In December 1957, the US Navy gave the go-ahead to a new programme for a very high performance helicopter with advanced technology, to replace the S-58 / HSS-1 and to combine the hunter/killer functions in one airframe. Sikorsky was approached again and submitted a project for a big twin turbine aircraft with a boat-type hull and retractable landing gear for amphibious operations. The aircraft had all-weather capability, a good choice of weapons loads and four hours’ endurance. The project was designated S-61.

Sikorsky S-61 / Westland Sea King / Commando Article

The main rotor of the medium-tonnage S-61 was of the articulated type, with five interchangeable blades which could be folded automatically by hydraulic actuators. The tail boom could also be folded for stowage on board ship. The all-metal, semi-monocoque single-step boat-type hull was amphibious, the twin mainwheels retracting into two sponsons.

The Sikorsky HSS-2 was the subject of a US Navy contract awarded on 23 September 1957. This called for an all-weather anti-submarine helicopter with ‘dunking sonar’ equipment and able to carry up to 381kg of offensive weapons. The S-61 design had watertight, hull-retractable landing gear in the stabilising floats, and was powered by two General Electric T58 turboshaft engines driving a five-bladed main rotor.

Design Features: Five-blade main and tail rotors. All-metal fully articulated oil-lubricated main rotor. Flanged cuffs on blades bolted to matching flanges on all-steel rotor head. Main rotor blades are interchangeable and are provided with an automatic powered folding system. Rotor brake standard. All-metal tail rotor. Non-folding blades on S-61L and S-61N. Fixed stabiliser on starboard side of tail section. A rotor brake is standard.

The amphibious landing gear consists of two twin-wheel main units, which are retracted rearward hydraulically into stabilising floats, and non-retractable tailwheel. Oleo-pneumatic shock-absorbers. Goodyear mainwheels and tubeless tyres size 6.50 x 10 type III, pressure 4.92kg/csq.m. Goodyear tailwheel and tyre size 6.00 x 6. Goodyear hydraulic disc brakes. Boat hull and pop-out flotation bags in stabilising floats permit emergency operation from water. Non-retractable landing gear on S-61L.

Pilot and co-pilot on flight deck, two sonar operators in main cabin. Dual controls. Crew entry door at rear of flight deck on port side. Large loading door at rear of cabin on starboard side. Crew of three: pilot, co-pilot and flight attendant on S-61L. Main cabin accommodates up to 30 passengers. Standard arrangement has eight single seats and one double seat on port side of cabin, seven double seats on starboard side and one double seat at rear. Rear seat may be replaced by a toilet.

Primary and auxiliary hydraulic systems, pressure 105kg/sq.cm, for flying controls. Utility hydraulic system, pressure 210kg/sq.cm, for landing gear, winches and blade folding. Pneumatic system, pressure 210kg/sq.cm, for blow-down emergency landing gear extension. Electrical system includes one 300A DC generator, two 20kVA 115A AC generators and 24V 22A battery. APU optional.

AlliedSignal AQS-13 sonar with 180 degree search beam width. Hamilton Standard autostabilisation equipment. Automatic transition into hover. Sonar coupler holds altitude automatically in conjunction with Ryan APN-130 Doppler radar and radar altimeter. Provision for 272kg capacity rescue hoist and 3,630kg capacity automatic touchdown-release low-response cargo sling for external loads.

Provision for 381kg of weapons, including homing torpedoes.

The prototype HSS-2 flew on 11 March 1959 and ten pre-production YHSS-2 trials aircraft (147137 to 147146) followed completing service trials in 1960. During flight testing, it proved its ability to hover over one point for more than three hours continuously, and to complete patrols of up to four hours with large fuel reserves. Redesignated as YSH-34A in 1962.

The US Navy ordered the first ten S-61B/HSS-2 for delivery starting in September 1961 and the Sea King began to reach fleet squadrons in September 1961. The helicopters were later redesignated SH-3A Sea King. One of the first production models set up a world speed record of 339 km/h on 5 February 1962. The HSS-2 held all four of the other major international helicopter speed records for distances up to 620 miles.

In the SH-3A version 255 were produced, while eight more (150610 to 150617), ordered as HSS-2Z and subsequently re-designated VH-3A and -3C, were assigned to the special American Presidential Department for personnel transport and evacuation services in case of emergency. First flying on 18 September 1962 eight modifications were produced (147141, and 150610-150617) and 11 new production (159350-159360).

The YSH-3A Sea King and SH-3A were USN anti-sub warfare helicopters. About 250 were built, including 148038, 152104/152139, and 153532/153537, of which one was converted with a modified fuselage to S-61F, three as CH-3B, and three to the USAF as NSH-3A (62-12571/12573).

One set a world helicopter speed record of 192.9mph on 17 May 1961, piloted by P L Sullivan and B W Witherspoon. A highly modified SH-3A set a world helicopter speed record of 210.64mph on 5 February 1962 piloted by R Grafton.

Nine of the SH-3As were transformed into RH-3As with minesweeping equipment, first flying on 2 February 1965, and three were used by the USAF for missile site support and drone recovery. They were the only H-3 to have cargo doors on both sides. A small number of RH-3A minesweeper variants entered service in 1964. Some were to became UH-3A drone targets. Repowered RH-3A were designated RH-3D.

Another 12 SH-3As were converted into the HH-3A for battlefield rescue work, and were fitted with two Emerson TAT-102 turrets mounted at the rear of the two spontoons, and an in-flight refuelling probe.

The H-3 designation was applied to various versions of the S-61 basic design, including S-61B, -61D, -61F, and -61R.

The HH 3E of the USAF Aerospace Rescue and Recovery Service has an inflight refuelling probe, hoist and much special role gear, and has also been developed into the radar equipped HH 3F Pelican advanced search and-rescue helicopter for the US Coast Guard.

In April 1962, the USAF leased HSS-2 / CH-3B (62-12574 to 62-12576), transformed into 27-seat transport aircraft for services linking the Texas Towers radar installations. Another three S-61As upgraded to CH-3B were purchased for this purpose (62-12571 to 62-12573). One later transferred to the USN. Until 1990, the Library of the USAF Museum erroneously filed details of these aircraft under the H-38 designation.

Sixteen S-61A-4s with 31 seats were acquired by the Royal Malaysian Air Force (S-61A-4 Nuri) and nine by the Danish Air Force for rescue work. Danish deliveries were made from December 1964 to May 1965. One went to a civil operator. A total of 38 S-61A were built.

A 1965 S-61F experimental version of the S-61 to test high speeds reached 390 km/h.

From 1966, the anti-sub SH-3A was superseded by the SH-3D, which had a 1044kW / 1419shp T58-GE-10 turbine replacing the original 932kW T58-GE-8Bs, and new electronics. Seventy-two were built; prototype 152139, 152690/152713, 154100/154123, 156483/156506, 158724/158725, 158874/158875, 159026/159029, 159053/159056, and 161207/161212. In addition, several SH-3As were converted to this standard (148998, 151544, 152139, and 153532/153537). VH-3D referred to a conversion.

The first SH-3D delivered in June 1966 was one of six ordered by the Spanish Navy. This was followed by another four for the Brazilian Navy and 73 for the US Navy, and ordered by Argentina.

The 105 SH-3G were USN SH-3A and -3B converted to utility configuration. They were further modified as SH-3H with new anti-sub warfare equipment fitted and UH-3H.

Two SH-3Gs were converted to YSH-3J as prototypes for the LAMPS III program.

The essentially similar CH-124, assembled by United Aircraft of Canada, was supplied to the Canadian navy. The Royal Canadian Navy was the first export customer, ordering 41 of the type. The Royal Norwegian air force acquired S-61A helicopters without ASW equipment for rescue duties, and the Royal Malaysian air force acquired S-61A-4 Nuri helicopters equipped to carry 31 troops or operate in the SAR role.

One hundred and sixty-seven HSS-2, HSS-2A, SH-3D. HSS-2Bs (SH-3H) and a further 18 SAR-configured S-61As were built under licence by Mitsubishi, in a programme which was completed in 1990.

The SH-3H was the standard version in service with the US Navy, with approximately 150 earlier aircraft modified to this standard. Supplemented by small numbers of the surviving SH-3G utility version, which has had all the SH-3H’s anti-submarine equipment removed, SH-3Hs serve regularly on board the Navy’s carriers and at shore bases, but were replaced by the SH-60 Seahawk and Ocean Hawk. Eight of the SH-3s supplied to Spain were modified to SH-3H standard, and three of these were equipped with a Thorn-EMI Searchwater radar in an external inflatable radome (similar to that fitted to Royal Navy Sea King AEW.Mk 3s) for shipboard airborne early warning duties.

Acquired originally for re-supply of its radar stations, the US Air Force CH-3B was essentially a de-navalised SH-3, but the CH-3C that was ordered in November 1962 introduced a number of major changes, including a rear loading ramp.

Originally conceived as XHR3S-1 and allocated the company designation S-61R, the prototype flew on 17 June 1963 and the first CH-3C delivery was made on 30 December 1963. The small flotation sponsons were replaced by larger sponsons and the tail wheel was replaced by a retractable nose wheel. Only one S-61R was built for civilian use and seventy-five CH-3C models were built for the USAF (62-12561/12570, -12577/12582, 63-9676/9691, 64-14221/14237, 65-5690/5700, -12511, and -12777/1280). The R model has an 80 hp auxiliary power unit. An engine change from 969kW T58-GE-1s to 1119kW T58-GE-5S produced the CH-3E in February 1966. Most were later converted to CH-3E or HH-3E standards.

One CH-3C (62-12581) was temporarily used to test de-icing equipment as CH-3C.

Some were later converted to HH-3E standard for the USAF Aerospace Rescue and Recovery Service, being provided with armour, self-sealing fuel tanks, retractable inflight-refuelling probe, rescue hoist and 12.7mm machine-guns for defensive purposes; this was the ‘Jolly Green Giant’ as used in Vietnam. These aircraft have all been replaced by the HH-60. The US Coast Guard operated the HH-3F Pelican, which had advanced electronic equipment for SAR duties, but lacked the self-sealing tanks, armour and armament of the HH-3E. Ordered in August 1965, the US Coast Guard a special version gave all-weather capability, which could safely land on water. The Pelican was virtually identical to the HH-3E, apart from the lack of protection, armament and other military equipment. It had an AN/APN-195 search radar on the port side of the nose. Forty were operated; 1430/1438, 1467/1497 plus 12 USN (158847/158858). These gave way to the HH-60J Jayhawk.

A heavylift version of this helicopter, nicknamed the ‘Payloader’, carried cargoes as heavy as 4990kg.
The SH-3 has been replaced by aboard USN carriers by the SH-60F Sea Hawk.

A total of 210 HSS-2 were built (148033 to 148052, 148964 to 149012, 149679 to 149738, 149893 to 149934, 150618 to 150620, and 151522 to 151557) powered by two T58-GE-8 engines. Production continued as SH-3A and ultimately 245 were built.

Civil versions for passenger operations were developed initially as the non-amphibious S-61L which, with a lengthened fuselage to seat up to 30 passengers, was first flown on 6 December 1960 and was FAA-approved on 2 November 1961. S-61Ls entered service with Los Angeles Airways on 1 March 1962. The S-61L is a landplane model, although its hull is sealed against the possibility of making an emergency landing on water, and all undercarriage units are non-retracting. It seats 28 passengers in the standard airline seating layout and carries a flight crew of 3.

Three S 61Ls operated by Los Angeles Airways had each exceeded 10,000 flight hours by February 1968.

Three S 61L was followed by the essentially similar S-61N that was, however, an amphibious version with a sealed hull and stabilising floats that housed retractable landing gear; it was first flown on 7 August 1962 and is still in widespread civil use. The type received FAA certification – the first for a twin-turbine commercial helicopter – in November 1961 and since October 1964 has been cleared for all-weather operation. Production examples have 1500shp CT58-140 shaft turbines.

Customers up to January 1968 for the S-61N have been British European Airways (four); Greenlandair (four); Pakistan International and San Francisco & Oakland (three each); Helibuss of Norway (two); and Ansett/A.N.A., Brunei Shell Petroleum, the Canadian Dept. of Transport, Elivie of Italy, Japan Air Lines, KLM, Nitto Airways and Petroleum Helicopters Inc. (one each).

BEA used a sole S-61N on the 35 mile route between Land’s End and the Scilly Isles.

The S-61N is the civil version of the military S-61C, and is some four foot longer. The sole example was used by Grumman Corp for many years in support of flight operations from Long Island.

The S-61R differs from the original S-61 in that it has a more boat-type hull, modified to take a rear loading ramp, while the two sponsons have been replaced by two stub wings set farther back, into which the rear members of the tricycle landing gear retract.

The prototype was built by the company as a private venture and flown with a civil registration on 17 June 1963, almost one month ahead of schedule. However, the USAF had already placed an order with Sikorsky in February of that year for 22 aircraft, designated CH-3C, and they began to receive the first helicopters at the end of 1963. Subsequent orders brought the total number for the USAF to 133.

The CH-3C was used in the Vietnam War for rescuing pilots who had been shot down and came to be nicknamed the “Jolly Green Giant”. It was given more powerful T58-GE-5 turbines from February 1965 and redesignated CH-3E. The uprated “Green Giant” could carry 26 troops or 15 wounded, or vehicles of equivalent weight, and could also be armed with two Emerson turrets on the leading edges of the two stub wings.

Forty-two CH-3Es were built (66-13291/13296, 67-14702/14725, and 69-5798/5812), in addition to which 41 CH-3Cs were modified to this standard.

The USAF also asked for specific modifications to be made to this helicopter to meet the demands of the Vietnam War: application of armour; use of supplementary fuel tanks for extended flights; self-sealing internal fuel tanks and a telescopic in-flight refuelling probe. Two of the first aircraft of the 50 to be built in the HH-3E rescue version became famous in 1967 by flying non-stop from New York to Paris (for the Air Show), covering the 6870km journey with nine refuellings by airtankers. Eleven were converted from CH-3E (66-13284/13290, and 68-8282), plus several CH-3Cs.

The CH-3E could seat up to 30 troops or carry 2270kg of cargo.

In 1975 CH/HH-3Es became the first helicopters in the US Air National Guard. Variants of Sikorsky’s S-70 have replaced S-61Rs in US service.

S-61 production by Sikorsky came to an end after two decades on 19 June 1980 and military S-61s served in 30 countries, plus with the US Air Force, Navy, Marine Corps and Coast Guard. Sikorsky built 794 S-61s between 1959 and 1980.

Orlando Helicopters provided extensive spares support for the S-61 and is investigating ways to re-engine existing aircraft to run on alternative petrol, propane and alcohol fuels.

Carson Helicopters have been modifying various versions of the H-3 and HH-3, as S-61A models. This involves the fitting of composite blades.

In response to a Japanese naval specification, Mitsubishi obtained a license to produce the S-61; three were purchased directly from Sikorsky and by February 1972, 43 locally-produced aircraft had been delivered. The first models were assembled from US-built fuselages, rotors, and other components with Mistubishi subsequrntly producing more parts. Procurement in the FY1987 budget amounting to 17 of the HSS-2B variant. HSS-2 deliveries from the Japanese production line began in 1964, and 138 had been completed by mid-1985, some with Marte anti-ship missile armament.

Since 1967 Agusta has been building SH-3Ds under licence in Italy as the Agusta-Sikorsky ASH-3D Silver, following an Italian naval order for an ASW helicopter to replace the old Sikorsky SH-34. An initial batch of 24 was built for the Italian Navy and 20 for the Iranian Navy (three in the VIP version). The Italian SH-3D is identical to the American model, apart from the installation of a Teledyne Doppler radar and a search radar on the left side of the nose. Some 105 ASH-3As with ASW equipment removed were redesignated SH-3G for utility duties, while further conversions which have been made since 1971 are of the SH-3H version, with updated ASW and electronic surveillance equipment.

The only foreign license-holder for the S-61R / CH-3 / HH-3 was Agusta, who began producing it in 1974. The 22 aircraft built by Agusta were all delivered to the Italian Air Force as replacements for the amphibious Grumman Albatross used for search and rescue missions at sea.

Agusta 1974 production was the HH-3F (S-61R). Production of the HH-3F Combat SAR version lasted into mid-1990s.

When production of the AS-61 and ASH-3D, ASH-3TS (Transporto Special, a VIP version) and ASH-3H ceased, Agusta claimed it could re-open the line in 36 months. The Italian firm did recommence building AS-61R (HH-3F) search and rescue helicopters to meet an order for two from the national civil protection service and 13 for the air force. These have upgraded radar, LORAN, FLIR and navigation systems, modifications that were to be retrofitted to the air force’s existing 19 AS-61Rs. Agusta is also the exclusive overhaul and repair agent for Europe and the Mediterranean.

Agusta continued limited production of SH-3 helicopters under licence from Sikorsky in 1987. The ASH-3D/TS is a VIP transport variant, while the naval model is the ASH-3H, which may be used in the ASW/ASV, electronic warfare, SAR, and tactical transport roles. An ASH-3H was to be used to test the British Aerospace/Bendix Helras sonar equipment for the forthcoming EH.101.

Argentina is unique in that it operates both Sikorsky and Agusta built examples.

In Britian, the Royal Navy also chose the S-61 to replace its Wessex. In 1959 Westland acquired the license to build the Sikorsky S-61B, to replace the Wessex in the antisubmarine role. The licence agreement allowed Westland to use the airframe and rotor system of the Sikorsky SH-3 Sea King as the basis for a new ASW helicopter for the Royal Navy. The Royal Navy specification called for a British powerplant with different characteristics from the original one, different electronics and a wide range of mission capabilities. Westland adopted a pair of Rolls-Royce Bristol Gnome turbines for their version of the Sea King, with fully computerized controls and largely British-made ASW equipment. The resultant helicopter is readily identifiable by the dorsal radome of the all-weather search radar. Other avionics systems include Plessey dipping sonar, Marconi Doppler navigation radar and Sperry & New-mark instrumentation.

Following test and evaluation of prototype and pre-production aircraft assembled from Sikorsky-built components, the first British-built HAS Mk.1 production Sea King flew on 7 May 1969 and the first squadrons were formed the following August. At that time, the Sea King HAS.Mk 1 was similar to the Sikorsky SH 3D Sea King, but powerplant comprised two Rolls-Royce Gnome H.1400 turboshaft engines. More significantly, Westland had adapted the large cabin as a tactical compartment for ASW operations, this meaning that the British Sea King was able to operate as an independent unit in an ASW role.

The Sea King is not a truly amphibious vehicle, in that any length of time spent in water would irrevocably damage some items of equipment on the hull. It is therefore only designed to land on water in an emergency, the boat-type hull being guaranteed watertight for 15 minutes. The two lateral sponsons contain flotation bags to improve buoyancy.

Westland delivered 56 in 1969 72. The HAS.Mk 1 machines were later modified to Sea King HAS.Mk 2 standard with more powerful Rolls Royce Gnome engines improved equipment, 21 Sea King HAS.Mk 2 helicopters also being built new.

The Sea King HAS.Mk 3 is the RAF search and rescue model with very complete equipment and versatility (SAR models carry up to 22 rescues including stretcher casualties).

The Sea King HC.Mk.4 is the ver¬sion of the Command for the Royal Navy (used for Royal Marine assault transport) with the shipboard features (such as folding blades and tail) but simple fixed landing gear and fitted for 27 troops or 6, 000 lb (2722 kg) of cargo. The Sea King HAS.Mk.5 was a RN ASW model with dramatically up rated avionics, all Sea King HAS.Mk.2s being converted to this standard; 17 were built new and after the Falklands nine more were ordered, The Royal Navy received a small number of Sea King AEW helicopters in response to a need appreciated in the Falklands war of 1982. This model had Thorn EMI Searchwater radar with its antenna in an inflated and swivelling radome pro¬jecting from the right side of the fusel¬age. Key items in the Sea King HAS.Mk.5’s avionics suite are the MEL Sea Searcher surveillance radar with a radome of considerably different shape and size, provision for the launch of passive sonobuoys, LAPADS (Lightweight Acoustic Processing and Display System) by Marconi for the quicker and more precise handling of acoustic data, and a better display sys¬tem. To permit the installation of the extra equipment, the cabin was extended aft by 1.83 m (6 ft), Westland have exported ASW and SAR Sea Kings (including the upgraded Sea King Mk.50 with Bendix sonar for Au¬stralia) to eight countries.

The first of two Westland Sea King Mk.50A for the Australian Navy was shipped to Australia in February 1983 and officially delivered to the RAN on 26 January.

The Royal Navy has ordered seven examples of an advanced version of the Sea King, the HAS.6, for service from 1989 in the ASW/ASV role. The HAS.6 is powered by uprated 1092kW Gnome H.1400-1T engines, and has advanced-design composite main and tail rotors, an uprated gearbox, improved radar, and Sea Eagle ASM armament. The HAS.6 will join the current fleet of HAS.5s, which have MEL Sea Searcher radar in an enlarged dorsal radome, Tans G coupled to Decca 71 Doppler, and GEC Avionics Lapads acoustic processing equipment for both sonar and dunking sonar. Earlier Sea King HAS.2s have been upgraded to HAS.5 standard.

Essentially the same as the HAS.6 are the 20 Sea King Mk.42Bs ordered for the Indian Navy, which will also be equipped with Sea Eagles and a GEC Avionics AQS-902 acoustic processing system. The Indian Navy has received the first of six Mk.42C utility variants of the advanced Sea King, with nose mounted Bendix RDR-1400C radar.

An AEW Sea King, equipped with a Thorn-EMI Searchwater maritime surveillance radar in a retractable radome, has been operational since November 1984. The Searchwater radar gives a 360 degree scan with a multiple target track-while-scan capability. Ten Sea King AEW.2s were being acquired, all converted HAS.2 airframes. Fitted with Thorn-EMI Searchwater surveillance radars during the Falklands war, some have been designated AEW.2As. The AEW7 being based around the Searchwater 2000 radar.

Westland has built over 200 Sea Kings, including the Sea King Mk.1, 2 and 5 for the Royal Navy, 22 for the German Navy (Mk.41), 11 for the Norwegian Air Force (Mk.43) and 12 for the Australian Navy (Mk.50).

Westland also produces a tactical transport version of the Sea King, known as the Commando, which first flew on 12 September 1973. It has the same power plant as the Sea King, a fixed landing gear, can carry up to 28 troops or 2,720kg of cargo, and may be armed for assault duties. The Commando Mk 1 is also known as the Sea King Mk 70 and is basically a stripped-out Sea King HAS.Mk 1.

Westland flew the first commando Mk 2 on 16 January 1975. No customer has ever specified the Mk 2’s optional underwing hardpoints. Commando Mk 2Bs have extra seats for two flight attendants.

Commando Mk 1 and Mk 2 versions have been supplied to Egypt and Qatar. Qatar’s Mk 3s have Sea King-like undercarriage sponsons. 17 were initially delivered to the Royal Navy and at least another 30 to Egypt and Qatar.

Deliveries for the Sea King and Commando totalled 326 by the end of 1993.

Gallery

Versions:

S-61A
Amphibious transport, generally similar to the US Navy’s SH-3A. Accommodation for 26 troops, 15 litters, cargo, or 12 passengers in VIP configuration. General Electric T58 turboshaft engines standard, but Rolls-Royce Gnome H.1200 offered as alternative.

ASH-3 Sea King

S-61A-4
Export version for Malaysia; first ordered on 26 October 1970, known locally as Nuri.

S-61B
Initial production version with amphibious capability.

S-61D
Export version of SH-3D.

S-61D-4
For Argentine Navy; ordered in 1971.

S-61F
Experimental high-speed version with stub wings and auxiliary turbojets.

S-61L
Non-amphibious commercial version with modified landing gear, rotor head and stabiliser. First flight of prototype 6 December 1960; FAA certification 2 November 1961.

S-61L Mk II
Improved version with more powerful 1,118 kW (1,500 shp) CT58-140-2 turboshaft engines; individual cargo bins; enhanced vibration damping. Accommodation increased to 30 passengers.

S-61N
Similar to S-61L, but with sealed hull and stabilising floats (as on SH-3A) for amphibious operations. First flight 7 August 1962.

S-61N Mk II
Improved version with more powerful CT58-140-2 engines; individual cargo bins; enhanced vibration damping. Accommodation increased to 26 passengers.

S-61R
Development of S-61B; introduced many design changes, including rear loading ramp and new landing gear.

AS-61N1 Silver
Licence-built version of S-61N, with slightly shorter fuselage and greater range, by Agusta in Italy.

AS-61R Pelican
Licence-built multipurpose SAR version by Agusta in Italy.

ASH-3D/TS
Licence-built VIP transport version by Agusta in Italy.

ASH-3D
Licence-built multirole naval version built by Agusta in Italy.

CH-3B
Version of S-61A operated by USAF for missile site support and drone recovery duties.

CH-3C/E
Transport version of S-61R for USAF.

CH-124 / CHSS-2
Anti-submarine helicopter similar to SH-3A, delivered to the Canadian forces in May 1963.

HH-3A
Modified version of SH-3A for Search and Rescue duties, with T58-GE-8F turboshaft engines, two electrically powered minigun turrets, high-speed refuelling and dumping system, rescue hoist, upgraded avionics, external auxiliary fuel tanks and armour installation.

HH-3E
Version of S-61R for US Aerospace rescue and recovery service.

HH-3F
Version of S-61R for US Coast Guard.

RH-3A
Conversion of nine SH-3As for mine countermeasures duty with US Navy.

SH-3A / HSS-2 Sea King
Initial amphibious ASW version for US Navy; powered by 932kW General Electric T58-GE-8B turboshaft engines.

SH-3D Sea King
More powerful ASW development of SH-3A for US Navy, with 1,043kW T58-GE-10 engines and an additional 530 litres of fuel. First delivered in 1966.

SH-3G
US Navy conversion of 105 SH-3As into utility helicopters. Six equipped with minigun pods for SAR missions.

SH-3H
Multipurpose version of SH-3A and SH-3G with two T58-GE-10 turboshafts; later converted for ASW and anti-missile operations, including lightweight sonar, active and passive sonar buoys, magnetic anomaly detection equipment and radar.

UH-3A
Utility version with T58-GE-8B turboshafts.

VH-3A / HSS-2Z
Passenger transport version of SH-3A, used on VIP and emergency evacuation for US President and other key personnel.

VH-3D
Passenger transport version of SH-3D.

Westland Commando
Licence-produced UK version.

Westland Sea King
Licence-produced UK version.

Sea King HAS.Mk 1
Initial ASW version for Royal Navy; since updated to Sea King HAS.Mk 2 by Royal Navy; 56 completed

Sea King HAS.Mk 2
ASW/SAR version for Royal Navy with uprated Gnome H.1400-1 turboshafts; 21 completed

Sea King HAR.Mk 3
SAR version for Royal Air Force with Gnome H.1400-1 turboshafts; 16 delivered in 1979 plus three in 1985; upgraded to

HAR.Mk 3A
Standard through addition of greatly improved avionics, navigation and communications gear

Sea King HC.Mk 4
Version of Commando Mk 2 for Royal Navy; combines folding rotor and tail of Sea King, non-retractable landing gear of Commando and Gnome H.1400-1 turboshafts; last aircraft delivered in 1990, total production 89; some aircraft modified with RWR, missile approach warning system, chaff/flare dispensers, tactical navigation equipment, and NVG cockpit for Gulf War operations

Sea King Mk 4X
Two aircraft, basically as HC.Mk 4; for development use by RAE Famborough

Sea King HAS.Mk 5
Developed ASW/SAR version for Royal Navy with Gnome H. 1400-1 engines and advanced avionics; all Sea King HAS.Mk 2 aircraft upgraded to this standard along with 30 new-build aircraft delivered between 1980 and 1986

Sea King HAS.Mk 6
Substantially improved anti-submarine warfare version for Royal Navy comprising five conversions from Mk 5 standard and 25 new aircraft

Sea King Mk 41
SAR version for Federal German navy with H.1400 turboshafts – 22 built

Sea King Mk 42
ASW version for Indian navy with H.1400 turboshafts – 24 built based on the RN version except for the communications equipment

Sea King Mk 42A
ASW version for Indian navy with H.1400-1 turboshafts

Sea King Mk 42B
Anti-ship version for Indian navy, H 1400-1 turboshafts and equipped to carry Sea Eagle missiles

Sea King Mk 43
SAR version for Norwegian air force with H.1400 turboshafts – 11 built

Sea King Mk 43A
SAR version for Norwegian air force with H. 1400-1 turboshafts

Sea King Mk 45
ASW version for Pakistan navy with H.1400 turboshafts – 6 built

Sea King Mk 47
ASW version with H.1400-1 turboshafts, ordered by Saudi Arabia for Egyptian navy

Sea King Mk 48
SAR version for Belgian air force with H.1400-1 turboshafts – 5 built

Sea King Mk 50
Multi-role version for Royal Australian Navy; developed from Sea King HAS.Mk 1 but with H. 1400-1 turboshafts; two additional but similar aircraft ordered in 1983 were allocated designation Sea King Mk 50A

• 12 built

Commando Mk 1
Version with H.1400 turboshafts ordered by Saudi Arabia for Egyptian air force

Commando Mk 2
Version with H. 1400-1 turboshafts for Egyptian air force

Commando Mk 2A
Version as Commando Mk 2 for Qatar Emiri air force

Commando Mk 2B
Version as Commando Mk 2 with VIP interiors for Egyptian air force

Commando Mk 2C
Version as Commando Mk 2B for Qatar Emiri air force

Specifications

HSS-2
Engines: 2 x 1250 shp General Electric T-58-GE-8.
Main rotor diameter: 62 ft
Main rotor disc area: 3019 sq.ft
Length: 54 ft 9 in
Width over floats: 15 ft 8 in
Empty weight: 11,194 lb
Normal takeoff weight: 17,768 lb
Fuel capacity: 575 gal
Max speed: 148 mph at SL
Hover ceiling OGE: 6000 ft
Range: 535 mi
Weapon load: 840 lb

S 61L
Engine: 2 x General Electric CT58-140-2 turboshaft, 1,118kW / 1500 shp
Rotor dia: 62 ft 0 in (18.9 m)
Length: 72 ft 7 in (22.12 m)
Height: 17 ft (5.18 m)
Max TO wt: 19,000 lb (8620kg)
Max level speed: 146 mph (235 kph)
Fuel: Forward 796 litres, 757 litres.
Total fuel capacity 1,553 lt
Range: 292 mi
Passenger capacity: 30

S-61N
Engine: 2 x General Electric CT58-110-1 turboshaft, 1000kW
Main rotor diameter: 18.9m
Fuselage length: 18.08m, height: 5.32m, take-off weight: 8618kg, max speed at sea level: 241km/h, ceiling: 3505m, range with max fuel: 443km

S-61N
Engines: 2 x General Electric CT58-140-2, 1,118kW / 1500 shp each
MAUW: 19,000 lb
Empty wt: 12,500 lb
Rotor dia: 62 ft
Disc loading: 6.3 lb/sq.ft
Pwr loading: 7.6 lb/hp
Length: 73 ft
Height: 18.5 ft
Cruise: 120-130 kt
Fuel flow @ cruise: 1050 lbs/hr
Equipped useful load: 6515 lb
Payload max fuel: 2068 lb
Range max fuel/ cruise: 533 nm/ 3.4 hr
Service ceiling: 12,500 ft
Range: 4 hr / 460 nm
Pax cap: 25
ROC: 1300 fpm
HIGE: 8700 ft
HOGE: 3800 ft
Max sling load: 8000 lb
Fuel cap: 2788/4447 lb
Fuel: Forward 796 litres, 757 litres. Total fuel capacity 1,553 lt
Opt fuel: 924 litre

S-61R

YHSS-2
Engines: two General Electric T58-GE-6
Rotor diameter: 62’0″
Length 54’9″
Max speed: 166 mph

H-3 (Model S-61)
Engines: two GE T58-GE-8C/F turboshafts
Main rotor: six-blade
Main rotor diameter: 62’0″
Length: 54’9″
Max speed: 160 mph
Cruise: 133 mph
Range: 625 mi
Ceiling: 10,800′

CH-3C
Engines: 2 x General Electric CT58-GE-1, 1300 shp / 969kW
Main rotor diameter: 18.90m
Fuselage length: 17.45m
Height: 5.51m
Max take-off weight: 9750kg
Max speed: 261km/h
Cruising speed: 232km/h
Hovering ceiling, OGE: 2600m
Range with max fuel: 748km
Payload: 3630kg

HH-3E
Engines: 2 x General Electric CT58-GE-5, 1500 shp each
MTOW: 22,500 lb
Max ldg wt: 19,500 lb
Length: 57 ft 3 in
Rotor dia: 62 ft
Speed: 162 mph
Ceiling: 11,100 ft
Range: 465 miles
Pax cap: 30
Crew: 2

HH 3F

SH-3A Sea King
Engines: 2 x General Electric T58-GE-8B turboshaft, 1,250 shp
Main rotor dia: 62 ft (18.9m)
No of blades: 5
Length: 72 ft 8 in (22.15 m)
Main rotor disc area: 3019 sq.ft. (280.5sq.m)
Gross weight: 20,500 lb (9300 kg)
Cruise speed: 136 mph (219 kph)
Max range: 625 miles (1,005 km)
Crew: 4

SH-3D
Powerplant: two 1,400 shp (1044 kW) General Electric T58 10 turboshafts
Armament: external hard-points for 381 kg (840 lb) / 2 Mk.46 torpedos
Maximum speed 267 km/h (166 mph)
Range max fuel and 10% res 1005 km (625 miles)
Empty weight 5382kg (11,865 lb)
Maximum take off weight 9752 kg (21,500 lb)
Main rotor diameter: 18.9 m (62 ft 0 in)
Fuselage length: 16.69 m (54 ft 9 in)
Height 5.13 m (16 ft 10 in)
Main rotor disc area 280.5sq.m (3,019.1 sq ft)
Max external cargo lift: 9,000 lb
Max altitude: 14,700ft
Maximum gross weight 21,000 lb
Fuel capacity: Forward tank 1,314 lt, centre tank 530 lt, rear tank 1,336 lt. Total capacity 3,180 lt
Oil capacity 26.5 litres.

Agusta Sikorsky SH 3D
Rotor dia: 62 ft 0 in (18.9 m)
Cruise speed: 136 mph (219 km/h)

Westland Sea King (RAAF)
Engines Two Rolls Royce Gnome gas turbines
Length 22.15 m / 72.671 ft
Height 5.13 m / 16.831 ft
Width 18.9 m / 62.008 ft
Weight 9525 kg / 21,000 lb
Speed 230 kph
Range 925 km / 574.768 mi
Crew 4 (2 Pilots, Tactical Coordinator, Air-crewman)
Weapon One 7.62 machine gun

Westland Sea King
Powerplant: two 1,660shp (1238 kW) Rolls Royce Gnome H.1400 1 turboshafts
Cruising speed at max¬imum weight: 208 km/h (129 mph)
Range on standard fuel: 1230 km (764 miles)
Max speed: 132 kt
Empty weight 6201 kg (13 672 lb)
Gross weight: 21,500 lb (9,751 kg)
ROC: 615 m/min
Fuel cap (aux): 3640 lt (910 lt)
No blades: 5
Main rotor diameter 18,9 m (62 ft 0 in)
No of blades: Main – 5, Tail – 6
Fuselage length 17.01 m (55 ft 9.75 in)
Height 5.13 m (16 ft 10 in)
Main rotor disc area 280.5 sq.m (3,019,1 sq ft)
Armament: four Mk 46 torpedoes or Mk.11 depth charges
HIGE: 5600 ft
HOGE: 3500 ft
Service ceiling: 10,000 ft
Crew: 4
Pax: 28

Westland Commando
Fuselage length: 56 ft (17m)

Westland HAS.1

Westland Sea King HAS Mk.5
Engine: 2 x Rolls-Royce Gnome H.1400-1 turboshaft, 1238kW
Main rotor diameter: 18.9m
Length with rotors turning: 22.15m
Height: 4.72m
Max take-off weight: 9525kg
Loaded weight: 6202kg
Cruising speed: 208km/h
Range: 1230km
Armament: 4 x Mk.46 torpedos or 4 x Mk.11 depth charges

Westland HAS.6

Westland HC.4

Westland HAEW Mk.2
Main rotor diameter: 18.90m
Fuselage length: 16.69m
Height: 4.74m
Max take-off weight: 9500kg
Cruising speed: 208km/h
Hovering ceiling, OGE: 2500m
Range with max fuel: 1200km
Duration of patrol: 4-4.5h
Crew: 4

Sikorsky CH 124 Sea King
Engines: 2 x Rolls Royce Gnome H.1400, 1479 shp
Length: 54.757 ft / 16.69 m
Height: 15.912 ft / 4.85 m
Rotor diameter: 62.008 ft / 18.9 m
Max take off weight: 21501.0 lb / 9751.0 kg
Weight empty: 15476.9 lb / 7019.0 kg
Max. speed: 124 kt / 230 km/h
Cruising speed: 114 kt / 211 km/h
Service ceiling: 10007 ft / 3050 m
Maximum range: 880 nm / 1630 km
Range: 880 nm / 1630 km
Range (max. weight): 599 nm / 1110 km
Crew: 2
Payload: 27 Pax / 2720 Kg
Armament: 2720 Kg