopter on 23 July 1963 with a speed of . Further developments The base design of the Sea King had proved sound and several aspects were judged to be potentially useful for other operators, thus Sikorsky elected to pursue the further development of the rotorcraft for other markets beyond the US Navy. Another noteworthy Sea King variant, the significant change this time being the adoption of a conventional fuselage, the Sikorsky S-61R, was also concurrently developed for transport and search and rescue (SAR) duties, this type being extensively operated by the U.S. Air Force and the U.S. Coast Guard. In U.S. Navy service, the initial SH-3A model of the Sea King would be progressively converted into the improved SH-3D and SH-3H variants; these featured more powerful engines and improved sensors that gave the type greater operational capabilities as an ASW platform. It was also common for Sea Kings to be converted for non-ASW activities, these roles included minesweeping, combat search and rescue, and as a cargo/passenger utility transport. The NH-3A (S-61F) was an experimental high-speed compound helicopter based on the Sea King tested in the 1960s. Later modified with a tail rotor able to rotate 90° to serve as a pusher propeller; this helicopter demonstrated "Roto-Prop" pusher propeller for Sikorsky's S-66 design. : A minesweeper version of the Sea King for the U.S. Navy was made, with nine converted from SH-3A aircraft and then called the RH-3A. In contrast to the US Navy's Sea Kings, the Westland Sea King was intended for greater operational autonomy. In total, Westland produced 330 Sea Kings; outside of its British-based operators, various export customers were found for the Westland Sea King. including the Indian Naval Air Arm, the German Navy, the Royal Australian Navy, and the Royal Norwegian Air Force. While Sikorsky opted to terminate its own Sea King production line during the 1970s, the type has had a lengthy service life. In September 2009, it was reported that nearly 600 Sea Kings were believed to still be operational. ==Design==

The Sikorsky SH-3 Sea King is a twin-engine medium-sized amphibious rotorcraft. Many of the features on board the Sea King represented a considerable advancement over preceding helicopters. In addition to being fully amphibious and capable of operating under all weather conditions, it is the first operational American helicopter to be able to simultaneously hunt and destroy submarines. The powerplant used on the Sea King was the General Electric T58-GE-8B, which was initially capable of generating up to each. For search-and-rescue missions, the Sea King's cabin could accommodate up to 22 survivors. In a medical layout, a maximum of nine stretchers plus two medical officers could be carried. In the troop transport role, up to 28 soldiers can be accommodated. The Sea King features many design elements to support naval-orientated operations. The main rotor blades and the tail section can be folded via fully automated systems for storage on board ships. The hull design was compatible with landing on challenging terrain, including ice, snow, swamp land, and tundra. The Sea King could also be fitted to deploy the B57 nuclear bomb. ASW equipment used on Sea Kings has included the AQS-13A/B/E dipping sonar which included specialized computers for processing sonar and sonobuoy data, various models of sonobuoys, ARR-75 Sonobuoy Receivers, and the ASQ-81 magnetic anomaly detector. The commonly fitted AKT-22 data link enabled the rapid dissemination of sonar information to other friendly elements. Some later Sea King models featured the TACNAV digital navigation system (first generation GPS) and overhauled cockpit instrumentation for night vision compatibility. ==Operational history==

in San Diego, California, in 2003 During June 1961, the Sea King became operational with the US Navy as the HSS-2; at the time, it was not only the largest amphibious helicopter in the world, but was also the first all-weather rotorcraft to reach production status for the US Navy. The Sea King was able to operate from the flight decks of many of the US Navy's vessels as well as shore bases. It could also operate from offshore platforms to extend their surveillance and strike ranges. The type was capable of conducting nighttime ASW operations, albeit these usually posed considerable difficulty for the flight crew. The Sea King also performed various other roles and missions such as search-and-rescue, transport, anti-shipping and airborne early warning operations. Aircraft carriers would typically deploy Sea Kings to operate near the carrier as a plane guard, ready to rescue air crew who crashed during takeoff or landing. They were routinely used in a logistical capacity at sea, transferring personnel, mail, and other lighter cargoes between vessels. The Royal Canadian Navy (RCN) became a major operator of the Sikorsky CH-124 Sea King following its introduction to service in 1963. It remained Canada's dominant maritime helicopter for over 50 years, finally being withdrawn in 2018. One notable innovation in Canadian operations, which was subsequently adopted by several other nations, was the use of a winch 'hauldown' landing and securing method, referred to as a 'Beartrap'. This device considerably increased the ability of Sea Kings to land in difficult conditions, such as on small flight decks or during poor weather conditions. The Sea King was exported in large numbers to various nations, such as Brazil, Italy, Japan and the United Kingdom. Several operators have kept their Sea Kings in use for more than 50 years. During the Vietnam War, SH-3s rescued the crews of downed aircraft at sea and over land, typically being equipped with self-sealing fuel tanks, multiple machine guns and heavy armor when performing such missions. Due to the type's greater range and the safety of having two engines, it was often used during rescue sorties into North Vietnam to retrieve downed aircrew. Helicopter 66 was the primary recovery vehicle for Apollo missions 8 and 10 to 13. In February 1971, an SH-3A, operating from the amphibious assault ship USS New Orleans, recovered Apollo 14. A specialist search and rescue variant of the SH-3, the HH-3, also performed in this capacity. In 1992, the US Justice Department sued Sikorsky over allegations of overcharged component pricing and deliberately misleading US Navy negotiators. In 1997, the Justice Department issued further accusations against Sikorsky of willful overcharging on a contract to upgrade the Navy's Sea Kings. In 2024, the VH-3D was replaced by the VH-92 Patriot as the Marine One helicopter. During the 1990s, the Sea King was replaced in the ASW and SAR roles by the U.S. Navy with the newer Sikorsky SH-60 Sea Hawk. However, the SH-3 continued to operate in reserve units in roles including logistical support, search and rescue, and transport. On 27 January 2006, the SH-3 was ceremonially retired at NAS Norfolk, Virginia, by Helicopter Combat Support Squadron 2 (HC-2). They have been replaced by increasingly advanced variants of the SH-60 Sea Hawk. ==Variants==

. is in the background , a VH-3A "Sea King" that served in the Presidential fleet from 1961 to 1976, on permanent display at the Nixon Library US military ;XHSS-2: The only prototype of the H-3 Sea King. ;YHSS-2: Pre-production S-61 aircraft, seven built for the U.S. Navy, re-designated YSH-3A in 1962. ;NH-3A (S-61F): Experimental high-speed compound helicopter, with extensive streamlining, no floats, short wings carrying two turbojet engines for extra speed; one converted from SH-3A. Later modified with a tail rotor able to rotate 90° to serve as a pusher propeller; this helicopter demonstrated "Roto-Prop" pusher propeller for Sikorsky's S-66 design. ;SH-3G: Cargo, utility transport helicopter for the U.S. Navy. 105 conversions from SH-3A and SH-3D. ;S-61A-4 Nuri: Military transport, search and rescue helicopter for the Royal Malaysian Air Force. It can seat up to 31 combat troops. 38 built. United Aircraft of Canada ;CH-124: Anti-submarine warfare helicopter for the Royal Canadian Navy (41 assembled by United Aircraft of Canada). ;CH-124A: The Sea King Improvement Program (SKIP) added modernized avionics as well as improved safety features. ;ASH-3H: Anti-submarine warfare helicopter. Mitsubishi ;S-61A: License-built version of the S-61A as Search-and-Rescue and Utility helicopters for the Japan Maritime Self Defense Force. 18 built. ;HSS-2: License-built version of the S-61B as an anti-submarine warfare helicopter for the Japan Maritime Self Defense Force. 55 built. ;HSS-2A: License-built version of the S-61B (SH-3D) as an anti-submarine warfare helicopter for the Japan Maritime Self Defense Force. 28 built. ;HSS-2B: License-built version of the S-61B (SH-3H) as an anti-submarine warfare helicopter for the Japan Maritime Self Defense Force. 23 built. ==Operators==

Current ; • Argentine Naval Aviation ; • National Disaster Management Authority – An S-61A is leased from Cardig Air. ; • Iranian Navy • HMX-1 – transferred to Air Command in 1968 • Royal Canadian Air Force (See: CH-124 Sea King) – retired in December 2018 ; • Royal Danish Air Force ; • Indian Navy – replaced by Sea King 42C at INAS 350 to serve onboard . ; • Iraqi Air Force 's Rescue 5, flies offshore near Rancho Palos Verdes. ; • Italian Air Force – retired in September 2014 • Italian Navy ; • Japan Maritime Self Defense Force ; • Royal Malaysian Air Force – some helicopter transferred to Malaysian Army Aviation • Malaysian Army Aviation – ex-RMAF, was assigned to No. 882 Squadron. ; • Royal Saudi Air Force ; • Spanish Navy • United States Air Force • United States Navy ==Aircraft on display==

Argentina • 0675 – S-61D-4 on static display at the Argentine Naval Aviation Museum in Bahia Blanca, Buenos Aires. Denmark • U-240 – S-61A on static display at the Danmarks Flymuseum in Skjern, Central Denmark.. India • Saaras – UH-3H Sea king ASW preserved at beach road in Visakhapatnam. United States • 147140 – HH-3A on static display at the Pacific Missile Range Facility in Kekaha, Hawaii. • 148038 – UH-3A on static display at the Patuxent River Naval Air Museum in Lexington Park, Maryland. • 148042 – UH-3H on static display at Naval Station Norfolk in Norfolk, Virginia. • 148999 – SH-3H on static display at the USS Hornet Museum in Alameda, California. • 149006 – UH-3H on static display at the Evergreen Aviation & Space Museum in McMinnville, Oregon. It is painted as Apollo 11 recovery helicopter. • 149695 – SH-3G on static display at Naval Air Station Jacksonville in Jacksonville, Florida. • 149711 – SH-3H on static display at the USS Midway Museum in San Diego, California. • 149738 – SH-3H on static display at the Hickory Aviation Museum in Hickory, North Carolina. It was previously on display at the Quonset Air Museum in North Kingston, Rhode Island. • 149932 – SH-3G on static display at Patriots Point in Charleston, South Carolina. • 150611 – VH-3A on static display at the Ronald Reagan Presidential Library in Simi Valley, California. • 150613 – VH-3A on static display at the National Naval Aviation Museum in Pensacola, Florida. • 150617 – VH-3A on static display at the Richard Nixon Presidential Library and Museum in Yorba Linda, California. • 151556 – HH-3A on static display at the American Helicopter Museum & Education Center in West Chester, PA • 156484 – SH-3D on static display at the National Naval Aviation Museum in Pensacola, Florida. • 156501 – SH-3H on static display at Aviation Heritage Park in Bowling Green, Kentucky. • 159358 – VH-3D on static display at the George H.W. Bush Presidential Library and Museum in College Station, Texas. == Accidents and incidents ==

• Malaysia (Royal Malaysia Airforce) ==Specifications (SH-3D)==