In late 1971 the Army Air Mobility Research and Development Laboratory awarded Sikorsky a contract for the development of a single-engine research helicopter prototype designed specifically to flight test the company’s Advancing Blade Concept (ABC) rotor system. This new system consisted of two rigid, contra-rotating rotors which made use of the aerodynamic lift of the advancing blades. The XH-59A’s ABC system consisted of two three-bladed, coaxial, contra-rotating rigid rotors, both of which were driven by the craft’s single 1825shp PT6T-3 Turbo Twin Pac engine. During high-speed flight only the advancing blades of each rotor generated lift; this off-loaded the retreating blades and thereby eliminated the aerodynamic restrictions caused by blade-stall and the high mach number effect of the advancing blade tip. This, in turn, produced greater stability and manoeuvrability while eliminating the need for either a supplementary lift-generating wing or an anti-torque tail rotor. The XH-59A’s streamlined fuselage more closely resembled that of a conventional airplane than a helicopter, having a cantilever tail unit with twin endplate rudders, side-by-side seating for the two crewmen, and fully retractable tricycle landing gear.
First using scale models for wind tunnel tests at the Ames NASA research center, and then the real aircraft, the resultant Model S-69, which was allotted the military designation XH-59A and the serial number 73-21942 (c/n 69-002), made its first flight on 26 July 1973. This was extensively flight tested as a pure helicopter and, with auxiliary propulsion, flown at speeds in excess of 480 km/h / 300 kt and altitudes of more than 25,000 ft. This prototype was lost in an accident a month after the first flight.
The first prototype was written off and the cockpit was used in the Paris air-show to demonstrate a sighting system for LHX.
Following an enquiry, design modifications were requested, plus improvements to the control system. Tests were resumed in July 1975 with the second prototype incorporating several significant control system modifications. This second machine (73-21941 c/n 69-001) flew for the first time in 1975, completing the pure helicopter portion of the program, and in 1977 was converted into a compound rotorcraft through the installation of two 1350kg J60-P-3A turbojet engines. The modified machine was jointly evaluated by the Army, Navy, and NASA at NASA’s Moffet Field, California beginning in 1978, and was later able to reach and maintain speeds in excess of 515kph in level flight.
In 1982 the plan was to develop this aircraft into a new XH-59B configuration with advanced rotors, new power plant, and a ducted pusher propeller at the tail. This approach was seen as a possible solution to the Army’s search for a new light attack helicopter (LHX), and further funding was recommended. The S-69/XH-59 program was abandoned, however to pursue the XH15.
The existing XH-59A aircraft was officially transferred to the Army museum at Fort Rucker Alabama following the 1981 end of joint Army/Navy participation in the tri-partite flight test program.
In 1964, Sikorsky submitted the S-66 project to the US Army for the AAFSS specification 1965/6, calling for an aircraft with a maximum speed of approximately 418km/h and ten minutes’ hovering capability.
The S-66 had a Rotorprop tail rotor which could rotate its axis through 90° to act both as a conventional anti-torque rotor in horizontal flight and as a pusher propeller, thereby transforming the S-66 into a compound aircraft in cruising flight. When the AH-56A failed to live up to expectations, Sikorsky first offered an intermediate aircraft, consisting of an armed version of the S-61, then designed a simplified AAFSS using the maximum number of components from the S-61. The S-67 used the S-61 rotor system and engines with new gunship fuselage and 27’4″ wings. The result was the S-67 Blackhawk which appeared in 1970.
The Blackhawk looked like a helicopter with conventional rotors (those of the S-61) and had the now typical lines and features of a combat helicopter: two stub wings with a 8.33m span and an all-moving tail plane. The main-wheels were retractable, while the tailwheel was not. There were speed brakes on the wing trailing edges, which could be used both as airbrakes and to improve manoeuvrability. In addition the main rotor blade tips were modified and given a sweep-back of 20°, to reduce vibration, stall speed and noise. Power was by two 1119kW General Electric T58-GE-5 engines.
First flown on Aug 27, 1970, the Blackhawk was put through a long series of tests from 1970 to 1974 and established an E-1 class world speed record on 14 December 1970 by flying at 348.971km/h / 216.84 mph over 3km (pilot Byron Graham), beating this on 19 December with a new record of 335.485km/h / 220.89 mph over a 15/25km circuit (pilot Kurt Cannon). In the final stages of testing, the S-67 was fitted with night vision systems, a TAT-140 turret with a 30mm cannon and an insulated and soundproof compartment for troop transport. The S-67 was also designed to carry an armament of 16 TOW antitank missiles, 2.75 in rockets or Sidewinder air-to-air missiles.
The Blackhawk demonstrated excellent manoeuvrability, weapon carrying capacity and versatility. At the end of the test cycle, the US Army asked for the aircraft to be modified by substituting a ducted fan for the tail unit, and in this configuration it reached a speed of 370km/h in a test dive in 1974.
Its development was abandoned after it was destroyed in a crash at 1974 Farnborough air show.
Sikorsky S-67 Engines: 2 x General Electric T58-GE-5 turboshaft, 1500 shp / 1119kW Rotor Span: 18.90 m / 62’0″ five-blade Wingspan: 8.33m / 27’4″ Length: 22.6 m / 74’4″ Height: 4.57 m Empty weight: 5681 kg Max weight: 11010 kg Max Speed: 311 km/h / 193 mph Rate of climb: 12.1m/s Service Ceiling: 5180 m / 17,000′ Range: 354 km Crew: 2
On the basis of the S-61R project for the Marines, the American company proposed the S-65A with a completely redesigned, large-capacity fuselage, capable of transporting 37 equipped troops or 24 stretchers with 4 medical attendants.
The S-65A fuselage is a scaled-up version of that used on the S-61R. The fuselage is a conventional semi-monocoque structure of aluminium, steel and titanium, a folding tail pylon, and with a horizontal stabiliser on the starboard side of the tail rotor pylon. The rotor system and transmission are generally similar the S-64A Skycrane, but the main rotor head is of titanium and steel, and has folding blades. The flat-bottomed body is watertight and has similar sponsons amidships in which are housed fuel tanks and the main undercarriage members when retracted. The fully castoring nosewheel is also fully retractable. The retractable tricycle type landing gear, has twin wheels on each unit. Main units retract into rear of sponsons on each side of fuselage. Mainwheels and nosewheels have tyres size 25.65 x 8.50-10, pressure 6.55 bars. Basic empty weight is reduced by the use of titanium in the rotor head. The S-65A carries a crew of 3 and can airlift 38 troops and their equipment, 24 casualty litters and 4 medical attendants, or some 3630kg of cargo within the fuselage. The interior of the CH-53 is fitted with rollers for easy movement of cargo. A let-down rear ramp provides access for such military loads as 2 jeeps, a Hawk missiles, or a 105mm howitzer and its carriage. A slung load of some 5900kg can be lifted on an under-fuselage hook.
Power is normally two 2,850 shp / 2,125kW General Electric T64-GE-6 turboshaft engines, mounted in pod on each side of main rotor pylon. The CH-53A can also utilise, without airframe modification, the T64-GE-1 engine of 2,297kW or the later T64-GE-16 (mod) engine of 2,561.5kW. Two self-sealing bladder fuel tanks, each with capacity of 1,192 litres, housed in forward part of sponsons. Total fuel capacity 2,384 litres.
With a crew of three, the main cabin accommodates 37 combat-equipped troops on inward-facing seats. Provision for carrying 24 stretchers and four attendants. Roller-skid track combination in floor for handling heavy freight. Door on starboard side of cabin at front. Rear-loading ramp.
Sikorsky S-65A
The first flying on 14 October 1964, the YCH-53A Sea Stallion demonstrated ruggedness of design by flying with three of six main rotor blades removed, and also performed a barrel-roll. Two YCH-53A were built, 151613 and 151614. One commercial demonstrator was later sold to NASA.
The US Navy, which is responsible for acquisitions for the Marines, in August 1962, announced that the S-65A had been selected as a new ship-borne heavy assault transport for the U.S. Marine Corps, with the military title CH-53A Sea Stallion.
The first Sea Stallion flew on 14 October 1965 powered by two 2125kW General Electric T64-GE6 engines, and delivery of the first 106 helicopters began in September 1966. The aircraft were assigned to Marine Squadron HMH-463 in Vietnam in January 1967. At that period, it was the largest helicopter in the Western world.
On 17 February 1968, a CH-53A with modified T64 engines took off with a gross weight of 23540kg and a 9925kg payload, establishing an unofficial record. On 23 October of the following year a Sea Stallion demonstrated surprising manoeuvrability when it performed a series of loops and rolls with Lt.-Col. Robert Guay of the Marines and Sikorsky test pilot Byron Graham at the controls, carrying a gross weight of 12250kg. During these manoeuvres, the helicopter supported from -0.2 to 2.8g.
Delivery of the first of one hundred and six production CH-53A’s began in September 1966. Since January 1967 the Sea Stallion has been serving with Marine Squadron HMH-463 in Vietnam, and by that summer some thirty Sea Stallions had been delivered. Standard powerplant is the T64-GE-6 shaft turbine, though the 3080shp T64-GE-1, 3435shp T64-GE-16 or GE T64-GE-3/-6/-12 may be fitted. One CH-53A with standard engines has been flown at a gross weight of 20865kg, of which 9072kg was payload. One hundred ad thirty-nine were built; 151686 to 151701, 152392 to 152415, 153274 to 153313, 153705 to 153739, 154863 to 154888, and 63-13693 to 13694, of which 15 transferred to USN as RH-53A and 9 to USAF, 66-30047, -30049, -30050, 67-30043 to 30046, -30048, and -30051. 152399 went to the FAA as NCH-53A and wore a civil license.
In September 1966, the USAF also ordered this big helicopter for its rescue service to assist space programmes and recover pilots from war zones. The eight HH-53B, 66-14428 to 14435, ordered for the USAF were known as “Super Jolly Green Giants” and fitted with in-flight refuelling probes, jettisonable auxiliary fuel tanks, rescue hoists and all-weather avionics. Flown for the first time on 15 March 1967. This version has 3080shp T64-GE-3 engines. It also has defensive machine gun positions fore and aft.
A batch of eleven ex-USMC, 66-14468 to 14478, went to the USAF in 1988 as TH-53A.
The HH-53B is employed by the Aerospace Rescue and Recovery Service of the U.S. Air Force, and delivery of an initial batch began in June 1967. Two of these aircraft were stationed at Cape Kennedy in connection with the Apollo manned spacecraft programme.
Parallel with the military variants, Sikorsky had under development a commercial model of the S-65A. This was currently envisaged with 3435shp T64 engines and an enlarged pressurised fuselage to seat 67 passengers.
Fifty-eight of the subsequent HH-53C variant with uprated turbines (3435shp each) were built from 1967. Used for space capsule recovery and combat SAR, they were similar to HH-53B, but with 3925hp T64-GE-7 engines and jettisonable fuel tanks.
The CH-53C Super Jolly was as the HH-53C, but in transport roles. Twenty were built, 68-10922 to 10933, and 70-1625 to 1632.
After having used the early production aircraft, the US Marine Corps also asked for more powerful engines to be installed, and the result was the CH-53D, introduced in March 1969, with 3925shp / 2927kW T64-GE-413 engines. In this version, the tail and rotor could be folded back automatically, and a high density cabin layout was available to accommodate 64 troops, equivalent to the S-65C export version. All but the first 34 had fittings to operate as minesweepers. A total of 265 CH-53As and Ds were built for the Marines; the last left the factory on 31 January 1972.
Of the early versions, all are transports (139 CH 53As and 126 of the more powerful CH 53D, all for the US Marines) except for 15 CH-53A, including 152392-152398, transferred to the US Navy as RH 53A Sea Stallion minesweeping machines with T64-GE-413 engines in 1971.
Last CH-53D (the 26th built) was delivered on 31 January 1972. All but the first 34 CH-53s were provided with hardpoints for supporting towing equipment and transferring tow loads to the airframe, so that the US Marine Corps could utilise the aircraft as airborne minesweepers, giving an assault commander the capability of clearing enemy mines from harbours and off beaches without having to wait for surface minesweepers.
Tow kits installed in the 15 CH-53Ds operated by the US Navy Squadron HM-12 included automatic flight control system interconnections to provide automatic cable yaw angle retention and aircraft attitude and heading hold. Rearview mirrors are fitted for pilot and co-pilot; tow cable tension and yaw angle indicator; automatic emergency cable release; towboom and hook system with 6,803kg load capacity when cable was locked to internal towboom. A dam to prevent cabin flooding in emergency water landing with lower ramp open; dual hydraulically powered cable winches; racks and cradles for stowage of minesweeping equipment; auxiliary fuel tanks in cabin to increase endurance.
HH-53B and HH-53C SAR variants were built for the US Air Force, the former equipped to a standard similar to that of the HH-3E and powered by 2297kW T64-GE-3 engines. It was first flown on 15 March 1967. Sponson bracing struts allowed the HH-53B to carry 2460-I drop-tanks. More powerful 3,925kW T64-GE-7 engines powered the improved HH-53C, the same powerplant being installed in the CH-53G produced for the German army. Two S-65Oe rescue helicopters were delivered to the Austrian air force in 1970.
S-65C-3 were sold to the Israel Defense Force/Air Force.
A specialised minesweeping version, the RH-53D, was first flown on 27 October 1972 with drop-tanks and in-flight refuelling probes. To complete its experiments with the RH-3A, the US Navy borrowed nine CH-53Ds from the Marines, fitted with devices for the detection, sweeping and neutralization of all types of mines. This variant was designated RH-53D, and 30 were produced for the US Navy and six for the Iranian Navy in 1978. The RH-53 has 1900 liter supplementary fuel tanks, a 270kg hoist and 11340kg cargo hook. Minesweeping equipment is towed behind the helicopter on a trapeze. Towing equipment was installed from the 34th production aircraft onwards. Once brought to the surface, mines are detonated using two door-mounted machine-guns. Though a dedicated minesweeper, the RH-53D also has a transport role. At the beginning of 1973, these helicopters were used by US Navy Task Force 78 for Operation Endsweep, to free the North Vietnamese ports of mines. Some ships used for tests were designated as NRH-53D.
Eight RH-53Ds were used to fly into Iran during Operation Eagle Claw to rescue the hostages held by Iran in 1980; seven were destroyed. RH-53Ds were deployed to the Persian Gulf for minesweeping operations in 1987, and in 1991 for Desert Storm.
Two VH-53D Sea Stallion were USMC staff transport.
The Sea Stallion also aroused some interest in other countries where there was a requirement for a helicopter for troop transport. Thus the S-65A was also ordered by Germany. Two pattern aircraft were built in the US and 110 were built under license by VFW-Fokker as the CH-53G with T64-GE-7 engines. Another eight aircraft, modified for use in hot/high conditions, were exported to Israel.
Work began in 1971 on an enlarged version with a lengthened fuselage, a new rotor system and three 3266kW T64-GE-416 engines. The US Navy contract covering two prototypes and subsequent flight test was awarded in 1973, and the S-80 / YCH-53E prototype (71-59121) flew for the first time on 1 March 1974. During tests it was hovered at 50′ at a gross weight of 71,700 lb on 10 August 1974, carrying an external load of 17.8 tons, the heaviest gross weight ever flown and heaviest payload ever lifted by a helicopter in the western world. With the three engines each of 4,380 shp (3266 kW) it was the most powerful helicopter ever built outside the Soviet Union. First flight of first production prototype was on 8 December 1975, and the second production prototype in March 1976. Fitted with in-flight refueling, two YCH-53E Super Stallion prototypes were built.
Sikorsky CH-53E USMC
This is a much modified version with three 4380shp General Electric T64-GE-416 engines and strengthened transmission to withstand the increase in power. The fuselage is about 2m longer than that of the CH-53D and the tail pylon is canted to port. The main rotor has also been improved and has seven composite blades (its predecessor had six light alloy ones) of increased diameter. Thirty-three CH-53Es were initially ordered by the Marines and 16 by the US Navy.
The first production CH 53E flew on 13 December 1980, and the first delivery of a CH-53E took place on 16 June 1981 at Stratford, Con. This CH-53E (the sixth of the initial production lot, the preceding five serving as acceptance test procedures, avionics testing, maintenance and pilot training programs) entered service with HMH-464 Marine Aircraft Group 26. It was the first of 20 contracted.
By mid 1983 more than 40 had been delivered out of 72 ordered. Specifically designed for USN/USMC, they carried 55 troops and two 650-gallon fuel tanks on sponsons, A total of 103 CH-53 were built.
JCH-53E and NMH-53E were designations for test aircraft.
S-80/CH-53E
Full-scale development of Helicopter Night Vision System (HNVS) for CH-53E began June 1986, in co-operation with Northrop Electro-Mechanical Division; HNVS includes Lockheed Martin Pilot Night Vision System (PNVS) and Honeywell Integrated Helmet and Display Sighting System (IHADSS) from Bell AH-1S surrogate trainer; HNVS will allow low-level operations in night and adverse weather; HNVS ground testing began 1988; operational evaluation began August 1989. Smaller-scale capability authorised 1993, with contract to EER Systems for installation of Hughes AN/AAQ-16B FLIR, Teledyne Ryan Electronics AN/APN-217 Doppler and Rockwell Collins GPS 3A; total 24 upgrades initially authorised; subsequent contracts for 99 HNVS with work scheduled for completion in May 1999. USMC has also evaluated engine-suppression system as means of reducing IR signature, and new multiple cargo hook concept.
The CH-53E can accommodate 55 fully equipped combat troops, wheeled vehicles, and palletised cargo, and has a 16-ton heavy-lift capability. In-flight refuelling plus a folding rotor and tail boom for shipboard stowage are also provided.
The first CH-53E Super Stallion delivery to the US Marine Corps took place on 16 June 1981. Since 1982 Sikorsky has been developing the MH-53E mine countermeasures variant. It incorporates major equipment changes and has much enlarged sponsons to carry an additional 3785 litres of fuel. Six were delivered in 1986. June 1987 marked six years in service for the CH-53E Super Stallion.
In addition Sikorsky is de¬veloping the derived MH 53E as a de¬finitive MCM (mine countermeasures) helicopter, with very comprehensive minesweeping gear using all existing or planned MCM devices. Enormously enlarged side sponsons accommodate an extra 3785 litres (833 Imp gal) of fuel, for extended sweeping missions with the engines at sustained high power, The MH 53E will also be used in the vertrep (vertical replenishment of ships) role, and has been made com¬patible with the cargo hold of the Lock¬heed C 5 Galaxy in order that it can be deployed rapidly anywhere in the world. Bureau number 162497 was the first true production MH53E. The first delivery (of 35 built) of an MH-53E Sea Dragon airborne mine counter¬measures (AMCM) helicopter to a US Navy fleet squadron took place in April 1987. Based on the triple-turbine CH-53E airframe, the MH-53E has extra-large sponsons made of composite material, each holding 1,600gal of fuel allowing a 4hr minesweeping mission. To accomplish its task the Sea Dragon tows mechanical, acoustic, and magnetic hydrofoil sweeping gear through the water. A dual digital automatic flight control system allows automatic approach to, and departure from, a coupled hover, with tow cable tension and skew-angle hold functions. In-flight refueling capability aids rapid long-range deployment, while rotor-blade and tail-boom folding ensures compatibility with all US Navy AMCM ships.
Sikorsky MH-53E Towing minesweeper sled
Delivery effected 1994 of MH-53E retrofitted with upgraded avionics package by EER Systems, comprising two 15.2 cm (6 in) horizontal situation display colour screens, Fairchild mission data loader and Rockwell Collins GPS 3A; upgrade of entire MH-53E fleet planned but may be reduced to around 30 as result of defence budget trimming. One MH-53E to West Palm Beach, Florida, for installation of T64-GE-419 engines, late 1993. Trials during 1994 verified performance gains, including recovery and flyaway capability in event of engine failure during hover; retrofit of entire MH-53E fleet underway.
First flight of preproduction MH-53E, 1 September 1983; first delivery to US Navy 26 June 1986; in operational service with HM-14 at Norfolk, Virginia, 1 April 1987; first carrier deployment by HM-15 on board USS Tripoli, 9 December 1989.
Delivery effected 1994 of MH-53E retrofitted with upgraded avionics package by EER Systems, comprising two 15.2 cm (6 in) horizontal situation display colour screens, Fairchild mission data loader and Rockwell Collins GPS 3A; upgrade of entire MH-53E fleet planned but may be reduced to around 30 as result of defence budget trimming. One MH-53E to West Palm Beach, Florida, for installation of T64-GE-419 engines, late 1993. Trials during 1994 verified performance gains, including recovery and flyaway capability in event of engine failure during hover; retrofit of entire MH-53E fleet underway.
Export versions of the CH-53E and MH-53E were available as the S-80E and S-80M respectively.
Some CH-53C and HH-53B helicopters remained unmodified until the late 1980s, when they became MH-53Js. MH-53H and MH-53J Pave Low IIs were involved in the US invasion of Panama. Air Force special operations HH-53Hs and MH-53Js are rebuilds of HH-53B/Cs.
The 1975 HH-53H Super Jolly was a USAF 24-hour, all-weather SAR in the PAVE LOW program. One prototype was completed and eight conversions of HH-53C in 1979.
The 1981 MH-53J PAVE LOW IIIE were for heavy-lift, all-weather, long-range, undetected penetration. They were the largest and most powerful helicopter in USAF at the time, featuring PAVE low-level terrain-avoidance radar and forward-looking infrared sensors (FLIR), along with a projected map display, enabled pilot to follow land contours and avoid obstacles.
Sikorsky MH-53
Six Sikorsky VH-53F Super Stallion were ordered for the USAF but with US Navy bureau numbers (159123 / 159128) for VIP transport by the 89th Military Airlift Wing. These were cancelled before deliveries could take place.
Production: 151613-151614 (2) YCH53A 151686-154884 (128) CH53A 156654-157931 (126) CH53D 158682-158761 (30) RH53D 161179-165651 (177) CH53E 161395-164864 (48) MH53E 168778-168782 (5) YCH53K (1 GTV, 5 EDM) Bureau number 161395 was later converted from a CH53E to MH53E
Variants:
YCH-53A Winner of the HH(X) competition, two prototype CH-53As were completed for US Navy evaluation, by March 1966; first flight made by second aircraft (BuNo. 151614) on 14 October 1964, powered by two T64-GE-6 turboshafts
CH-53A Initial version powered by two General Electric T64 turboshaft engines and has a watertight hull for US Marine Corps, deliveries commencing in September 1965. A full-size rear opening, with built-in ramp, permits easy loading and unloading, with the aid of a special hydraulically operated internal cargo loading system and floor rollers. Accelerated deployment to South East Asia made after improvements to engine intake filters, defensive armament, crew armour and external lifting capability; selected T64-GE-1 engines retrofitted for extended running at maximum power output when necessary; fitted with hardpoints for towing mine-sweeping gear from 34th aircraft onwards; used by USAF for crew training and later for covert operations in Vietnam and Laos (seven aircraft borrowed from and returned to Navy); 139 built
RH-53A 15 dedicated mine-counter-measures versions delivered to the Navy via the Marine Corps; re-engined with T64-GE-413 turboshafts; rectangular frame mounted on rear ramp to tow mine clearing sled and rear view mirrors fitted on either side of the nose; used to clear North Vietnamese mines during Operation Endsweep in 1973; RH-53As replaced by RH-53Ds in Navy service and aircraft returned to Marines
TH-53A Former USMC CH-53As used by USAF from 1989 onwards to train MH-53 crews at Kirtland AFB, NM; at least three aircraft in use, stripped of most equipment and camouflaged
HH-53B Eight aircraft similar to CH-53A but delivered to USAF Aerospace Rescue and Recovery Service to supplement HH-3s in South East Asia. The first of these flew 15 March 1967, powered by 2,297kW T64-GE-3 turboshaft engines. Refuelling probe relocated to starboard side of nose, pylons fitted to allow carriage of external fuel tanks; armed with three pintle-mounted GAU-2A/B 7.62mm Miniguns and powered by T64-GE-3s, later replaced by T64-GE-7s; quickly supplemented by HH-53Cs and re-assigned to CONUS, the last four HH-53Bs were modified to MH-53J standard in the late 1980s
CH-53C 22 aircraft built for heavy-lift duties with the USAF; fitted with sponsons and external tanks as developed for HH-53C, it was similar in most respects to this version but lacked a refuelling probe; replaced CH-53As on loan from USMC for covert operations in Laos; later operated by TAC and USAFE; seven surviving CH-53Cs brought up to MH-53J standard in late 1980s
HH-53C Refined version of HH-53B, with 2,927kW T64-GE-7 engines. 44 were built for USAF ARRS for combat rescue; dubbed ‘Super Jolly Green Giant’; dispensed with bracing struts fore the external pylons, and included additional crew armour, and better radio fit to facilitate operations with HC-130 tankers. Auxiliary jettisonable fuel tanks each of 1,703 litres capacity on new cantilever mounts. Flight refuelling probe, and rescue hoist with 76m of cable. External cargo hook of 9,070kg capacity. RHAW and IR jamming systems introduced as a result of experience in North Vietnam during 1972; HH-53Cs used in support of Apollo space missions for emergency capsule rescue; HH-53Cs remained in USAF service until late 1980s when all were converted to MH-53J standard First HH-53C was delivered to the USAF 30 August 1968. A total of 72 HH-53B/Cs was built.
S-65C Commercial intercity helicopter proposal based on military CH-53.
S-65C-2 / S-65O Export version of CH-53C, two of which were ordered in 1969 and delivered to the Austrian air force in 1970; later retired from use due to operating costs and passed on to Israel in 1981. Used for rescue duties in the Alps, they have the same rescue hoist as the HH-53B/C, fittings for auxiliary fuel tanks and accommodation for 38 passengers.
S-65-C3 Only other export version of H-53, delivered to Israel from 1969; corresponding to HH-53C, 33 aircraft supplemented by two additional S-65s from Austria in 1981; surviving aircraft upgraded by IAI subsidiary MATA Helicopters
CH-53D Improved CH-53A for US Marine Corps, the first of which was delivered on 3 March 1969. Two T64-GE-413 engines, each with a maximum rating of 2,927kW. A total of 55 troops can be carried in a high-density arrangement. An integral cargo handling system makes it possible for one man to load or unload 1 ton of palletised cargo a minute. Main rotor and tail pylon fold automatically for carrier stowage, first flown on 27 January 1969; 124 built.
RH-53D First flown 27 October 1972; 30 aircraft (named Sea Stallion) specifically developed for anti-mine warfare in the light of positive experience with RH-53A; fitted with an initial powerplant of two T64-GE-415s, RH-53D also differs from RH-53A by inclusion of refuelling probe, automatic flight control system, more powerful cargo hook, and rescue winch; armed with two’swivel-mounted 12.7mm machine-guns; six delivered to Imperial Iranian navy before the fall of the Shah
VH-53D Two CH-53Ds delivered to USMC for VIP transport
YCH-53E Three-engined development of the CH-53D.\
CH-53E Super Stallion Heavy transport and amphibious assault helicopter (first flown March 1974)
MH-53E Sea Dragon / S-80 Airborne mine countermeasures helicopter able to tow through water hydrofoil sledge carrying mechanical, acoustic and magnetic sensors; nearly 3,785 litres (1,000 US gallons; 833 Imp gallons) extra fuel carried in enlarged sponsons made of composites; improved hydraulic and electrical systems; minefield, navigation and automatic flight control system with automatic towing and approach and departure from hover modes.
CH-53K Cargo, USN & USMC
CH-53G Version of the CH-53 for the German armed forces order for 135 examples, later reduced to 110, with T64-GE-7 engines. A total of 112 were produced, the first of two built by Sikorsky being delivered 31 March 1969. The next 20 were assembled in Germany by VFW-Fokker from US-built components, then progressively increasing indigenous sources. Prime contractor in Germany was VFW-Fokker, whose first CH-53G flew 11 October 1971, entered service in-1973. Deliveries completed in 1975.
YHH-53H First aircraft to be fitted with ‘Pave Low I’, in trials for a projected night/ all-weather combat rescue/infiltration mission; fitted with early low-light TV system which proved inadequate, though the first successful night rescue was made with an improved system in December 1972, in Laos; aircraft later modified to ‘Pave Low II’ standard, with external sponsons and tanks
HH-53H Eight HH-53Cs and YHH-53H modified to definitive ‘Pave Low III’ standard; delivered between 1979 and 1980 and fitted with FLIR, TF radar, INS, computer generated moving map display, RHAW and chaff/flare dispensers. Eight converted to MH-53J Pave Low III.
MH-53H Redesignation and modification of HH-53H under the Constant Green programme; all ‘Pave Low III’ aircraft were modified to MH-53J standard
MH-53J Pave Low III Enhanced US Air Force upgrade of Special Operations Forces combat rescue and recovery fleet; 31 HH-53Bs, HH-53Cs and CH-53Cs converted at NAS Pensacola, Florida, beginning 1986, to MH-53J Pave Low III Enhanced; similar to 11 HH-53H Pave Low III produced earlier, eight survivors of which also converted to MH-53Js; programme completed in 1990. Modifications include Texas Instruments AN/AAQ-10 nose-mounted FLIR, inertial navigation, Doppler radar, computer-projected map display, Navstar GPS, Texas Instruments AN/APQ-158 terrain-following/avoidance radar in offset nose radome, chaff/flare dispensers, Loral AN/ALQ-157 IR jammer on each outrigger pylon, 454kg of extra titanium armour plating and Collins AN/AIC-3 intercom; armament includes three 7.62mm or 12.7mm machine guns firing through windows on each side and from open rear ramp. Power plant is two 3,266kW General Electric T64-GE-415 turboshafts; maximum T-O weight increased from 19050 to 22,680kg. Further upgrades planned to improve combat effectiveness and service life. Those modified from HH-53Bs retain braced external tank pylons of first Super Jollys.
MH-53M Pave Low IV Internal upgrade featuring new avionics and defence aids, including an integrated AP-102A weapon systems computer to speed up target acquisition. All 39 existing MH-53J Pave Low III’s are expected to be converted.
S-80E Export version of CH-53E.
S-80M Export version of MH-53E; total of 11 delivered to Japan for Japanese Maritime Self-Defence Force (JMSDF).
Yasur 2000 Upgrade of 30 Israeli Air Force CH-53Ds by IAI. Improved avionics and structural changes to extend service life. Other modifications include internal auxiliary fuel tanks, flight refuelling boom, rescue hoist, crashworthy seats and cockpit armour.
Detailed description refers to CH-53E, but applicable also to MH-53E and S-80 export versions, except where indicated.
COSTS: US$24.36 million (1992) projected average unit cost.
DESIGN FEATURES: Fully articulated seven-blade main rotor; blade twist 14°; hydraulic powered blade folding for main rotor; tail pylon folds hydraulically to starboard; four composite-blades tail rotor on pylon canted 20° to port to derive some lift from tail rotor and extend CG range; cranked, strut braced tailplane; rotor brake standard; fuselage stressed for 20 g vertical and 10 g lateral crash loads.
FLYING CONTROLS: Fully powered, with autostabilisation and autopilot. See also Current Versions and Avionics.
STRUCTURE: Fuselage has watertight primary structure of light alloy, steel and titanium; glass fibre/epoxy cockpit section; extensive use of Kevlar in transmission fairing and engine cowlings; main rotor blades have titanium spar, Nomex honeycomb core and glass fibre/epoxy composites skin; titanium and steel rotor head; Sikorsky Inflight Blade Inspection Method (IBIM) sensors detect blade spar cracks occurring in service; tail rotor of aluminium; pylon and tailplane of Kevlar composites.
LANDING GEAR: Retractable tricycle type, with twin wheels on each unit. Main units retract into rear of sponsons on each side of fuselage. Fully castoring nosewheels.
POWER PLANT: Three General Electric T64-GE-416 turboshafts, each with a maximum rating of 3,266kW for 10 minutes, intermediate rating of 3,091kW for 30 minutes and maximum continuous power rating of 2,756kW. Transmission rated at 10,067kW for take-off. Retrofit underway with 3,539kW T64-GE-419 turboshafts.
Self-sealing bladder fuel cell in forward part of each sponson, each with capacity of 1,192 litres. Additional two-cell unit, with capacity of 1,465 litres, brings total standard internal capacity to 3,849 litres. (Total internal capacity of MH-53E is 12,113 litres)
Optional drop tank outboard of each sponson of CH-53E, total capacity 4,921 litres. (MH-53E can carry seven internal range extension tanks, total capacity 7,949 litres) Forward extendable probe for in-flight refuelling. Alternatively, aircraft can refuel by hoisting hose from surface vessel while hovering.
ACCOMMODATION: Crew of three. Main cabin of CH-53E will accommodate up to 55 troops on folding canvas seats along walls and in centre of cabin or 24 litters. Door on forward starboard side of main cabin. Hydraulically operated rear-loading ramp. Typical freight loads include seven standard 1.02 x 1.22m pallets. Dual and single-point central hooks for slung cargo, capacity 16,330kg.
SYSTEMS: Hydraulic system, with four pumps, for collective, cyclic pitch/roll, yaw and feel augmentation flight control servo mechanisms; engine starters; Engine Air Particle Separators (EAPS); engine and hydraulic oil replenishment in flight; landing gear actuation; cargo winches; loading ramp; and blade and tail pylon folding. System pressure 207 bars, except for engine starter system which is rated at 276 bars. (Separate hydraulic system in MH-53E to power AMCM equipment.) Electrical system includes three 115V 400Hz 40 to 60kVA AC alternators, and two 28V 200A transformer-rectifiers for DC power. Solar APU.
AVIONICS: Flight: Hamilton Standard automatic flight control system, using two digital onboard computers and a four-axis autopilot. Retrofit test flown late 1993, comprising four Canadian Marconi CM A-2082 15.2cm square colour displays, tied with GPS, Doppler and AHRS; installation by Teledyne Ryan.
EQUIPMENT: MH-53E equipment includes Westinghouse AN/AQS-14 towed sonar, AN/AQS-17 mine neutralisation device, AN/ALQ-141 electronic sweep and Edo AN/ALQ-166 towed hydrofoil sled for detonating magnetic mines.
ARMAMENT: Window mount provisions for 7.62mm and 12.7mm weapons.
Specifications:
YCH-53A Sea Stallion Engines: two T64-GE-6 Max speed: 200+ mph No built: 2
S-65A Engines: two 3925hp T64-GE-413 turboshafts Rotor: 72’3″ Length: 67’2″ Max speed: 196 mph Range: 257 mi Crew: 3 Passenger capacity: 41
CH-53A Sea Stallion
CH-53D Engine: 2 x General Electric T64-GE-412 turboshaft, 2926kW / 3,925 shp Main rotor diameter: 22.02m Disc Area: 280.5 sq.m Fuselage length: 20.5m Height: 7.6m Max take-off weight: 19050kg Empty weight: 10650kg Max speed: 315km/h Cruising speed: 278km/h Range with payload: 2075km Rate of climb: 11m/s Service ceiling: 6220 m / 21,00 ft Internal (external) payload: 3710kg (9070kg) Accommodation: 37 troops or 24 stretchers
RH-53D / NRH-53D Sea Stallion Engines: two T64-GE-415
YCH-53E Super Stallion Engines: 3 x GE T64-GE-415, 4380hp turboshafts Main rotors: 7 Rotor dia: 24.08 m (79 ft 0 in) Length 73’9″ Max speed: 195 mph Cruise: 172 mph Range: 306 mi Ceiling: 18,500′
CH-53E Super Stallion Engine: 3 x General Electric T64 416 tur¬boshafts, 4380 shp (3266 kW) Rotor dia: 24.08 m (79 ft 0 in) Fuselage length: 22.3 m Length overall 30.19 m (99 ft 0.5 in) Height: 8,66 m (28 ft 5 in) No blades: 7 Main rotor disc area 455.38 sq.m (4,902.0 sq ft) Empty wt: 15071 kg (33,226 lb) MTOW: 33339 kg (73,500 lb) Payload: 14,515 kg Max speed: 170 kt Cruising speed at sea level 278 km/h (173mph) ROC: 840 m/min Fuel cap (aux): 4920 lt (4545 lt) Max range (unrefuelled): 2075 km Range: 56 mi with 16 tons external cargo Range: 575 mi with 10 tons external cargo HIGE: 11,550 ft HOGE: 9500 ft Ceiling: 5640 m / 18,500′ Crew: 3 Pax: 55
CH-53G Engines: 2 x T64-GE-7 Fuselage length: 67 ft 3 in (20.5m) Pax cap: 38 troops
HH-53 Jolly Green Giant Engines: 2 Fuselage length: 67 ft 3 in (20.5m) Pax cap: 38 troops
HH-53B Super Jolly Engines: 3080hp T64-GE-3 Seats: 6 No built: 8
MH-53E Sea Dragon Engine: 2 x GE T64-416, 4380hp Instant pwr: 3263 kW MTOW: 33,340 kg Payload: 16,587 kg Max speed: 170 kt Max range: 2035 km Ceiling: 27,900′ HIGE: 3520 ft HOGE: 2895 ft Crew: 3 Pax: 55
MH-53J PAVE LOW IIIE Engines: two 4330hp GE T64 Main rotor: 72’0″ Length: 92’0″ Max take-off weight: 46,000 lb Max speed: 165 mph Range: 630 mi Ceiling: 16,000′ Accommodation: 8
RH-53D Engines: 2 Fuselage length: 67 ft 3 in (20.5m) Pax cap: 38 troops
Before the S-60 was destroyed in April 1961, Sikorsky had already begun the S-64 Skycrane project. Sikorsky Aircraft produced the prototype (N325Y) of its S 64 Skycrane and this flew for the first time on 9 May 1962. The S 64 is a flying crane helicopter consisting of a basic skeletal to which can be attached large freight containers or people pods for short haul transportation. The S-64 retained the same basic rotor system as the S-60, and had a pair of 4050shp JFTD-12A shaft turbines mounted side-by-side on top of the fuselage boom, and had no fin area below the boom, and a 42,000-lb gross-weight. Ground clearance beneath this boom is 2.84m and the main wheel track is 6.02m, hence loads of considerable size can be fitted underneath the S-64. The six-blade, fully articulated main rotor and four-blade tail rotor. Steel driveshafts. Main gearbox below main rotor, intermediate gearbox at base of tail pylon. Tail gearbox at top of pylon. Main gearbox rated at 4,922kW on CH-54A. Two fuel tanks in fuselage, forward and aft of transmission, each with capacity of 1,664 litres. Total standard fuel capacity 3,328 litres. Provision for auxiliary fuel tank of 1,664 litres capacity, raising total fuel capacity to 4,992 litres.
Undercarriage is non-retractable tricycle type, with single wheel on each unit of CH-54A/S-64E, twin wheels on main units of S-64F. CH-54A/S-64E mainwheel tyres size 38.45 x 12.50-16, pressure 6.55 bars. S-64F mainwheel tyres size 25.65 x 8.50-10, pressure 6.90 bars. Nosewheels and tyres of all versions size 25.65 x 8.50-10, pressure 6.90 bars.
The pilot and co-pilot sit side by side at front of cabin. Aft-facing seat for third pilot at rear of cabin, with flying controls. The occupant of this third seat is able to take over control of the aircraft during loading and unloading. Two additional jump seats available in cabin.
A feature of this aircraft is that the landing gear can be lengthened and shortened hydraulically, so that the helicopter can ‘crouch’ on to its load, raise it off the ground and then, if desired, taxi with it to a more suitable take-off point. Two additional prototypes, N305Y and N306Y, were completed for evaluation by the Federal German forces. Re-registered D-9510 (early 1963) and D-9511, they were operated under the aegis of the former Weser Flugzeugbau.
After evaluation of the original prototype at Fort Benning, Georgia, the U.S. Army placed a pre-series order in June 1963 for six S-64A’s with the military designation YCH-54A and allotted the serial numbers 64-14202 through -14207. 64-4256 probably is a cancelled order. These aircraft were delivered to the Fort Benning-based 478th Aviation Company beginning in June 1964. Five of these were operated with the 478th Aviation Company supporting the U.S. Army’s 1st Cavalry Division in Vietnam.
Sikorsky CH-54 (US Army / KYNG)
This unit took four of the machines to Vietnam for a thorough field evaluation, upon the successful conclusion of which the Army placed orders for fifty-four CH-54A production aircraft, 66-18408-18413, 67-18414-18431, and 68-18432-18459. In 1965, a CH-54 at Ft. Bragg, N.C. established a world record lift of 90 passengers. Eighteen more CH-54A’s were ordered in 1966, and total orders stood at about sixty in 1968, later aircraft having uprated -4A engines of 4620shp each.
A military version, designated CH 54A, gained three international height records in 1965; those involving a 2,000 kg payload to a height of 28,743 ft (8,761 m) and a 1,000 kg payload to a height of 29,340 ft (8,943 m), were unbeaten in mid 1972.
Loads which can be lifted by the S-64A/CH-54A include trucks or palletised containers holding a field hospital unit, 48 casualty litters, 67 troops or 10382kg of cargo; one CH-54A in Vietnam has successfully lifted 87 troops.
Meanwhile a Sikorsky-owned S-64A and the sixth aircraft of the U.S. Army’s original order have been used to further the acceptance of the type for the civil market. During 1967, N325Y carried out tests on behalf of the Los Angeles Airport Department with the 23-seat Budd XB-1 Skylounge pod, designed to speed connection between the city’s airports and the city centre. The S-64’s cargo pod is a box 8.36 x 2.69 x 1.98m.
The larger CH-54B version with twin 4800shp T73-P-700 turbines and 2300kg more lifting power, went into service with the US Army in 1969; eventual thirty-seven CH-54Bs (serials 69-18462 through -18498). The -B model Tarhe differed from the earlier -A primarily in having more powerful engines, high-lift rotor blades, a modified main rotor gearbox and rotor head, a payload capacity increased by some 5000 pounds, and dual-wheeled main landing gear.
Sikorsky CH-54B 69-18464
Thirty-seven CH-54B were built; 69-18460-18484, 70-18485-18490, and 71-18491/18498. Twenty-two universal carrier pods, 27’5″ long and 8’10” wide, used by these aircraft were serialled separately (68-18578-18599).
Also under development was the S-64B/CH-54B, an enlarged three-turbine version designed to lift a 16329kg payload.
In addition to its use by civil operators on a variety of duties, 80 were ordered as CH 54A/B Tarhes by the US Army. The US Army bought 97 with deliveries between June, 1964 and 1972, and in Vietnam was used to retrieve 380 downed aircraft, saving $210 million. The Tarhe served in a heavy-lift role in Vietnam, with the 478th and the 291st Aviation Companies. The Tarhe can carry sling loads, vehicles or other items on a special platform, or a detachable military pod for 45 troops, 24 stretchers, or 20,000 lb (9,072 kg) of freight. The last one was retired in 1993.
On several occasions, CH-54s even served as makeshift bombers; they were among the few American aircraft in Southeast Asia that were capable of carrying, and dropping, the 10000 pound ‘daisy-cutter’ bombs used to create instant helicopter landing zones by flattening all vegetation (and most structures) within an area several hundred yards in diameter.
On 18 April 1969, two commercial Skycranes were delivered to Rowan Drilling Company Inc of Houston, Texas, for operation in support of oil exploration and drilling operations in Alaska.
During the late 1960s and early 1970s the Tarhe was gradually superseded in front-line service by the CH-47B and -C Chinook, and all surviving CH-54s were subsequently transferred to the Army Reserve and National Guard. Withdrawal from frontline units did not signal the Tarhe’s immediate demise, however, for as of early 1986 seventy-one -A model machines are shared among Georgia, Kansas, Mississippi, Nevada and Pennsylvania, while the twenty-six surviving -Bs serve in Alaska, Alabama and Connecticut.
When repairs were needed to the 11000kg statue atop Washington’s Capitol dome, it was lifted away and then returned by a SkyCrane.
Only 97 Tarhes were built for the United States Army between 1964 and 1972. Seven Army National Guard units were still equipped with it by the beginning of the 1990s. Progressively replaced by the CH-47D, the last unit to give up its CH-54s was D Company, 113th Aviation, of the Nevada Army National Guard, based in Reno, in 1993.
Sikorsky also offered the Skycrane to commercial operators. The models S-64E (civil version of the CH-54A) and S-64F (derived from the CH-54B) were produced, while plans for a triple turbine version were not realized.
In January 1972 Erickson Air-Crane Company of Marysville, California, purchased the first S-64E, for logging and other heavylift tasks. Erickson Air-Crane Co LLC purchased the Type Certificate and production rights for S-64 from Sikorsky on 1 February 1992, and can construct new examples to improved Erickson S-64 Aircrane standard. Erickson also developed modifications for ex-U.S. Army CH-54s to bring them up to Aircrane standard.
Versions:
S-64A Under this designation the first of three prototypes flew for the first time 9 May 1962 and was used by the US Army at Fort Benning, Georgia, for testing and demonstration. The second and third prototypes were evaluated by the German armed forces.
CH-54A Six ordered by US Army in 1963 to investigate the heavylift concept, with emphasis on increasing mobility in the battlefield. Delivery of five CH-54As (originally YCH-54As) to the US Army took place in late 1964 and early 1965. A sixth CH-54A remained at Stratford, with a company-owned S-64, for a programme leading toward a restricted FAA certification, which was awarded 30 July 1965. Further US Army orders followed.
CH-54B On 4 November 1968 Sikorsky announced that it had received a US Army contract to increase the payload capacity of the CH-54 from 10 to 12.5 tons. The contract called for a number of design improvements to the engine, gearbox, rotor head and structure; altitude performance and hot weather operating capability were also to be improved. Two of the improved flying cranes, designated CH-54B, were accepted by the US Army during 1969. The original JFTD12-4A engines were replaced by two Pratt & Whitney JFTD12-5As, each rated at 3,579kW, and a gearbox capable of receiving 5,891kW from the two engines was introduced. Single-engine performance was increased, since the new gearbox receives 3,579kW from one engine, compared with 3,020kW on the CH-54A. A new rotor system was also introduced, utilising a high-lift rotor blade with a chord some 0.064m greater than that of the blades used formerly. Other changes included the provision of twin wheels on the main landing gear, an improved automatic flight control system and some general structural strengthening throughout the aircraft. Gross weight was increased from 19,050kg to 21,318kg.
S-64E FAA certification of the improved S-64E for civil use was announced in 1969, for the transportation of external cargo weighing up to 9,072kg.
S-64F Designation of a commercial version of the S-64.
Specifications:
S-64A / CH-54A Tarhe Engines: 2 x Pratt & Whitney JFTD12-4A (military T73-P-1), 3356kW / 4500 shp Rotor dia: 72 ft (21.95m) Length: 70 ft 3 in (21.4m) Height: 18 ft 7 in (5.67 m) Empty weight: 8724 kg Max wt: 42,000 lb (19,050 kg) External load: 9400 kg Max. speed: 127 mph (204 km/h) at sea level Crew: 2 Payload: 90 pax or 17,500 lb (7937kg) in detachable pod Payload: 22,400 lb (10,160kg) under-slung Max speed: 204 kph Cruise: 169 km/h Service Ceiling: 2475 m Max. range: 253 miles (407 km)
S-64E / CH-54A Engines: 2 x Pratt & Whitney JFTD12-4A (military T73-P-1) turboshaft, 3,356kW / 4,500 hp for take-off / max continuous 2,983kW. Rotor diameter 72 ft Main rotor 6 blades Length: 70 ft 3 in Gross weight 42,000lbs Fuel capacity standard: 3,328 litres Auxiliary fuel capacity: 1,664 litres Max cruise speed 110kts Ceiling: 13,000 ft Range: 253 miles
S-64F / CH-54B Engines: 2 x Pratt & Whitney JFTD12-5A (military T73-700) turboshaft, 3579kW / 4800 hp for take-off / max continuous 3,303.5kW. Main rotor diameter: 21.95m Fuselage length: 21.41m Height: 5.67m Max take-off weight: 21318kg / 47,000 lb Empty weight: 8981kg / 19607 lb Equipped useful load: 27,371 lb Payload max fuel: 18,225 lb Max sling load: 25,000 lb Fuel capacity standard: 3,328 litres Auxiliary fuel capacity: 1,664 litres Disc loading: 11.5 lb/sq.ft Pwr loading: 6 lb/hp Service ceiling: 10,000 ft Max cruise: 100 kt Max range cruise: 100 kt Cruising speed: 169km/h Range with max fuel: 370km / 1.9 hr ROC: 1300 fpm HIGE: 7200 ft HOGE: 2100 ft Payload: 9000kg in a standard container Seats: 4
The forerunner of an entirely new generation of production models, the S-62 was the company’s first amphibious helicopter, with a boat hull and powered by a single General Electric T58 turbine.
S-62 prototype
The Sikorsky S-62 was the first turbine-powered helicopter to be granted a type approval certificate by the U.S. Federal Aviation Agency, and was also the first type to pass new regulations introduced by the FAA to govern the operation of commercial passenger-carrying helicopters.
The design, drawn up in 1957-58, was based on using identical main and tail rotors and transmission systems, and other dynamic and mechanical features, of the proven piston-engined S-55. The fuselage was entirely new, being designed for fully amphibious operation with a flying-boat hull and main undercarriage wheels semi-retractable within the two outrigged stabilising floats. Power was provided by a single General Electric shaft turbine engine, mounted centrally above the main cabin and accommodation provided for a 2-man flight crew and 10 airline passengers or 12 troops.
Two S-62 prototypes were completed, with 1050shp T58-GE-6 engines derated to 670shp. The maiden flight on 22 May 1958, and subsequent world-wide demonstration flights, were made by N880, while N972 carried out trials for the FAA type certificate which was awarded on 30 June 1960; and a few days later the first production machine, designated S-62A, was delivered to a commercial customer.
Later S-62A’s have CT58-100 or -110 engines of 1250 (derated to 730) shp. The S-62B is essentially similar to the A model, but employs the rotor system of the Sikorsky S-58 with the main blades shortened by 0.33m. In February 1962, after service trials with a modified S-62A, the U.S. Navy ordered four of these aircraft on 21 June 1962 as HU2S-1G’s (redesignated as HH52A’s on September 1962 before delivery) for the U.S. Coast Guard. Initial deliveries, under the designation HH-52A and named Seaguard, were made in January 1963. This version powered by a 932kW CT58-GE-8 engine was replaced by the HH-3 Pelican.
Sikorsky HH-52A
In all, ninety-nine were built; 1352 to 1379, 1382 to 1413, 1415 to 1429, 1439 to 1450, and 1455 to 1466.
The HH 52A can carry six litters and can hoist 600 pounds on a cable at¬tached to an electric winch with an explosive guillotine cutter. The engine is a GE turbine that generates 1,250 shaft horsepower, de¬-rated, on this Coast Guard version to only 830 shp by limiting the size of the fuel flow orifices.
HH-52s based at Houston, Texas, frequently practised recovery of the NASA Apollo astronauts. One US Coast Guard machine was used in the film Airport ’77.
Subsequent naval orders for the HH-52A had raised the total to eighty-four by mid-1968 and it has been in use since early 1963. The HH-52A has the T58-GE-8 engine, military version of the CT58-110, and automatic stabilisation equipment. Additional features for coastal search and rescue work include a fold-down rescue platform and boat-towing gear. A rescue hoist can be mounted above the starboard cabin door to lift a maximum load of 272kg, or the S-62A can lift a 1361kg slung load by means of an under-fuselage hook.
Originally designated S-62B, the 1958 S-63 was S-62 with S-58 rotor system,
The S-62C is the equivalent of the HH-52A for commercial and foreign military customers. Apart from the U.S. Coast Guard, which remains the largest user of the type, the biggest single operator of S-62’s is Petroleum Helicopters Inc, which has a fleet of six for work in support of offshore oil-drilling operations in the Gulf of Mexico. Of the forty-six S-62 type helicopters ordered, up to summer 1968, other than those of the USCG, nearly half were for customers in Japan, where Mitsubishi hold the licence. Nine examples were built under licence for service with Japanese Maritime Self- Defence Force (JMSDF).
By mid-1993, no military, and only a very small number of civilian, S-62s remain in use.
Officially listed as an HSS-2, the U.S. Navy’s BuNo. 148033 was actually a Sikorsky S-61F compound research helicopter sponsored by the Army and Navy. Sikorsky tested the S-61F compound helicopter, an SH-3A with a new, streamlined fuselage, fully retractable undercarriage, swivelling tail rotor and 9.75m span wings supporting two 1350kg Pratt & Whitney J60-P-2 turbojets engines to complement the two 1,200 shp General Electric T58-GE-8B turboshafts. The five-bladed rotor shown here was later replaced by a six-bladed rotor.
First flight as a compound helicopter was on 21 May 1965. This aircraft has reached a level speed of 390km/h.
The fuselage was used as ejection system test-bed for the S-72 RSRA.
Sam Grober, 22.01.2010 I was privileged to fly in that aircraft as a structural flight test engineer. The day I flew in it, we obtained 208kts, indicated, with the main rotor at low pitch, with almost zero MR thrust, with both J60’s at MC HP.
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.
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.
HSS-2
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.
SH-3D
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.
CH-3C
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.
Sikorsky CH-3C 1493
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.
Sikorsky HH-3F 1493
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.
Sikorsky S-61L N302Y
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.
S-61N
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.
BEA S-61N
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.
S-61R
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.
Sikorsky CH-3E ex-CH-3C 63-9676
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.
Royal Navy HAS.1 Sea King
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.
Westland Sea King HAS Mk.2 of 826 Sqn, HMS Tiger
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.
First Australian Navy Sea King Mk.50A
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.
Sea King HAEW Mk.2
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.
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
In May 1958 Sikorsky began design work on the Model S-60 twin-engined heavy-lift helicopter. The S-60 grew from the S-56/CH-37, using the same piston engines and dynamic components. It was built as a research vehicle to demonstrate the flying crane concept with a thin, strong fuselage, consisting of a central ‘backbone’ which supported the podded engines, main and tail rotor systems, and a nose-mounted crew cabin.
Bulk cargo and passengers were intended to be carried in large rectangular pods that could be attached to the underside of the aircraft’s central spine, whereas vehicles and other out-sized loads were to be sling-hoisted. It was capable of lifting a 5443kg payload beneath the fuselage boom, and the co-pilot could turn his seat to face aft to control loading and unloading.
One S-60 was built for Navy evaluation, first flown on 25 March 1959, the craft was found to be underpowered for its intended roles. The prototype S-60 crashed in April 1961, but by then Sikorsky had begun construction of an enlarged version, with a six-bladed main rotor driven by two 3020kW JFTD-12A turboshaft engines. Designated S-64, the prototype flew on 9 May 1962.
The S-60 Skycrane concept demonstrator, a modification of S-56, was displayed for many years at New England Air Museum (CT), but believed destroyed in a tornado that hit the museum.
In late 1953 the Army awarded Sikorsky a contract for the experimental conversion of two existing H-18 helicopters from piston to turbine power. The two aircraft selected for conversion were 49-2890 and -2891, the third and fourth H-18s built, with the former to be used for flight testing and the latter for static engineering evaluation. Sikorsky allotted the two craft the company designation S-59, and began the conversion work in early 1954.
On Jul 24, 1953 the S-52T (YH-18B) turbine powered version of the S-52 was first flown. It used a French Turbomeca Artouste I engine. A developed version designated YH-18B and powered by a T51-T-3 (Artouste) turbine is now re-designated XH-39.
Sikorsky H-39 49-2890
The H-39 retained the H-18’s basic pod-and-boom layout, but differed from the earlier machine in several ways. The H-39 was powered by a single 400shp XT51-T-3 Artouste II turbine engine, which drove a new, fully-articulated, four-bladed main rotor. Other changes included a modified tail rotor, strengthening of the fuselage, incorporation of retractable wheeled landing gear, and the addition of updated electronics.
The Model XH-39 (S-59), using a 400shp Continental XT51 turbine, was rejected by the US Army, despite its speed and the advantage of retractable landing gear, as being old-fashioned in design and unsuitable for further development. Instead, the Army chose the Bell XH-40 with a Lycoming XT53 turbine.
The H-39 was the Army’s first turbine-powered helicopter, and was for a time the world’s fastest rotorcraft.
On 29 August 1954 Army Warrant Officer Billy Wester flew a world speed record of 156 m.p.h / 251km/h over 3km was set up by Sikorsky XH-39.
On 17 October 1954 Army Warrant Officer Billy Wester flew a world height record of 24,500 ft / 7474m was set up by Sikorsky XH-39.
Sikorsky S-59 Engine: 1 x Continental/Turbomeca Artouste XT51-T-3 turboshaft, 300kW / 400 hp Rotors: 4-blade main 3-blade tail Main rotor diameter: 10.0m / 35 ft Fuselage length: 11.95m / 30 ft 3 in Height: 2.99m Max take-off weight: 1226kg / 3,560 lb Empty weight: 749kg Max speed: 176km/h / 156 mph Ceiling: 24,500 ft Hovering ceiling, IGE: 2804m Service ceiling: 4724m Range: 670km Typical range: 253 miles at 138 mph Seats: Pilot and 3 passengers, 800 lb. cargo or 2 stretchers and attendant.
Designed to overcome the range and offensive payload deficiencies of the anti-submarine HO4S version of the S-55 / H-19, the Sikorsky S-58 was developed to a US Navy order for a prototype XHSS-1 placed on 30 June 1952. The nose engine position was retained for the 1525hp / 1137kW Wright R-1820 engine, but a completely new semi-monocoque fuselage, larger-diameter four-bladed main and four-bladed tail rotors, and transmission system were introduced, together with main rotor and rear fuselage folding to facilitate shipboard stowage. The tail rotor has servo control and both main and tail rotors have brakes. Fuel capacity is from 750 litres to 1,164 litres depending on model.
With a completely redesigned, downward-sloping tail section, the S-58 also differed from the S-55 in having a three-point, tail-wheel landing gear. Air-oil shock-absorber struts. Mainwheels have rotating struts to reduce drag and weight and toe-operated brakes. Tailwheel is fully castoring and self-centring, with an anti-swivelling lock. Mainwheel tyres 11.00 x 12. Tailwheel tyre 6.00 x 6. Toe-operated mainwheel brakes. Track 3.66m. Wheelbase 8.75m.
Pilot’s compartment above main cabin seats two side by side with dual controls. Cabin normally seats 12 passengers. Up to eight stretchers can be carried. Sliding windows of pilot’s compartment removable in an emergency. Cabin and cockpit air conditioned and soundproofed.
Designated XHSS-1, it flew for the first time on 8 March 1954.
Designated XHSS-1, it flew for the first time on 8 March 1954. Three were built, 134668 to 134670, later redesignated as YHSS-1. They were again redesignated, as YSH-34G, in 1962.
After evaluation of the XHSS-1 an initial ten were ordered. The first production HSS-1 flew on 20 September 1954, and the type became operational in August 1955. A total of 215 were built: 137849 to 137858, 138460 to 138493, 139017 to 139029, 140121 to 140139, 141571 to 141602, 143864 to 143960, and 145660 to 145669, of which six were transferred to the USAF and in turn to Brazil (60-5424 to 5429) and six to the USCG as HUS-1G (1332 to 1336, and 1343). All redesignated as SH-34G in 1962.
Now designated SH-34G, it has the name Seabat and carries either dunking sonar search equipment or weapons for attacking submarines.
The 1957 HSS-1F was HSS-1 converted with two General Electric YT58-GE engines. Girst flown on 30 January 1957 and redesignated as SH-34H in 1962.
Later Seabats includes the ‘winterised’ LH-34D (formerly HSS-1L). These models in U.S. Navy service were replacement by the SH-3 Sea King and many were converted to utility transports with UH prefixes. Subsequent production orders totalled 427 (53-4475 to 4554, 54-882 to 937, -2860 to 2914, -2995 to 3050, 55-5241 to 5261, 56-4284 to 4342, 57-1684 to 1770, and 58-1721) included 21 transfers from the USN. Redesignated as CH-34A in 1962. In addition to redesignated ships, 21 H-34As were rebuilt as CH-34C.
One JH-34A was built; 53-4475.
The HSS-1N (SH-34J) was developed for night operations, equipped with Doppler for navigation, automatic stabilisation and automatic hover coupler. A single prototype YHSS-1N 143957 was built, redesignated as YSH-34J in 1962.
Production HSS-1N possibly totalled 167 including 145670 to 145712, 147631/147635, 147984/148032, 148934/148963, 149082 to 149087, 149131 to 149133, 149840 to 149842, 150730 to 150732, 150808 to 150819, and 150821 to 150822, of which 11 were procured as SH-34J (150733 to 150807) might also have been built and the total may or may not include exports to Chile, Germany, Italy, and the Netherlands, as well as some transferred to USAF as HH-34J.
A single HSS-1F (SH-34H) flown on 30 January 1957, was powered by two General Electric T58 turboshafts. In 1960 five HSS-1Z (VH-34D) helicopters joined the Executive Flight Detachment for Presidential and VIP transport duties. Seabats stripped of ASW equipment for utility duties were designated UH-34G and UH-34J.
In 1959 a US Marine Corps HUS-1 served as a launching platform for the Martin Bullpup air-to-surface missile during a series of tactical assault trials at Chesapeake Bay.
The Bullpup was claimed to be the largest radio-controlled missile ever fired from a helicopter.
A troop transport variant was simultaneously acquired by the Marine Corps as the HUS Seahorse. One example of this type was loaned to the Army for service test and evaluation. The Army had placed preliminary orders for production H-34A troop transport variants of the Navy XHSS-1 in April 1953 and the performance of the borrowed Marine Seahorse, essentially identical to the H-34 version, confirmed the Army’s belief that the type would be a vast improvement over the H-19s then in service.
H-34B were 1960 H-34A conversion, redesignated as CH-34B in 1962.
The US Marine Corps ordered the HUS-1 Seahorse (UH-34D) version on 15 October 1954; able to carry 12 Marines or a 1350kg load, this variant entered service in February 1957. The Marines received 570 of the S-58 in the utility version (HUS-1 / UH-34D and -1A, 143961 to 143983, 144630 to 144654, 145713 to 145812, 147147 to 147201, 148053 to 148122, 148753 to 148822, 149318 to 149402, 150195 to 150264, 150552 to 150580, 150691, and 150717 to /150729) and have used the type since 1957 primarily for utility transport and for recovery duties connected with the U.S. satellite programme. The 12-passenger UH-34D and UH-34E (formerly HUS-1 and HUS-1A / UH-34E) are basically alike, the latter being an amphibious version (eight built, 144655 to 144662 and 32 converted from HUS-1) with pontoons for landing on water. Inflatable flotation gear identified the US Marines’ HUS-1A and the US Coast Guard’s HUS-1G (Redesignated as HH-34F in 1962). Four HUS-1L (LH-34D) helicopters were modified for operation in the Arctic. Production continued as redesignated UH-34D after 18 September 1962.
The six 1958 HUS-1G were converted HSS-1 for the USCG. The six, 1332 to 1336, and 1343, were redesignated as HH-34F in 1962.
Four HUS-1, including 144658, 145719, and 150220, were modified for Antarctic duty. They were redesignated as LH-34D in 1962.
Eight HUS-1, 147161, 147179, 147191, 147201, 148803, 148804, 148805 and 150691, were converted as HUS-1Z Presidential aircraft. They were redesignated as VH-34D in 1962.
A total of 603 S-58s were delivered to the US Marines.
The US Army ordered several hundred H-34A, H-34B and H-34C Choctaw helicopters powered by 1063kW R-1820-84 engines and each carrying 16 troops or eight stretchers in the medevac role.
The Army accepted the first of 437 new-construction H-34As in April 1955, the first unit being equipped in September 1955. An additional twenty-one HUS-1 aircraft transferred from the Marine Corps during Fiscal Year 1955 were also designated H-34A (though at least five further USMC Seahorses operated by the Army between 1955 and 1957 retained their original Navy Bureau numbers).
In 1956 an early production example flown by Army Captains Claude E. Hargett and Ellis Hill set new world helicopter speed records on courses of 100 km (141.9mph), 500 km (136mph) and 1000km (132.6mph).
The H-34A was also the first helicopter judged safe enough for routine use by the U.S. President, and in 1957 the Army organized an Executive Flight Detachment equipped with specially modified Choctaws. These aircraft were fitted with extensive soundproofing, plush VIP interiors, and upgraded communications equipment, and were designated VH-34A.
The US Army H-34A, H-34B and H-34C Choctaw helicopters were powered by 1063kW R-1820-84 engines and each carrying 16 troops or eight stretchers in the medevac role. US Army CH-34s maintained a constant patrol along the border of West Germany with Czechoslovakia and East Germany. Army S-58’s have the name Choctaw, the CH-34A and CH-34C differing only in the equipment carried.
The H-34C, with SAR modifications, included 56-4305, -4331, -4333, 57-1692, -1698, -1709, and others. They were redesignated as CH-34C in 1962 along with 21 rebuilt and re-serialed H-34As (63-13190 to 13210.
In 1960 Sikorsky began modifying Army H-34As (and Air Force H-34As and -Bs) to -C model standard through the addition of automatic flight stabilization systems and other detail changes including relocation of Battery, Invertors, and Aux Hyd Reservoir. By January 1962 the Army had 190 H-34Cs and 179 H-34As in its inventory; under the Tri-Service designation system introduced later that year the aircraft were redesignated as, respectively, CH-34C and CH-34B. Several -C model aircraft were subsequently modified to VH-34C standard for VIP transport duties. The VH-34D is a VIP transport.
In 1964 U.S. Marines flying the HUS-1 version of the S-58 saved 1,500 Vietnamese villagers from floodwaters. The aircraft also was used to recover the space capsule of Alan B. Shepard, Jr., America’s first astronaut in space.
HSS-1
Twenty-three UH-34D went to USAF for export to friendly nations (63-8248/8259, -13006/13014, and -13139/13140) and 44 to USN (152686, 153116/153133, 153556/153558, 153695/153704, 154045, 154889/154902, and 156592/156598), of which 10 went to USAFR as HH-34D with new s/ns (60-6913, -6923, 61-4488/4491, -4529, 63-7972/7974).
The CH-34 did not see extensive Army service in Vietnam. The Army’s 1962 decision to deploy the Vertol CH-21 Shawnee to Southeast Asia instead of the faster and more capable Choctaw was based on two considerations. First, in accordance with then-current Army doctrine regarding the area-standardization of aircraft types, the CH-21 was already widely deployed in the Pacific area and the continental United States, whereas all but about thirty of the Army’s CH-34s were based in western Europe. US Army CH-34s maintained a constant patrol along the border of West Germany with Czechoslovakia and East Germany. It was therefore logical and logistically preferable that the CH-21, which was considered acceptable if somewhat past its prime, should be chosen for deployment to Southeast Asia. The Army’s second reason for sending the Shawnee rather than the Choctaw was a somewhat negative opinion of the Choctaw’s combat survivability, a belief based on French experience in North Africa. French forces had used both the CH-21 and the CH-34 in Algeria, the former flown by the Army and Air Force and the latter by the Navy, and official evaluations had indicated that the Shawnee was more likely to survive multiple hits by ground fire than was the CH-34. The French belief that the location and ‘fragile’ construction of the Choctaw’s fuel tanks made the craft extremely vulnerable to ground fire seemed to validate the U.S. Army’s decision to deploy the Shawnee to Vietnam pending the introduction into widespread service of the UH-1 Iroquois. The approximately twenty Army H-34s that did eventually reach Vietnam proved no more vulnerable than any other aircraft in the theatre, however, and ably carried out missions ranging from combat assault to aeromedical evacuation and general cargo transport. Most of these twenty aircraft were turned over to the South Vietnamese during the course of the war, though a few were ultimately reclaimed by the Army prior to the final collapse of the Saigon Government.
One SH-34G was exported to Germany; 152188.
SH-34J production in 1962 was for the USN (151729 to 151731, 152380 to 152381, and 153617 to 153622) of which several transferred to the USAF as HH-34J.
The CH-34 Choctaw remained in frontline Army service well into the late 1960s, and was standard equipment in many Army Reserve and National Guard aviation units for considerably longer. The last Choctaw was not officially retired until the early 1970s, by which time the type’s duties had been divided between the UH-1H Iroquois and the CH-47 Chinook.
The commercial S-58B and S-58D are passenger/cargo transport helicopters comparable with their military counterparts. The 12-seat airline version, certificated by the FAA in August 1956, was built for Chicago Helicopter Airways (eight), New York Airways (three) and Sabena (eight). First commercial deliveries of S-58C were made in 1956-57.
Substantial numbers of military S-58 variants have been exported, and in mid-1967 were serving with the Federal German Army (one hundred and forty-four); the navies of Argentina (five), Brazil (five), France (twenty-six), Germany, Indonesia, Italy (eighteen), Japan (fourteen) and the Netherlands (twelve); and the air forces of Belgium (nine), Cambodia (three), Canada (four), France (one hundred and ten), Germany, Israel (twelve), Thailand (twenty) and South Vietnam (sixty). Those in French and Belgian service were manufactured in France by Sud-Aviation.
Up to 1970 2,261 total all S-58s were built and production of the S-58 ended in December 1965 after 1766 had been built by Sikorsky, but started again to fulfil additional U.S. orders and one from the Italian Navy for six SH-34J’s.
In January 1970, Sikorsky announced the design of kits for the conversion to turbine power by the installation of the Pratt & Whitney PT6 Twin-Pac. First flight of the S-58T took place 19 August 1970 and in April 1971 Sikorsky received FAA approval for the S-58T PT6A Twin Pac-powered turbine conversion for H-34 airframes. One hundred and forty-six conversions, or conversion kits, were produced until, in 1981, the rights were sold to California Helicopter International. Since then customers for the California Helicopter (Sikorsky) S-58T included New York Airways, the Indonesian and South Korean air forces (now retired) and the government and air force of Thailand. The S-58T is also in service in Argentina with the Presidential Aircraft Squadron. Small numbers were built of S-58B and S-58D civil passenger and cargo transport helicopters, a 12-seat airline version being operated by Chicago Helicopter Airways, New York Airways and SABENA.
When he checked in for a Sabena S-58 flight, Igor Sikorsky was asked if his name was spelt like the helicopter’s.
When production was terminated in January 1970, Sikorsky had manufactured a total 1,820 S-58s of all versions.
The S-58T is a turbine conversion of the normally piston engined military H 34, or civilian S¬58, with the Curtiss Wright R 1820 piston radial engine removed from the nose and replaced by a pair of turbines fastened to a common drive transmission as the PT6T Twin Pac.
The PT6T Twin Pac unit fitted to the S-58T is basically two PT6 turboshaft engines mounted side-by-side and driving into a combining gearbox. Of the total 1800 shp available, only 1505 shp can be absorbed by the transmission during take-off and for continuous operations this is limited to 1254 shp. Should one engine fail, sensors automatically increase the good engine’s output up to the maximum 900 shp. Fuel is carried in 12 under-floor cells.
The useful load rose about 200 pounds on the Standard S 58T, it actually went down by some 80 pounds on the Mark II version, which has airline seating and windows. This increased power from 1,525 hp to 1,875 shp. Since the basic rotor blade system has been retained, there would also seem to be a speed handicap there that no amount of extra power could overcome.
By 1975 more than a hundred S 58Ts had been delivered or are under contract, more than half of them in the form of retrofit kits.
S-58T
The S-58T was first flown on 26 August 1970 with P&WC PT6T-3 twinpack turboshaft engine. Kits were built by Sikorsky but 160 conversions were carried out by California Helicopter International.
S-58T
Offering a 5,000 pound sling load, the Sikorsky S 58T has a 110 knots normal cruise, a 10¬knot edge on both the 212 and the 205A. Furthermore, while all three aircraft can hoist a 5,000 pound sling load, the 58T can do it at higher altitudes. The S 58T manages a gross lift at 6,500 feet.
When properly equipped, it’s IFR for two. Outsized wheel hubcaps house automatically inflatable bubbles for inadvertent oceanic dunking. With an engine out, though, the aircraft can hold onto a service ceiling of 4,300 feet.
While it turns out that the 430 pound weight saving gained by substituting the twin turbines for the old recip engine was pretty well swallowed by updating modifications, there was no loss of range with the same 283 gallons of fuel. Though the new turbines consume an extra 22 gph in cruise, the higher 110 knot cruise (versus 85 knots for the pis¬ton model) yields almost exactly the same 243 nm range at sea level.
Furthermore, the hovering altitude in ground effect on a warm day (ISA + 20) went way up from 2,600 feet in the piston model to 7,700 feet in the S 58T.
Whereas the “old” rotor blade system the 58T is saddled with might have seemed a handicap, the engineers at Sikorsky finessed their way around that by smoothing out the vibration levels, and that, in turn, permitted the boost in cruise speed, rather than the addition of brute power.
Instead of adopting the “Nodamatic” vibration damping technique used by Bell, where the cabin is “suspended” at harmonic vibration points, Sikorsky used something called a Bifilar vibration absorber. This consists of weights fastened to the main rotor hub between the rotor blades more specifically, “pendular dynamic masses.” The 120 pound installation not only provides a five to one reduction in vibration levels, according to Sikorsky engineers, but it greatly reduces tail stresses, mechanical failures and overall maintenance.
In addition to the California Helicopters version, Orlando Helicopters also offers S-58 conversions. An S-58 Heli-Camper, similar in fit to the OHA-S-55 Heli-Camper is available, powered by a Wright Cyclone R-1820-84 engine. A further Orlando S-58T conversion is the Orlando Airliner, an 18-seat all-passenger version with nine additional tinted windows fitted on each side of the cabin. By 1997 nearly 30 conversions have been completed.
Total of 166 also produced under licence by Sud-Aviation in France. Sud-Aviation were completing two modified examples of the Sikorsky S-58, each of which was fitted with a 1900shp Turbomeca Bi-Bastan shaft turbine engine, and the first of these machines flew on 5 October 1962. The S-58 development was not pursued.
After acquiring a licence in 1956 to manufacture the Sikorsky S-58 helicopter, Westland imported one of these aircraft in HSS-1 configuration. Given the British serial number XL722, this aircraft was test-flown for a time with its original 1525hp Wright R-1820-84 engine before being modified to accept a 1100shp Napier Gazelle NGa.11 gas turbine.
Napier Gazelle powered Wessex first flight 17 May 1957 at Yeovil
In its new form it was flown for the first time on 17 May 1957, and was later joined by two pre-production Wessex HAS Mk.1’s for Naval trials; the first of these flew on 20 June 1958.
Wessex features – Main and tail rotor each have four blades. Blades attached to hub by taper bolts. Main rotor blades fold manually. Rotor brake fitted. Shaft drive to main rotor through double epicyclic gear. Shaft drive to tail rotor through intermediate and tail gearboxes. Tail end folds to port and forward for stowage. Tail rotor carried at tip of vertical stabilising fin. Small horizontal stabiliser inset in leading-edge of fin.
All blades of light-alloy extruded spar and light-alloy bonded trailing-edge structure. The fuselage is a light-alloy semi-monocoque structure, with steel tube support structure for main rotor gearbox.
Landing gear is a non-retractable tailwheel type. All three units fitted with Westland oleo-pneumatic shock-absorber. Dunlop wheels, tyres and hydraulic disc brakes. Tubeless treaded mainwheel tyres, size 6.00 x 11. Tailwheel tyre size 6.00 x 6.
Compressor bleed air for heating. Ambient air circulation by fan. High-pressure hydraulic system for powered flying controls and 272kg capacity hoist. 24V DC electrical system, with two 6kW generators.
The HAS Mk.1, powered by a Napier Gazelle of 1,450shp (1081kW), went into production in 1959 for the Royal Navy as a submarine search and strike helicopter equipped with dipping Asdic and provision for one or two homing torpedoes. Powered by a 1450shp Gazelle Mk.161 engine, it began service trials with No.700H Flight in April 1960 and has since been delivered to Nos. 706, 737, 771, 815, 819 and 848 Squadrons. The first of these to commission, in July 1961, was No.815; the Wessexes of No.848 Squadron were for commando assault duties aboard H.M.S. Albion, having the ASW gear removed to make room for 16 troops or 8 stretchers and a medical attendant in the main cabin. Alternatively, a slung load of 1814kg can be suspended from an under-fuselage hook.
The original version was the Wessex HAS.Mk1, powered by a Napier Gazelle of 1,450shp (1081kW). The HAS.1 was undergoing service trials with No.700H Sqn during 1960, during which it first landed on an aircraft carrier.
The HAS.1 was supplanted by the Wessex HAS.Mk3 version popularly called the Camel because of its humpbacked search radar above the rear fuselage.
The most extraordinary feature of the Wessex HAS.3 is the stack of avionics and anti-submarine gear that the Royal Navy has fitted it with; the latter consisting of radar and sonar equipment linked together by a small computer to give a “total picture”. All this is operated by a third crewman seated at the rear of the aircraft, in an area which looks like a second cockpit. The sophisticated radar is used for navigation as well as sub hunting.
In August 1964 it was announced that the Iraqi Air Force was acquiring 12 Wessex HC.2. The cost was to be $8m including spares. The Gahanaian air force ordered two Wessex Mk.53.
Much more important numerically is the Wessex HU.Mk 5 version, the Royal Marine Commando assault ver¬sion. These twin engine machines once numbered almost 100. The Navy’s HU Mk.5, for which two orders were placed, entered service in summer 1964 as a commando-carrier assault transport.
In the early 1960s the RAF required a powerful general-purpose helicopter capable of troop-carrying, air ambulance and ground attack roles.
Following the first flight of the true prototype (XR588, this being preceeded by one of the Royal Navy pre-production variants which was later partly converted to an HC.2 version) on 5 October 1962, seventy-one examples of the Wessex HC.2 variant were delivered to the RAF, which first entered RAF service with No.18 Squadron, based at RAF Odiham, Hampshire, in January 1964, replacing the Whirlwind and Belvedere types. The HC Mk.2 was built as a transport helicopter for up to 16 troops, with redesigned gearbox and strengthened airframe.
And doors on each side of flight deck and on starboard side of cabin. Two flexible fuel tanks under cabin floor, total capacity 1,409 litres. Provision for carrying two 500 litre auxiliary tanks in cabin for ferry purposes. Refuelling point in starboard side of fuselage. Oil capacity 9 litres per engine, 19 litres in main gearbox.
Towards the end of 1959 two Whirlwinds joined the Queen’s Flight, designated HCC Mk.8, they had Alvis Leonides Major engines and special interiors.
HCC Mk.8
Westland Wessex HC Mk.2
In 1968 Westland Helicopters received an order for two Wessex aircraft to equip The Queen’s Flight. These were designated HCC4. The aircraft were built to HC2 standard but with the main cabin having a VIP interior finish, furnishings and sound proofing plus an external folding step below the cabin door. Additional Decca navigation equipment was installed on the flight deck. The first flight took place on 17 March 1969. The first official flight was on 1 July 1969 in support of the Investiture of the Prince of Wales at Caernarfon Castle, Wales. The helicopters in their distinctive red/dark blue paint scheme operated for many years from RAF Benson. From 31 March 1995 they moved to RAF Northolt and became part of No.32 (The Royal) Squadron. The Wessex HCC4 was retired in 1998 and No.32 (The Royal) Squadron gave up the task of providing helicopters for the Royal Family.
A commercial version was known as the Srs.60.
The RAAF ordered 27 Westland Wessex Mk31B carrier-borne anti-submarine/search & rescue helicopter from Westland Aircraft Ltd in July 1961. The first was delivered on 1 Nov 1962 and the last on 4 Nov 1963. The HAS Mk.31’s are similar to the HAS Mk.1 apart from their 1540shp Gazelle Mk.162 engines. Australia’s navy anti-submarine duties started in August 1962.
Westland built 356 Wessex in all (including those for the civil market): the HAS Mk.1 version for the Royal Navy; the HC Mk.2 tactical transport version for the RAF; the HAS Mk.3 antisubmarine version with 1550shp Gazelle NGa.18 turbine; the HU. Mk.5 for various roles on the Navy’s commando carriers; the HAS Mk.31 for the Royal Australian Navy; the Wessex Mk.52 for the Iraqui Navy (12); the Wessex Mk.53 for Ghana (3); the Wessex Mk.54 for Borneo and the Wessex Mk.60 commercial version. Seven Wessex Mk.60’s have been built for Bristow Helicopters Ltd. These are 10-passenger commercial equivalents of the Mk.2 and operate in support of the oil and gas drilling rigs in the North Sea.
CH-34A/H-34A Choctaw: Transport and general purpose helicopter for US Army.
CH-34C (formerly H-34C) Choctaw: Similar to CH-34A, but with airborne search equipment.
LH-34D (HSS-1L): Winterised version of Navy Seabat.
SH-34G (HSS-1) Seabat: Anti-submarine version ordered by US Navy 30 June 1952; accepted for service in February 1954.
SH-34J (HSS-1N) Seabat: Improved version of SH-34G.
UH-34D (HUS-1) Seahorse: Utility version for Marines; ordered 15 October 1954 and accepted for service January 1957.
UH-34E (HUS-1A) Seahorse: Version with pontoons for emergency operation from water.
VH-34D (HUS-1Z): VIP transport version of Seahorse.
S-58B: Commercial passenger/freighter version.
S-58C: Commercial passenger-carrying version with two doors on starboard side of cabin.
S-58D: Commercial passenger/freighter version.
S-58T: Turbine conversion with Pratt & Whitney PT6 Twin-Pac, comprising two PT6 engines and combining gearbox; improved performance includes greater speed and lifting power, and better hot-and-high operation.
Westland Wessex HAS. Mk 1 Initial production version, developed for the Royal Navy, with one 1,450shp Napier Gazelle 161 turboshaft engine. Re-engined with a 1,100shp Gazelle NGa.11, flew for the first time 17 May 1957.
Westland Wessex HC. Mk 2 High-performance development of the Mk 1 with two coupled 1,350shp Bristol Siddeley Gnome Mk 110/111 turboshaft engines. Power limitation of 1,550shp at rotor head. Prototype converted from Wessex 1, flew for the first time 18 January 1962, and the first production model (XR588) 5 October 1962.
Westland Wessex Mk 3 Similar to Mk 1, but with 1,850shp Gazelle NGa.18 165 turboshaft engine.
Westland Wessex HCC. Mk 4 Queen’s Royal Flight helicopter.
Westland Wessex HC. Mk 5: SAR helicopter of the Royal Air Force based in Cyprus.
Westland Wessex HU. Mk 5 Similar to Mk 2, for Commando assault duties from carriers of the Royal Navy. Design work began in April 1962 and construction of the prototype was started in May 1962. In service with A&EE (1) and 84 Squadron Akrotiri Cyprus (5).
Westland Wessex HAS. Mk 31 Generally similar to Mk 1, but with a 1,540shp Gazelle Mk 162 engine. Ordered for the Royal Australian Navy for anti-submarine duties from HMAS Melbourne.
Westland Wessex Mk 52 Similar to Mk 2, for Iraqi Air Force.
Westland Wessex Mk 53 Similar to Mk 2, for Ghana Air Force.
Westland Wessex Mk 60 Civil version in service with Uruguayan Navy.
Specifications:
Sikorsky S-58 / H-34 Choctaw Engine: 1 x Wright R-1820, 1137kW / 1504 hp Main rotor diameter: 56 ft / 17.1m Length: 17.3m Height: 4.9m Max take-off weight: 6350kg Empty weight: 3754kg Max speed: 178 km/h / 150 kt Cruising speed: 158km/h Rate of climb: 5.6m/s Service ceiling: 2900m Range: 450km Crew: 2 Passengers: 12-18
CH-34A/H-34A Choctaw Transport and general purpose helicopter for US Army. Engine: 1,525 hp Wright R 1820 84B/D piston. Rotors: 4-blade main; 4-blade tail. Operating speed: 40 – 128 knots Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft Seats: 20
CH-34C / H-34C Choctaw Similar to CH-34A Operating speed: 40 – 128 knots Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
LH-34D / HSS-1L Winterised version of Navy Seabat. Engine: 1,425 hp Wright R-1820 Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
SH-34G / HSS-1 Seabat Anti-submarine version ordered by US Navy 30 June 1952; accepted for service in February 1954. Engine: 1,425 hp Wright R-1820 Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
HSS-1F / SH-34H Engines: two General Electric YT58-GE Length: 47’3″
SH-34J / HSS-1N Seabat Improved version of SH-34G. Engine: 1,425 hp Wright R-1820 Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
UH-34D / HUS-1 Seahorse Utility version for Marines; ordered 15 October 1954 and accepted for service January 1957. Engine: Wright R-1820-84 Main rotor: 56’0″ Length: 46’8″ Max speed: 123 mph Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
UH-34E / HUS-1A Seahorse Version with pontoons for emergency operation from water. Cabin length: 13 ft
VH-34D / HUS-1Z VIP transport version of Seahorse. Mainwheel tyres 11.00 x 12 Tailwheel tyre 6.00 x 6 Wheel track 3.66m Wheelbase 8.75m Cabin length: 13 ft
S-58B Engine: 1525hp Wright R-1820-84 Useful load: 5150 lb Max speed: 130 mph Cruise: 101 mph Range: 247 mi Ceiling: 9,500 ft
S-58C Commercial passenger-carrying version with two doors on starboard side of cabin. Engine: 1 x Wright R-1820-84, 1137kW Main rotor diameter: 17.1m Length: 17.3m Height: 4.9m Max take-off weight: 6350kg Empty weight: 3754kg Max speed: 198km/h Cruising speed: 158km/h Rate of climb: 5.6m/s Service ceiling: 2900m Range: 450km Crew: 2 Passengers: 12-18
S-58D Commercial passenger/freighter version.
S-58T Turbine conversion with Pratt & Whitney PT6 Twin-Pac. Engine: P&W PT6T-3 coupled turboshaft, 1525 shp Length: 50 ft 11 in Width: 5 ft 8 in Height: 15 ft 11 in Rotor dia: 56 ft MTOW: 13,000 lb Useful load: 5600 lb Slung cap: 5000 lb Fuel cap (useable): 286 USG Endurance: 2 hr 40 min Max cruise: 110 kt Max speed: 124 kt Fuel consp (cruise): 106 USG/hr Range (cruise speed, 20 min res): 260 nm HIGE: 8950 ft SE ceiling; 2100 ft Crew: 2 Pax cap: 17
S 58T Mark II Engine: UACL PT6T-6, 1,875 shp Main rotor dia: 56 ft Length: 50 ft. 11 in Height: 15 ft. 11 in Disc loading: 5.28 lb/sq.ft Seats: 10 16 Empty weight: 8,354 lb Useful load: 4,446 lb Payload with full fuel: 1,924 lb MTOW: 13,000 lb Power loading: 8.54 lb/hp Fuel capacity (standard): 283 USG/1,910 lb Fuel capacity (optional): 433 USG/2,923 lb ROC: 1,275 fpm Service ceiling: 12,000 ft Single engine service ceiling: 4,200 ft Vne @ 2,000 ft: 124 kt Normal cruise @ 2,000 ft: 110 kt Range @ normal cruise (45 min res. std tanks): 200 nm Endurance @ max cruise (no res, std tanks): 2.6 hr Range max fuel/ cruise: 401 nm/ 3.2 hr Range max fuel / range: 346 nm/ 3.2 hr ROC: 1260 fpm Max sling load: 5000 lb Hovering ceiling in ground effect: 10,400 ft Hovering ceiling out of ground effect: 6,500 ft
Westland Wessex Licence-produced UK version.
Westland Wessex HAS.I Engine: 1 x Napier Gazelle Mk.161, 1450 shp Main rotor diameter: 56 ft Length: 49 ft 11 in Height: 15 ft 10 in Main rotor disc area: 2460 sq.ft Empty weight: 7600 lb MTOW: 12,600 lb Fuel capacity: 266 gal Aux fuel capacity: 200 gal Max speed: 132 mph at SL Cruise sped: 115 mph Sevice ceiling: 14,200 ft Max range w/aux fuel: 600 mi
Westland Wessex HC Mk.2 Engine: 2 x Bristol Siddeley Gnome Mk.110 or Mk.111 turboshaft, 1007kW / 1350 shp total Type 10 coupling gearbox Rotor head rating: 1,550shp Main rotor diameter: 17.07m Length rotors turning: 20.04m Height: 4.93m Max take-off weight: 6123kg Empty weight: 3767kg Max speed: 212km/h Range with max fuel: 769km Crew: 1 -3 Capacity: 16 seats
Westland Wessex HC Mk.5 Engines: One Bristol Siddeley Gnome Mk 112 and one Gnome Mk 113 Type 11 coupling gearbox Main rotor diameter: 17.07m Length rotors turning: 20.04m Height: 4.93m Crew: 1 -3 Capacity: 16 seats / 1814 kg
Westland Wessex HU.Mk 6 Engine: one Rolls Royce Coupled Gnome twin turboshaft with two pow¬er sections each rated at 1,350 shp (1007 kW), combined output limit 1,550 shp (1156 kW). Main rotor diameter 17.07 m (56 ft 0 in) Length overall 20.03 m (65 ft 9 in) Height 4.93 m (16 ft 2 in) Main rotor disc area 228.81 sq.m (2,463.0 sq ft). Empty weight 3927kg (8,6571b) Maximum take off weight 6120 kg (13,500 lb) Maximum speed 214km/h (133mph) Cruising speed 195 km/h (121 mph) Range 769 km (478 miles) Armament: role kit can include two 7.62 mm (0.3 in) GPMGs firing ahead, one or two 20 mm cannon, two or four AS. 11 wire guided missiles, or rocket pods.
Westland Wessex Mk.31B Engine: 1 x 1,575 shp Napier Gazelle 161 free turbine Rotor diameter: 56 ft Length 65 ft 10.5 in Folded length: 38 ft 6 in Height: 14 ft 10 in Empty weight: 8,000 lb Loaded weight: 13,500 Initial Rate of Climb: 1,540 ft/min Ceiling: 14,100 ft Speed: 108 knots Range: 262 nautical miles Bomb load: 2 x torpedoes (external) Crew: 4
All Aero 