Sea Kings were designed to hunt Soviet submarines but their versatility expanded the mission set to presidents, oil fields, and airlines.
On March 11th 1959, the prototype Sikorsky SH-3 Sea King took flight for the first time. The Sea King and its derivatives have been hunting submarines, performing rescues, flying plane guard missions alongside aircraft carriers, shuttling American Presidents to and fro, plucking astronauts from the ocean after their return from space, and patrolling the seas from above, in the employ of dozens of nations, for 55 years and counting.
The impetus for the development of the SH-3 was submarines. Russian submarines, and lots of them. Fixed-wing aircraft, whether shore-based or carrier-based, are highly capable platforms but cannot prosecute a hostile submarine contact the same way a helicopter can. The Navy needed an improved anti-submarine helicopter to take over the missions performed by the piston-engine helo designs then in use.
The Navy observed the development of turboshaft engines with interest and approached Sikorsky with a requirement for an amphibious, twin-engine, turboshaft-powered helicopter that could take the in-close anti-submarine warfare (ASW) mission and run with it. Sikorsky delivered everything the Navy needed in the SH-3 Sea King.
Equipped with a dipping sonar, armed with aerial torpedoes and depth charges, and with all-weather mission endurance capability of more than four hours, the SH-3 became a ubiquitous sight on aircraft carriers and shore air stations almost immediately. Sikorsky developed every system in the rotorcraft, from landing gear to rotor hub and nose to tail feathers.
The twin-turboshaft power configuration of the SH-3 gave it enhanced reliability, increased payload capacity, and improved performance over single-engine rotorcraft. Carrier suitability trials conducted on board the aircraft carrier USS Lake Champlain (CVS-39) were completed by mid-1961. The trials included testing of the Sea King’s innovative automatic folding main rotor blades and tail assembly along with high-wind takeoffs and handling.
The Navy accepted the first operational SH-3As in September of 1961. At the time of its introduction, the Navy’s newest ASW helo was the largest amphibious helicopter in the world and the first operational turbine-powered, all-weather mission capable ASW rotorcraft in naval service.
Sikorsky continued to develop the SH-3 to enhance its capabilities, but right from the start they realized that the Sea King could be a workhorse for other friendly nations as well. Over the years the SH-3 (and its civil derivative, the S-61) has been license-built by other nations and utilized by scores of countries and companies.
Marine Corps squadron HMX-1 is the official “airline” of United States Presidents. Specially-equipped SH-3s have been shuttling Chief Executives and other VIPs to and from the White House lawn since 1962. When the President is on board the rotorcraft its call-sign changes to Marine One the same way the call-signs of the VC-25 Presidential transports do. Images of American Presidents boarding the green and white HMX-1 SH-3s at the White house are etched into the American consciousness.
About that amphibious capability. The Sea King is capable of landing on water, but it isn’t a common occurrence. The amphibious hull enables the SH-3 to make a water landing. Between the watertight hull and deployable airbags in sponsons mounted to either side of the forward fuselage, the Sea King can float upright. However, surface conditions and winds are critical factors when considering a landing on water. Of course the helo is equipped with conventional wheeled landing gear as well.
As time went by SH-3s were reworked and updated to include more powerful engines and defensive capabilities such as infrared countermeasures (IRCM) to improve battlefield survivability. Improved ASW sensor suites enabled Sea Kings coming out of rework to prosecute contacts more efficiently.
Like most Navy helicopters many SH-3s had equipment added, removed, or modified to adapt them for other missions like minesweeping, target drone recovery, SEAL team insertion and extraction, and vertical replenishment (VERTREP) of ships at sea. Later Sea King variants were equipped with digital navigation systems and specialized instrumentation and illumination for night vision compatibility. Not surprisingly, the helo aircrews adapted along with their steeds.
To perform its primary ASW mission, SH-3s carried up to four torpedoes or four depth charges. For anti-ship missions the Sea King has been adapted to fire up to two Sea Eagle or Exocet air-to-surface missiles. For when all other options fail, the SH-3 could also release the B57 nuclear depth bomb.
A typical SH-3 ASW equipment suite included the AQS-13 active/passive dipping sonar, computerized processing of sonar and sonobuoy data, various models of active and passive sonobuoys and the ARR-75 sonobuoy receiver, and the Magnetic Anomaly Detector (MAD). The onboard AKT-22 data link made it possible for the Sea King to share their “take” with other assets on-scene.
Even more adaptation to the basic SH-3 airframe resulted in the Air Force’s first dedicated rescue helicopters to see combat in Vietnam. The “Jolly Green Giant” HH-3s pioneered combat search and rescue (CSAR), flying deep-penetration rescue missions over hostile territory. Initial Air Force-specific CH-3 rotorcraft equipped with rear loading ramps, side sponsons, and tricycle landing gear were further modified to the HH-3E standard, specialized for CSAR by adding protective armor, an inflight refueling probe, a high-speed rescue hoist, self-sealing fuel tanks, auxiliary tanks, and plenty of firepower to fight their way into and out of hot pick-up zones.
The United States Coast Guard (USCG) adapted the HH-3 for their use as well. The HH-3F Pelican added search radar and the ability to land on water to the proven CH-3. USCG Pelicans have rescued hundreds since their introduction in 1965.
The Navy added protective armor, self-sealing fuel tanks, various defensive armament configurations, and other specialized equipment to several SH-3s during the Vietnam War. These Navy CSAR helos, designated HH-3A, flew their missions off ships of all sizes from destroyers to aircraft carriers and improvised the ability to refuel while hovering (HIFAR) above ships too small to accommodate the HH-3A on deck.
Beginning with the Mercury 7 in May of 1962, The Sea King was the primary helicopter for retrieving manned space vehicles after return to earth and splashdown. If you grew up during the 1960s and early 1970s you probably remember seeing all-white NAVY Sea Kings hovering over bobbing space capsules. SH-3s have also starred in movies like The Final Countdown (1980) and The Hunt For Red October (1990).
Time marches on and though the Sea King had served well, airframe fatigue and advancing technology caught up with them. Beginning during the 1990s the Navy’s SH-3s were gradually replaced by the many variants of the Sikorsky SH-60 Sea Hawk. The SH-3 still held down air station and navy yard SAR flight missions, logistical support and transport, and general “I-need-a-helo-now” utility roles. Naval Reserve units were equipped with Sea Kings well into the new century. But inevitably, on January 27th 2006, Helicopter Combat Support Squadron HC-2 ceremoniously retired the last operational US Navy SH-3s.
Foreign operators of the SH-3 include Argentina, Belgium, Brazil, Canada, Denmark, Germany, India, Iran, Iraq, Italy, Japan, Malaysia, Norway, Peru, Saudi Arabia, Spain, and Venezuela. The Sea King has been license-built by Agusta Helicopters in Italy, Mitsubishi Heavy Industries in Japan, and by Westland in the United Kingdom as the Westland Sea King. The major civil versions of the SH-3 are the S-61L and S-61N.
Current and former operators of the S-61 series of helicopters include Ansett-ANA in Australia, CHC Helicopters, Cougar Helicopters, Coulson Aircrane, Helijet, and the Canadian Coast Guard in Canada, Air Greenland, The Irish Coast Guard, Lebanon, KLM Helicopters in the Netherlands, Pakistan International Airlines, Bristow Helicopters, British Airways Helicopters, British International Helicopters, and Coast Guard in the U.K., AAR Corporation, Carson Helicopters, Croman Corporation, Helicopter Transport Services, Los Angeles Airways, New York Airways, San Francisco and Oakland Helicopter Airlines, and the United States Department of State in The United States.