Westland Sea King HC.4 above and 1 above
The helicopter most identified with U. S. long-range SAR operations in SEA first entered service as an ASW helicopter with the U. S. Navy. On March 11, 1959, Sikorsky Aircraft Corporation test pilots lifted off in the S-61, or H-3 Pelican, later known as the Sea King. The twin-engined, all weather Pelican became operational with the U. S. Navy in June 1961. The H-3, although designed primarily to detect, classify, track, and destroy enemy submarines, rapidly became a multipurpose ship or land-based aircraft with Navy, Marine, and USAF units. Powered by two GE T58-GE-10 1,250- horsepower turboshafts, soon upgraded to 1,400 horsepower, the H- 3 cruised at an airspeed of 120 knots to a maximum range of 542 nautical miles and reached a service ceiling of 14,700 feet. The H-3 had a maximum gross takeoff weight of 21,000 pounds, with the capability of a 6,000-pound slingload on some models.
Of conventional design, the Sea King’s five-bladed main rotor system measured 62 feet and its fuselage 54 feet, 9 inches. Designed for overwater flights the H-3 possessed emergency amphibious capabilities. The H-3 carried a crew of four and up to twenty-eight passengers in its transport configuration. For ASW operations the helicopter crew usually consisted of two pilots, two to three sensor operators, and up to three passengers. Dubbed the “Jolly Green Giant” by rescued aircrewmen, the USAF SAR version of the HH-3 usually carried two pilots, a door gunner, a parajumper (PJ), and a flight engineer who doubled as the rescue hoist operator. In 1967 two USAF Air Rescue and Recovery Service (ARRS) HH-3s demonstrated the viability of air refueling of helicopters by self-deploying from the United States to France in a flight of almost thirty-one hours (Pember 1998, 49).
Sikorsky produced two basic models of the S-61, the original with a watertight hull, which Navy personnel called “Big Mother,” and later, the elongated version with aft cargo doors and a loading ramp for larger cargo. The United States, Great Britain, Canada, Japan, Italy, Spain, Egypt, and Malaysia used several variants of the Sea King: search and rescue HH-3 and SH-3D also used to pluck U. S. Apollo astronauts and their space vehicles from the ocean after splashdown, ASW SH-3, tactical transport CH-3, mine sweeping RH-3, VIP transport VH-3 (used by the U. S. Marines to transport the president), special operations MH-3, and commercial transport helicopter. Armament included a dipping sonar, sonobuoys, magnetic anomaly detectors, two MK 46 torpedoes for ASW, and at least two 7.62-mm door-mounted miniguns on SAR helicopters for self-protection. The aircraft contained cockpit instrumentation for all-weather operations, including both search and weather radars. Later models included Doppler radar navigation systems. In the early 1990s many Sea Kings received upgraded T-58-GE-402 1,500- horsepower engines and global positioning systems (GPS). The USCG HH-3F had the capability to fly 300 miles, hover for twenty minutes, and return to base with fuel in reserve.
Sikorsky built more than 1,100 S-61s, while Westland, Mitsubishi, and Agusta manufactured over 400 versions of the H-3 under license. Westland installed a pair of Rolls Royce Gnome H. 1400 turboshafts and a Louis Newmark Mk 31 automatic flight control system in the British Sea Kings. The RN initially ordered fifty-six HAS1 Sea Kings, with 700(S) Squadron receiving the first for test and evaluation in August 1969. Testing resulted in the more powerful HAS2, and the HAS5 with a longer cabin to accommodate the Sea Searcher radar. Westland provided the Egyptian Air Force with a twenty-one-seat Sea King utility transport, minus the external floats, called the “Commando.” The British Royal Marines also ordered this version as the HC4, which conducted extensive combat operations in the Falklands War.
The last half of the 1960s provided additional milestones for Westland. On October 1, 1966, the company reorganized under the name Westland Helicopters Ltd. On the 8th of the previous month, under a licensing agreement, Westland began manufacturing the Sikorsky SH-3D Sea King as the HAS Mk 1, 2, 5, and 6, and the HAR Mk 3. Westland’s modifications included equipment upgrades to improve the Sea King’s utilization as an ASW platform and subsequent adaptations for SAR, commando insertions, and airborne electronic warfare (AEW). Westland’s Sea King rotor diameter measured 62 feet, and the helicopter 72 feet, 8 inches in length. Two Rolls-Royce Gnome 1400 1,500-horsepower turboshafts powered the aircraft to a speed of 114 knots; it had a maximum gross weight of 21,400 pounds. The ASW version carried a pilot and three system technicians, while the Commando version carried two pilots and up to twenty-eight troops to a maximum range of 600 nautical miles without refueling. Westland built a total of 330 of all versions.
Westland also produced a completely self-contained SAR helicopter that carried a crew of four, nine stretchers, a weather/search radar, smoke and flare dispensers, a flight director system with an auto hover mode, and folding blades for shipboard storage. The RAF made use of this version as the HAR Mk3 and the West German Navy as the Mk 41.
Westland exported Sea King variants to India, Norway, Belgium, Pakistan, Australia, and Qatar.
In 1967, Agusta opened another profitable line of helicopters by producing Sikorsky helicopters under a separate license agreement. The Italian Navy ordered twenty-six of the Agusta-manufactured Sikorsky Sea King (AS-61A-4) ASH-3Ds equipped with the AN/APN-195 radar installed in a nose radome and the APQ-706 Marte missile guidance radar mounted in a pod under the fuselage.
Agusta also produced two ASH-3D/TS VIP versions for the Italian government and the papacy. Agusta built a total of eighty Sea Kings, with sales to Libya, Peru, Iran, and Saudi Arabia.
Additionally, Agusta manufactured the Sikorsky HH-3F Pelican in search and rescue versions for the Italian military. The 15th Stormo received twenty of the aircraft and stationed them at bases along the Italian coast. SIAI also produced the HH-3F and the AB 205, AB 212, and, in the 1980s, the AB 412.
Sea King HAS.1
The first anti-submarine version for the Royal Navy, with Gnome H.1400 engines, a five-bladed tail rotor, a Plessey Type 195 dipping sonar and MEL ARI 5995 search radar in a dorsal radome. The Westland Sea King HAS.1 first flew on 7 May 1969. 56 built, many of which were converted to HAS.2.
Sea King HAS.2
Upgraded anti-submarine version for the Royal Navy, based on Australian Mk 50. More powerful Gnome H.1400-1 engines, six bladed tail rotor and upgraded avionics (including new Type 2069 dipping sonar), and improved navigation and communications equipment; 21 new build aircraft plus conversions from HAS.1s. Some were later converted for AEW (Airborne Early Warning) duties.
Sea King AEW.2
Conversion of Sea King HAS.1 or HAS.2s into AEW aircraft after lack of AEW cover was revealed during the Falklands War. Fitted with Thorn EMI Searchwater radar in inflatable radome, with sonar removed. Normally flown with three person (pilot and two observers) crew compared with four-person crew for ASW Sea Kings. Nine converted.
Sea King HAR.3
Search and rescue version for the Royal Air Force. Fitted with relocated rear cabin bulkhead giving greater cabin length, extra fuel and additional observation windows; 19 built.
Sea King HAR.3A
Improved search and rescue version of the Sea King HAR.3 for the Royal Air Force. Fitted with upgraded avionics; six built.
Sea King HC.4 / Westland Commando
Commando assault and utility transport version for the Royal Navy, with simplified undercarriage, and lengthened cabin. Capable of transporting 28 fully equipped troops; 42 built.
Sea King HC.4X
One aircraft first flown on 10 April 1989 for the Empire Test Pilots’ School.
Sea King Mk.4X
Two helicopters based on the HC.4 for trials/test beds at the Royal Aircraft Establishment at Farnborough. Fitted with various nose and/or dorsal sensor installations.
Sea King HAS.5
Upgraded anti-submarine warfare version for the Royal Navy, with longer range MEL Super Searcher radar in enlarged dorsal radome, new AQS902 acoustic processing system with provision to use sonobuoys. Entered service in June 1981; 30 new build aircraft plus about 55 converted from earlier versions. Some later converted into the HAR.5 for Search and Rescue.
Sea King HAR.5
Conversion of HAS.5 to search and rescue role for the Royal Navy, with ASW equipment removed but retaining Sea Searcher radar.
Sea King AEW.5
Four Sea King HAS.5s were converted into AEW helicopters for the Royal Navy.
Sea King HU.5
Surplus HAS.5 ASW helicopters converted into utility role for the Royal Navy.
Sea King HAS.6
Upgraded anti-submarine warfare version for the Royal Navy. fitted with improved avionics, with new sonar processor, improved tactical displays and better communications equipment; five new build aircraft plus conversions.
Sea King HAS.6(CR)
Five surplus HAS.6 ASW helicopters converted into the utility role for the Royal Navy. The last of the Royal Navy’s HAS.6(CR) helicopters was retired from service with 846 NAS on 31 March 2010.
Sea King ASaC7
Upgraded AEW2/5 for the Royal Navy with Searchwater 2000AEW replacing original Searchwater radar.
Sea King Mk.41
Search and rescue version of the Sea King HAS.1 for the German Navy, with longer cabin; 23 built, delivered between 1973 and 1975. A total of 20 were upgraded from 1986 onwards with additional Ferranti Seaspray radar in nose and capability to carry four Sea Skua Anti-ship missiles.
Sea King Mk.42
Anti-submarine warfare version of the Sea King HAS.1 for the Indian Navy; 12 built.
Sea King Mk.42A
Anti-submarine warfare version of the Sea King HAS.2 for the Indian Navy, fitted with haul-down system for operating from small ships; three built.
Sea King Mk.42B
Multi-purpose version for the Indian Navy, equipped for anti-submarine warfare, with dipping sonar and advanced avionics, and anti-shipping operations, with two Sea Eagle missiles; 21 built (one crashing before delivery).
Sea King Mk.42C
Search and rescue/utility transport version for the Indian Navy with nose mounted Bendix search radar; six built.
Sea King Mk.43
Search and rescue version of the Sea King HAS.1 for the Royal Norwegian Air Force, with lengthened cabin; 10 built.
Sea King Mk.43A
Uprated version of the Sea King Mk.43 for the Royal Norwegian Air Force, with airframe of Mk.2 but engines of Mk.1; single example built.
Sea King Mk.43B
Upgraded version of the Sea King Mk.43 for the Royal Norwegian Air Force. Upgraded avionics, including MEL Sea Searcher radar in large dorsal radome, weather radar in nose and FLIR turret under nose. Three new-build plus upgrade of remaining Mk.43 and Mk.43A helicopters.
Sea King Mk.45
Anti-submarine and anti-ship warfare version of the Sea King HAS.1 for the Pakistan Navy. Provision for carrying Exocet anti-ship missile; six built.
Sea King Mk.45A
One ex-Royal Navy Sea King HAS.5 helicopter was sold to Pakistan as an attrition replacement.
Sea King Mk.47
Anti-submarine version of the Sea King HAS.2 for the Egyptian Navy; six built.
Sea King Mk.48
Search and rescue version for the Belgian Air Force. Airframe similar to HAS.2 but with extended cabin; five built, delivered 1976. Retired in 2018.
Sea King Mk.50
Multi-role version for the Royal Australian Navy, equivalent to (but preceding) HAS.2; 10 built.
Sea King Mk.50A
Two improved Sea Kings were sold to the Royal Australian Navy as part of a follow-on order in 1981.
Sea King Mk.50B
Upgraded multi-role version for the Royal Australian Navy.
Minimum change assault and utility transport version for the Egyptian Air Force, with lengthened cabin but retaining sponsons with floatation gear; five built.
Improved assault and utility transport version for the Egyptian Air Force, fitted with more powerful engines, non-folding rotors and omitting undercarriage sponsons and floatation gear; 17 built.
Assault and utility transport version for the Qatar Emiri Air Force, almost identical to Egyptian Mk.2; three built.
VIP transport version of Commando Mk.2 for the Egyptian Air Force; two built.
VIP transport version of Commando Mk.2A for the Qatar Emiri Air Force; one built.
Electronic warfare version for the Egyptian Air Force, fitted with integrated ESM and jamming system, with radomes on side of fuselage; four built.
Anti-ship warfare version for the Qatar Emiri Air Force, fitted with dorsal radome and capable of carrying two Exocet missiles. Eight built.
Specifications (Sea King HAS.5)
Length: 55 ft 10 in (17.02 m) 
Height: 16 ft 10 in (5.13 m)
Empty weight: 14,051 lb (6,373 kg)
Gross weight: 21,000 lb (9,525 kg)
Max takeoff weight: 21,400 lb (9,707 kg)
Powerplant: 2 × Rolls-Royce H.1400-2 Gnome turboshaft engines, 1,660 shp (1,240 kW) each
Main rotor diameter: 62 ft 0 in (18.90 m)
Main rotor area: 3,020 sq ft (281 m2)
Blade section: NACA 0012
Cruise speed: 112 kn (129 mph, 207 km/h) (max cruise at sea level)
Range: 664 nmi (764 mi, 1,230 km)
Rate of climb: 2,020 ft/min (10.3 m/s)
4× Mark 44, Mark 46 or Sting Ray torpedoes, or 4× Depth charges
Provision for a door mounted machine gun of various calibers