Helicopters

Sikorsky S-55 / Chickasaw / H-19 / HO4S / HRS / Westland WS.55 Whirlwind / Orlando Helicopter Airways Inc OHA-S-55 Bearcat / Sud-Est Elephant Joyeuse

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S-55

On 1 May 1949, Sikorsky’s technical department was tasked to create a new helicopter in seven months, which would be capable of carrying ten passengers in addition to a crew of two.

The H-19 was of all-metal pod-and-boom construction, had quadricycle wheeled landing gear, and carried its single piston engine in its nose. The engine was linked to the gear drive of the three-bladed main rotor by a long extension shaft, and was easily accessible via two large clamshell doors. The arrangement of powerplant and drivetrain allowed the placement of a large and unobstructed box-like passenger/cargo cabin directly below the main rotor blades, thus ensuring that loads of varying sizes and composition would not adversely affect the craft’s centre of gravity. The H-19’s two-man cockpit was placed above and slightly forward of the passenger/cargo cabin, with the seats placed one either size of the drive shaft, and offered excellent visibility to the front and sides. The craft’s high-set tailboom carried a vertical tailplane and a two-bladed anti-torque rotor, and was faired into the rear of the fuselage by a triangular fin.

Sikorsky S-55 Article

Special attention was paid to the maintenance. The main parts were easily dismantled in an average of 12-15 hours and were all designed for ease of access (the engine, for example, could be changed in two hours, even without special equipment, and daily inspections took a maximum of 15-20 minutes). The S-55 had a monocoque metal fuselage with aluminum and magnesium light alloy bulkheads and skin. Except for the chrome-molybdenum steel-tube rotor pylon, structure is of aluminium and magnesium semi-monocoque construction. The three-blade main rotor had long-life metal blades (they demonstrated a life of over 20000 hours in lab tests). The main rotors are nitrogen filled with a hub mounted integral meter. The fuel was contained in two crash resistant tanks situated beneath the cabin in the lower part of the fuselage and had a total capacity of 700 liters. Each leg of the quadricycle undercarriage had its own shock absorber for maximum stability during take-off and landing and manoeuvres on the ground. Wheel track 3.35m. Floats could also be fitted to the legs for emergency landings on water, or the undercarriage could be replaced by permanent metal amphibious landing gear or permanently inflated rubber bag flotation gear. For use with the normal wheels, ‘doughnut’ pontoons were available which are stowed deflated on each wheel axle and can be inflated in under 5 seconds, when needed for landing on water.

The pilot’s compartment above main cabin seats two side by side with dual controls. Cabin located below main lifting rotor may seat from 7 (commercial) to 10 (military) passengers, the 10 passengers being seated three against front and rear walls and two on each side, all facing inwards. Up to six stretchers may be carried, which can be loaded by optional hydraulic power-operated hoist while aircraft is hovering. Pilot’s compartment may be entered from the outside or from the cabin so that co-pilot may act as attendant.

Engines were one Pratt & Whitney R-1340 S3H2 Wasp radial air-cooled engine rated at 410kW at 1,525m and with 447kW available for take-off at 915m, or one Wright R-1300-3 radial air-cooled engine rated at 522kW at 2,222m and with 596kW available for take-off at 1,675m. Engine on angular mounting in nose of fuselage with sloping shaft drive to rotor gear box below head. With the R-1300 engine, a hydromechanical clutch with free wheel system is used in the drive to the main transmission, and the drive-shaft from the free wheel unit to the main transmission has flexible rubber couplings on each end. Large clamshell doors in nose of fuselage allow complete accessibility to engine from ground level. Internal fuel capacity 700 litres.

In 1948 Sikorsky received a contract for five Sikorsky S-55 utility helicopters for US Air Force evaluation under the designation YH-19 (49-2012 to 49-2016). The first of these flew on 10 November 1949 and was characterized by a blunt-ended fuselage, which lacked the broad, triangular fillet connecting the fuselage to the tail boom which distinguished all the later series aircraft. Another characteristic of the YH-19 was the horizontal stabilizer applied to the starboard side of the tail, which was replaced in the production aircraft by two anhedral tail surfaces. These was powered by a 550hp Wright R-1340-S1H2.

Sikorsky YH-19 49-2012

In 1951 the US Air Force purchased fifty-five H-19A production machines (51-3846/3895, -17662/17666), fitted with 447kW / 550hp Pratt & Whitney R-1340-57 engine as the prototypes. Some were converted to Air-Sea Rescue SH-19A and HH-19A after 1962.

Near the end of 1951 the Air Force accepted the first of an eventual 270 more powerful and slightly modified H-19B aircraft (51-3896/3968, 52-7479/7600, -10991/10994, 53-4404/4464, -4878/4885, 56-6673/6674), and at the same time loaned a single H-19A to the Army for operational evaluation in the utility transport and aeromedical evacuation roles.

Sikorsky H-19B 51-3961

The H-19B had a 522kW / 700hp Wright R-1340-3 engine and a larger diameter main rotor. The total included the SH-19B version for use as a transport aircraft. Many were converted to Air-Sea Rescue SH-19B and HH-19B with rescue hoists after 1962. Redesignated as UH-19B in 1962.

In the fall of 1951 the Army ordered the first batch of an eventual seventy-two H-19C aircraft (serials 51-14242 through -14313). The Army’s H-19C was essentially identical to the Air Force H-19A and, like that aircraft, was powered by a 600hp R-1340-57 engine and had two small fins fitted to the lower rear of the tailboom in an inverted ‘V’.

They were subsequently nicknamed “Chickasaw” and redesignated UH-19C in 1962. Both variants remained in Army service well into the mid-1960s.

In late 1952 orders were placed for the first of some 336 examples of the more capable H-19D variant (52-7601/7625, 54-1408/1437, 55-3176, -3183/3228, -4937/4944, -4462/4504, -5235/5240, 56-1519/1568, -4246/4283, 57-1616/1641, -2553/2558, -5926/5982), sixty-one of which were transferred to friendly nations under various military assistance programmes.

The H-19D was the Army’s version of the Air Force -B model and shared that aircraft’s more powerful 700hp engine, downward-sloping tailboom, repositioned horizontal tail fins, and smaller-diameter tail rotor. Redesignated UH-19D in 1962.

July 1952 saw the world’s first transatlantic helicopter crossing when two USAF H-19s traveled from the USA to Wiesbaden (Germany) with stops in Labrador, Greenland, Iceland, Scotland, and the Netherlands on their way. Total flight time was about 52 hours, but because of stops the trip took 21 days.

Versions of the S-55 were also acquired by the US Navy, which signed its first contract on 28 April 1950. Between August 1950 and January 1958, the US Navy received 119 helicopters, including ten HO4S-1 (125506 to 125515, equivalent to the H-19A) and 61 HO4S-2, redesignated as UH-19F in 1962 (based on the H-19B, 30 of these were built as HO4S-3G for the US Coast Guard (1252 to 1258, 1281, 1298 to 1310, and 1323 to 1331, redesignated as HH-19G in 1962).

Sikorsky HO4S-3G 1300

Seventy-nine HO4S-3 were built for the USN (133739 to 133753, 133777 to 133779, 138494 to 138529, and 138577 to 138601) and two US Army H-19B transfers (150193 to 150194).

The Marines troop and assault transport versions were designated HRS-1 and HRS-2 (99 built), similar to the HO4S-1, 151 of which were delivered from April 1952. Eighty-four HRS-3 helicopters with Wright R-1300-3 engines were also built.

The aircraft assigned to the SAR divisions of the MATS and US Army Aviation arrived in Korea in January 1953 with the 6th Transportation Company, whereas the Marines were able to test their HRS-1s for rapid assault operations which anticipated full-scale landing operations. MATS Air Rescue versions were designated SH-19B and became HH-19B.

Powered by a Pratt and Whitney engine of 600 h.p. or a Wright engine of 800 h.p., the H-19 has a “brochure” capacity of eight troops, six litters, or a maximum of 1,500 lb of cargo, which can be carried over a distance of some 100 miles at a conservative gross weight of 6,835 lb. The maximum useful load is 3,033 lb, which gives a range of 400 miles, or 1,000 miles with extra tankage. The normal cruising speed is 80 to 86 m.p.h., with a fuel consumption of 31 Imp. gal/hr.

In actual service, the H-19 could be relied upon to bring a mean of two tons into the front line for each hour that the aircraft was at work. Of the 20 aircraft assigned to a company, 12 (or 57 per cent) were normally available at any time.

During operational missions, the average daily flight time was four hours per aircraft, a quarter-hour more than in the service of New York Airways, who operated civil S-55s.

The employment of cargo helicopters in Korea was not, of course, limited to the U.S. Army; the Air Force and, in particular, the Marine Corps, have had such aircraft in that theatre for over two years. An especially notable operation was carried out by Army and Marine Corps’ helicopters flying side-by-side, in which over 6,000 neutral Indian troops were “trucked” from a carrier in Inchon harbour to the Parimunjoin area. The H-19s were limited to 1,000 lb per lift.

The helicopter requires approximately three hours of maintenance after one day’s work. Refuelling time is approximately five minutes.

The 1953 HRS was a USN transport helicopter version of the S-55. First production was sixty as HRS-1; 127783 to 127842. Minor equipment changes were in the HRS-2. 101 were built (129017 to 129049, and 130138 to 130205), of which several were converted to HRS-3 standards. They were redesignated as CH-19E in 1962.

The HRS-3 were powered by a Wright R-1300-2 engine. Twenty-seven were upgraded HRS-2, four were transferred from the USAF, and 103 production were built (130206 to 130264, 137836 to 137845, 140958 to 140961, 141029, 141230, 142430 to 142436, 144244 to 144258, 144268 to 144270, 144666 to 144668, 146298 to 146302, and 146439), of which sixteen went to Spain. They were redesignated as CH-19E in 1962.

The HRS-4 was a planned version for Wright R-1820 engines, none was built.

HRS-3

The 1,000th Sikorsky-built helicopter of the basic S-55 type was delivered to the US Marine Corps in mid-1956. The H-19 Chickasaw holds the distinction of being the Army’s first true transport helicopter and, as such, played an important role in the initial formulation of Army doctrine regarding air mobility and the battlefield employment of troop-carrying helicopters. The Chickasaw made its combat debut during the last stages of the Korean War, and went on to serve in Southeast Asia during the first years of the Vietnam War.

Various techniques and roles were first tested with the S-55 in Korea which were later to form the basis of new military doctrine, such as landing operations behind enemy lines, troop support, recovery of damaged vehicles and their capacity for counterattack and engagement. Another primary task of the helicopter was casualty evacuation or the rescuing of pilots who had come down behind the enemy lines. In the ambulance role, the S-55 could carry up to six stretchers, five of which could be hoisted on board using a mechanical winch fixed outside the cabin. The spacious cabin was designed to accommodate various seating arrangements or freight; it could take up to ten men or a load of approximately 1300kg.

Sikorsky S-55

The S-55 received American civil type approval on 25 March 1952 and the model with the Pratt & Whitney R-1340 engines became the S-55A, while the version with the Wright engine was designated S-55B.

On commercial versions with the R-1300 engine, the tailcone has been sloped down approximately 3.5 degrees to increase clearance of the main rotor in a rough landing.

The first S-55 in commercial use in the world went into service in British Columbia to build the Alcan project in Kitimat, where the building of power lines by helicopter was another first. In 1952, the helicopter became the first rotary wing craft to be used for commercial links in Europe; it was then flown by the Belgian airline Sabena between the chief towns in Belgium and Lille, Rotterdam, Bonn and Cologne, starting on 1 September.

Sabena S-55

For a time BEA ran regular services with two Sikorsky S-55 between London Airport at Hounslow, Middlesex, and Waterloo in the centre of the city.

BEA S-55

The Whirlwinds were equipped with exterior emergency floatation gear.

UH-19

The RCAF included six H-34 transports for service with No.108 Comunication flight in duties connected with construction of the Mid-Canada radar line on the 55th parallel.

RCAF No.108 Comunication flight H-34

Sikorsky manufactured a total of 1,281 S-55’s in ten years of continuous production commencing in 1949 and another 547 were built under license by Mitsubishi, Sud Aviation, and Westland. It was used by many military services including the RCAF (as the UH-19 and by the RCN (as the HO4S-3) on ‘plane guard’ duties with aircraft carriers.

Licence-production was undertaken by SNCA du Sud Est in France as the Sud-Est Elephant Joyeuse, in Japan by Mitsubishi, and by Westland in the UK, the latter developing versions with the Alvis Leonides Major piston engine and with the Bristol Siddeley Gnome turboshaft under the family name Whirlwind. 2.HIBM in Turkey assembled the H-19 Chickasaw under licence from Sikorsky during 1958.

When Westland began producing the S-55, it specified that the American engine would be used until a more suitable British powerplant was available. To meet this requirement, Alvis developed a double radial called the Leonides Major, which delivered 882hp derated to 750hp. The re-engined Whirlwind flew in 1955. It was followed in 1956 by the Mk.7 version intended to replace the old Fairey Gannet antisubmarine aircraft.

The Series 1 and 2, powered respectively by a Pratt & Whitney R-1340 or Wright R-1300 engine or the 755hp Alvis Leonides Major 755.
Installation of Wright R-1300 engines produced the Whirlwind Mk 3 in 1953, followed by the Mk 4 with new P&W R-1340 engines for use in the tropics; then Alvis Leonides Major engine.

The RAF also ordered this helicopter for transport and rescue missions: the Whirlwind HAR Mk.2 (the same as the naval version except for some differences in equipment) joined the Transport and Coastal Command Units from 1955. With Wright R.1300 engines, the Whirlwind Mk.3 went into production for the Royal Navy in 1953 and operated for many years from both ship and shore bases. The subsequent RAF HAR Mk.4 version was modified for use in the tropics and fitted with a new variant of the Pratt & Whitney R-1340. It was used in Malaysia.

WS.55 Whirlwind HAR.3

The turbine-powered S-55 made its first flight as the Whirlwind Series 3 in February 1959, powered by a General Electric T58 and introduced a new nose profile which offered better visibility. At the end of the year a Series 3 flew with a 1050shp Bristol Siddeley Gnorne free-turbine – the licence-built version of the T58. The new turboshaft engine was lighter and more powerful than the piston engine it superseded and offered improved performance and reliability.

The Royal Navy ordered a substantial number for anti-submarine duties under the designation Westland Whirlwind HAS.7. Deliveries began in May 1957.

Westland HAS.7

A total of sixty-eight new air-sea rescue HAR10 and transport HC10s were manufactured by Westland and a number of Whirlwind HAR2 and HAR4 piston-engined helicopters were subsequently re-engined.

Like the S-55, the Series 3 has a single door on the left side. The pilot and co-pilot sit above and behind the engine which places their cabin directly under the centreline of the main rotor. The rotor is hydraulically operated for both cyclic and collective pitch controls. Forward vision for landing was not ideal in earlier versions of the Whirlwind since the engine housing was in the nose. The turbine version was better since, though the nose was longer, it was at a more raked angle. Unlike the US turbine-powered S-55, the Whirlwind Series 3 has its engine exhaust on the left side almost immediately above the forward wheel, which can make cargo loading slightly hazardous if the engine is running or the exhaust hot. The turbine engine can be retrofitted to Series 1 and 2 machines.

Whirlwing HR.5

The first RAF unit to employ the HAR10 was No.225 Squadron, Transport Command, which became operational with the aircraft on 4 November 1961.

Used by the RAF in Europe, the Mediterranean and the Far East, the last squadron to be equipped with the aircraft Cyprus based No.84 Squadron converted to the Westland Wessex in March 1982.

Westland built a total of 364 S-55s under licence between 1953 and 1966, including 68 WS-55 civil aircraft. Most turbine-powered WS-55 Series 3s were converted from piston-engined Series 1s and 2s.

In 1964 Orlando Helicopter Airways Inc, of Sanford, Florida, was founded by Fred P. Clark to support, and in some cases, re-start production of Sikorsky helicopters no longer built by the parent company. In addition to a huge spares resource, Orlando Helicopters now holds the FAA type certificates for all H-19 and S-55 models. Several versions of the S-55 have since been developed by the firm. These include the OHA-S-55 Hen-Camper, a fully fitted out VIP version seating four passengers. New equipment includes a shower, wash-basin and toilet, air conditioning, carpeting and sound-proofing. An optional hydraulic winch, cargo sling or exterior spot-light can also be fitted. The Heli-Camper is powered by an overhauled and reconditioned 596kW Wright-Cyclone R-1300-3D engine.

The OHA-S-55 Nite-Writer is an unprecedented aerial advertising helicopter fitted with a 12.2m x 2.4m array of computer-controlled lights which can display messages and graphics, visible over a distance of 3.2km. More in demand is the OHA-S-55 Bearcat, for which Orlando has developed a quick-change hopper and spray system for crop and fertiliser spraying or seed spreading. Certified in 1991, the Bearcat is powered by a Pratt & Whitney R-1340 engine, which can run on automotive fuel, is fitted with a ‘quiet’ exhaust, and sold for US$300,000.

In October 1985 the company signed an agreement with China’s Guangzhou Machinery Tool Company to licence-build OHA-S-55 Bearcats. Under a 20-year joint venture Guangzhou Orlando Helicopters would first assemble American-built parts before progressing to manufacturing entire units. For carrying heavy external loads, such as logging or construction work, Orlando has developed the OHA-S-55 Heavy Lift which can deal with underslung weights of up to 1361kg. The company has also moved into a unique military market through modifying its S-55s for the US Army Missile Command. As QS-55 Aggressors they have been extensively modified to resemble Mil Mi-24 ‘Hind-E’s as flying targets. The Aggressors can be flown by a pilot or as drones (with dummy pilots in their cockpits) and have a new five-bladed main rotor, extensively redesigned nose, stub wings, and chaff and flare dispensers. A second, more aggressive military version is the armed OHA-AT 55 Defender, design of which began in 1990. Re-engined with a Garrett TPE331-3 turboshaft or a Wright R-1330-3 radial, the Defender also features a stub wing with pylons capable of carrying up to 500kg of weapons, and a five-bladed rotor. Capable of carrying up to 10 fully-equipped troops, the Defender can also be fitted out to accommodate six stretchers and two attendants.

In January 1971 Aviation Specialties Inc received certification for a turbine-powered conversion of Sikorsky S-55 helicopter powered with 1 x 840 hp AirResearch TSE-331, designated S-55-T. Aviation Specialties became Helitec Corporation in 1976.

Whisper Jet Inc produced a modified version of the S-55. The S-55QT is powered by a 650 shp Garrett Air Research TSE331-1OUA-511SW and fitted with a 5 blade main rotor head. Flown by a single pilot, the S-55QT can carry 9 passengers.

Gallery

Versions:

S-55:
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp

S-55A
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
Internal fuel capacity: 700 lt

S-55B.
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor dia: 16.15m
Internal fuel capacity: 700 lt
Cruise: 85 kts
Vne: 115 kts
Pax cap: 10
Crew: 2

S-55C
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp

YH-19
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp

H-19A
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
AUW 3,263kg
Crew: 2
Payload: 10 troops or six stretchers
Internal fuel capacity: 700 lt

H-19A
Engine: Pratt & Whitney R-1340-57, 600 hp
Rotors: 3-blade main; 2-blade tail
Rotor diameter: 49 ft.
Fuselage length: 41 ft 8.5 in
Loaded weight: 6,835 lb
Max speed: 105 mph
Ceiling: 12,900 ft
Typical range: 440 miles at 90 mph
Seats: 2 crew+13-10 passengers

H-19A / SH-19A
Engine: Pratt & Whitney R-1340-57, 600 hp
Rotors: 3-blade main; 2-blade tail
Rotor diameter: 53′ 3″
Fuselage length: 41 ft 8.5 in
Loaded weight: 6,835 lb
Max speed: 115 mph
Cruise: 90 mph
Ceiling: 12,900 ft
Typical range: 440 miles at 90 mph
Seats: 2 crew+13-10 passengersInternal fuel capacity: 700 lt

H-19B / SH-19B / UH-19B
1951
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor diameter 16.16m / 53’0″
Length: 12.88 m / 42’3″
Height: 4.06 m
Disc Area: 204.95 sq.m
Empty weight: 2381 kg
MAUW: 3583
Useful load: 2650 lb
Top Speed: 180 km/h / 112 mph
Cruise Speed: 146 km/h / 91 mph
Range: 579 km / 360 mi
Crew: 2
Payload: 10 troops or six stretchers.
Internal fuel capacity: 700 lt

H-19C / UH-19C
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
Maximum speed: 112 mph (180 km/h)
Empty weight: 5,250 lb (2381 kg)
Maximum weight: 7,900 lb (3583 kg)
Rotor diameter: 53 ft (16.2 m)
Fuselage length: 42 ft 3 in (12.9 m)
Overall height: 14 ft 8 in (4.5 m)
Crew: 2
Payload: 10 troops or six stretchers
Internal fuel capacity: 700 lt

H-19C / UH-19C
1952
Engine: 600hp R-1340-57
Useful load: 2705 lb
Max speed: 101 mpg
Cruise: 85 mph
Range: 450 mi
Ceiling: 10,500 ft

H-19D / UH-19D
1952
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor diameter: 53 ft (16.2 m)
Fuselage length: 42 ft 3 in (12.9 m)
Overall height: 14 ft 8 in (4.5 m)
Empty weight: 5,250 lb (2381 kg)
Maximum weight: 7,900 lb (3583 kg)
Useful load: 2650 lb
Maximum speed: 112 mph (180 km/h)
Cruise: 91 mph
Range: 385 mi
Ceiling: 12,500′
Crew: 2
Payload: 10 troops or six stretchers
Internal fuel capacity: 700 lt

HH 19 Chickasaw
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Length: 42.257 ft / 12.88 m
Rotor diameter: 52.986 ft / 16.15 m
Max take off weight: 7900.5 lb / 3583.0 kg
Weight empty: 5261.1 lb / 2386.0 kg
Max. speed: 97 kts / 180 km/h
Cruising speed: 79 kts / 146 km/h
Range: 313 nm / 580 km
Crew: 2
Payload: 10 Pax

HO4-1
U.S. Navy anti-submarine
Engine: Wright R-1820, 1,025 hp

HO4-2
U.S. Navy anti-submarine
Engine: Wright R-1820, 1,025 hp

HO4S
Engine: P&W R-1340-57
Main rotor: 53’3″
Length: 42’1″
Max speed: 115 mph

HO4S-1
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
AUW 3,263kg
Crew: 2
Internal fuel capacity: 700 lt

HO4S-2
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
AUW 3,263kg
Crew: 2
Payload: 10 troops or six stretchers
Internal fuel capacity: 700 lt

HO4S-2G
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp

HO4S-3 / UH-19F
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor diameter 16.16m
AUW 3,900kg
Vne: 115 kt
Crew: 2

HO4S-3G / HH-19G

HRS
Engine: P&W R-1340-57
Main rotor: 53’3″
Length: 42’1″
Max speed: 115 mph

HRS-1
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
AUW 3,263kg
Crew: 2
Payload: 8 troops
Internal fuel capacity: 700 lt

HRS-2
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp
AUW 3,263kg
Crew: 2
Payload: 8 troops
Internal fuel capacity: 700 lt

HRS-2
Engine: Pratt & Whitney R-1340 S3H2-57 Wasp, 550 hp
Rotor dia.: 53 ft
Weight: 6,835 lb
AUW 3,263kg
Max. Speed: 105 m.p.h.
Crew: 2
Payload: 10 troops
Internal fuel capacity: 700 lt

HRS-3 / CH-19E
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor diameter 16.16m
AUW 3,900kg
Crew: 2
Payload: 10 troops or six stretchers.

HRS-4
U.S. Marine assault transport
Engine: Wright R-1820, 1,025 hp

Westland Whirlwind H.A.R. Mk. 1
F.A.A.
Engine: Wright R-1340

Westland Whirlwind H.A.R. Mk. 2
R.A.F
Engine: Wright R-1340

Westland WS 55 Whirlwind HAR2
Engine: Bristol Siddeley Gnôme, 1036 shp

Westland WS-55 Whirlwind HAR.3
Engine: Wright R-1300-3 Cyclone radial, 596kW / 700 hp
Rotor diameter 58 ft
Fuselage length 41 ft 8.5 in
Mauw 7500 lb
Cruise speed 90 mph

Westland WS 55 Whirlwind Mk 4
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW / 550 hp

Westland WS 55 Whirlwind HAR4
Engine: Bristol Siddeley Gnôme, 1036 shp

Westland Whirlwind H.A.R. Mk. 5
F.A.A.
Engine: Alvis Lconides Major, 850 hp

Westland WS-55 Whirlwind HAS.7
Engine: 1 x Alvis Leonides Major Mk.155, 750 hp
Rotor diameter: 53 ft
Main rotor disc area: 2206 sq.ft
Main rotor: 3 blade
Fuselage length: 41 ft 8.5 in
Height: 13 ft 3 in
Empty weight: 5580 lb
MAUW: 7800 lb
Fuel capacity: 170 gal
Max speed: 109 mph at SL
Cruise speed: 86 mph
Service ceiling: 13,800 ft
Range: 400 mi
Tail rotor: 2 blade

Westland WS-55 Whirlwind HAR.9
Rotor diameter 58 ft
Fuselage length 41 ft 8.5 in
Mauw 7500 lb
Cruise speed 90 mph

Westland Whirlwind H.A.R. Mk. 21

Westland Whirlwind H.A.S. Mk. 22
Engine: Wright R-1820, 1,025 hp

Westland WS 55 Whirlwind HC10
Engine: Bristol Siddeley Gnôme, 1036 shp

Westland WS 55 Whirlwind HAR.10
Engine: Bristol Siddeley Gnôme, 1036 shp

Westland WS-55 Whirlwind HCC.12
Rotor diameter 58 ft
Fuselage length 41 ft 8.5 in
Mauw 7500 lb
Cruise speed 90 mph

Orlando Helicopter Airways OHA-S-55 Hen-Camper
Engine: 596kW Wright-Cyclone R-1300-3D
Passengers: 4

Orlando Helicopter Airways OHA-S-55 Nite-Writer

Orlando Helicopter Airways OHA-S-55 Bearcat
Engine: Pratt & Whitney R-1340 S3H2 Wasp radial, 447kW

Orlando Helicopter Airways OHA-S-55 Heavy Lift
Slung load: 1361kg

Orlando Helicopter Airways QS-55 Aggressors
Flying target
Main rotor: five-blade

Orlando Helicopter Airways OHA-AT 55 Defender
Engine: Garrett TPE331-3 turboshaft or Wright R-1330-3 radial
Main rotor: five-blade
Warload: 500kg
Passangers: 10 fully-equipped troops or six stretchers and two attendants.

Aviation Specialties S-55-T
Engine: 1 x 840 hp AirResearch TSE-331

Helitec Corporation S-55-T
1971
Engine: 1 x 840 hp AirResearch TSE-331-3U-303

S-55-GW
Engine: 700hp Wright R-1300

Whisper Jet Inc S-55QT
Engine: 650 shp Garrett Air Research TSE331-1OUA-511SW
Main rotor: 5 blade
Gross wt: 7700 lb
Service ceiling: 14,100ft
Max range: 365 miles
Max cruise: 98mph
Capacity: 9 passenger

Sud-Est Elephant Joyeuse

Sikorsky S-54

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After losing to Piasecki’s tandem-rotor configuration, Sikorsky bought back an R-4B from the US Air Force and modified it to the ‘sesqui-tandem’ configuration once tested on the VS-300, with an observer’s seat added aft of the main rotor. The resulting S-54 was first flown on 20 December 1948 and logged 4 hours 25 minutes flying time before being abandoned in early 1949.

Sikorsky considered that at cruising speed the tail rotor did not absorb any more power than that lost owing to rotor interference with twin rotors.

Sikorsky S-53 / HJS

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The Sikorsky S-53 was a development of the S-51 series and was designed specifically for utility, observation, and rescue duties aboard aircraft carriers, battleships, and cruisers.

The S-53 featured a fuselage and rotor system very similar to that of the S-51, but with some modifications: the tail rotor was raised above head-height for safety, the landing gear was strengthened for operations from a pitching deck, and the three-bladed main rotor was fitted with a folding mechanism. Amphibious landing gear was optional. A trapdoor in the cabin floor permitted the installation of a camera or a hoist for the transfer of bulky cargo by means of a sling.

The prototype, Bu. 30368, first flew on 22 September 1947.

Two prototypes of this three- to five-place aircraft were procured in 1948 by the U.S. Navy as the XHJS-1 (30368 and 30370), but no production contract resulted.

Additional attempts to market the S-53 were unsuccessful, and the model was developed no further.

XHJS-1
Engine: one 525hp Continental R-975-34
Rotor diameter: 49’0″
Max speed: 110 mph
Seats: 3-4

Sikorsky S-52 / HO5S / YH-18T / H-18

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Design work on the Sikorsky Model S-52 began in late 1945, and the craft made its first flight in the summer of the following year. The first American helicopter to be equipped with all-metal main and anti-torque rotor blades, the S-52 had a semi-monocoque, pod-and-boom type fuselage, a single 175hp Franklin engine, quadricycle wheeled landing gear, and a fully-enclosed cabin that could seat up to three people. The machine’s performance was impressive by the standards of the day. The commercial S-52 set three international speed and altitude records in 1948. These 1948 records were 208.57km/h over a 3-kilometer course, 197.55km/h over a 100-kilometer course, and 6468 metres absolute height.

A two-seat helicopter, featuring all-metal rotor blades. The two-seat S-52 (YH-18 Serial number 49-2888) first flew on Feb 12, 1947, powered by a 133kW Franklin engine.

Shortly after gaining the speed record, the little two-seater demonstrated its manoeuvrability, during the course of a routine test flight, by performing a series of successive “loops,” gaining height slightly after each in the approved manner. The pilot was Harry Thompson of Sikorsky’s flight-test department, and the date was May 9th, 1949. Later he repeated the performance – carrying Ralph Alex, then project engineer, as passenger.

The S-52’s performance was a factor in the Army’s 1949 decision to purchase four examples of the slightly modified Model S-52-2 for service test and evaluation. It is the H-18 that holds the distinction of being the first Sikorsky helicopter to be procured for service evaluation by the Army Ground Forces, as distinct from the USAAF.

The Army’s four YH-18As (serials 49-2888 through -2891) were essentially similar to the standard commercial S-52, differing primarily in their ability to carry a fourth passenger. Extensive testing showed the YH-18A to be quite capable in the light utility and observation roles, but the Army ultimately decided not to procure the type in quantity. Two were converted as XH-39/-39A test-beds.

Sikorsky H-18 Turbine version 49-2890

The S-52-2, a three/four-seater with a 183kW Franklin O-425-1 engine which was ordered by the US Marine Corps as a replacement for the HO3S. Deliveries of the HO5S-1 began in March 1952, and eight served also with the US Coast Guard as the HO5S-1G (1244 to 1251).

The use of a high-speed rotor allows a wide range of permissible rotor revolutions in flight, which is of particular advantage in the autorotative-landing case. Where an engine-off landing with zero forward speed is desired, it is possible, by using the kinetic energy stored in the rotor, to hover the machine momentarily in the flare-out before touching down. The touch-down itself is perfectly steady with the quadricycle landing gear.

The rotor blades were originally incorporated on the S-52-1 and the main spar is an alloy extrusion which is itself the leading edge of the blade. The trailing edge is made up in sections, each of which is attached to the spar individually. Thus the sections towards the blade tip are relieved of carrying the centrifugal load exerted on the inner sections, resulting in greater overall strength. The blades are fully interchangeable and their uniformity is a considerable contribution to the smoothness of the machine in flight.

S-52-2

The enlarged version, designated S-52-2, was granted its C.A.A. certification in the early part of 1951. A few civil machines were built, but the main production up to the present has been for the U.S. Navy; the type has been designated HO5S-1. Seventy-nine HO5S-1 went to the USN; 125516 to 125527, 126696 to 126705, 128601 to 128620, and 130101 to 130137. The machine is officially classified as a “three-place” helicopter but a fourth occupant can be carried on shorter flights. The large fuel-tankage capacity allows for 227 litres.

With a pilot and three passengers aboard sufficient fuel can be carried for a flight of approximately one-and-a-half hours – or a distance of between 193 kilometres and 225 kilometres at the cruising speed of 153km/h. With only three occupants the fuel tank may be filled, giving an endurance of 3.5 hours and a range, with fuel reserves, of 530 kilometers. This “built-in alternative” increases the machine’s versatility and has been proved to be of much practical value in the field. For delivery flights, auxiliary fuel tanks may be fitted to provide for a maximum distance of 1287 kilometres with pilot only aboard.

In its role as a rescue helicopter the S-52-2 normally carries two stretcher cases alongside the pilot. The canopy opens forward, in a manner reminiscent of the Bristol Freighter, to allow ease of loading and unloading.

Improvements in stability have been effected by the addition of large ventral stabilizing fins to the tail boom. These fins are fixed surfaces, as they have recently been so made on the American S-55. In earlier versions of the S-55 the fins were adjustable by the pilot to provide fore-and-aft trimming in flight, but this is no longer necessary. Additional vertical fin area has also been provided by an extended fairing on the tail-boom elbow to compensate for the increased keel surface forward of the rotor pylon with the longer nose.

The U.S. Navy purchased 89 S-52-3s as the HO5S-1 for general utility duties, all of which were delivered by 1953.

Sikorsky H-18 Turbine version 49-2890

One aircraft was later converted into the sole H-39 turbine-powered research helicopter and the S-52-2 eventually served the Navy, Marine Corps and Coast Guard as the HO5S.

In all its flight history, the S 52 3 only had one AD (Airworthiness Directive) released, relating to re torqueing of the flywheel bolts on the Franklin engine.

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 (Artoustc) turbine is now re-designated XH-39, and has set up an international helicopter speed record of 156 mph.

Sikorsky YH-1S

Gallery

Sikorsky YH-1S
Engine: 245 h.p. Franklin
Rotor dia: 33 ft
Weight: 2,400 lb
Max Speed: 110 mph

HO5S
Engine: Franklin O-425-1
Main rotor: 33’0″
Length: 28’4″
Max speed: 100 mph
Seats: 4

HO5S-1G
Engine: 1 x Franklin O-425-1, 183kW
Main rotor diameter: 10.06m
Fuselage length: 8.79m
Height: 2.64m
Max take-off weight: 1218kg
Empty weight: 744kg
Max speed: 177km/h
Cruising speed: 148km/h
Service ceiling: 4815m
Range: 576km
Crew + passengers: 1+3

S-52-2
Engine: Franklin 6V6-245-BI6F, 245 hp
Rotor diameter: 33 ft
Rotors: 3-blade main; 2-blade tail
Fuselage length: 27 ft 5 in
Loaded weight: 2,700 lb
Max speed: 110 mph
Ceiling: 22,200 ft
Typical range: 415 miles at 95 mph
Seats: 3-4

H-18
Engine: Franklin O-425-1, 245hp
Rotor diameter: 33’0″
Length: 28’10”
Useful load: 1050 lb
Max speed: 100 mph
Cruise speed: 92 mph
Range: 358 mi
Ceiling: 15,800′.
Seats: 4

Sikorsky S-52-2

Sikorsky VS-327 / R-5 / HO2S / S-51 / H-5 / Westland WS.51 Dragonfly / Widgeon

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S-51 / H-5 / HO3S

The development of the XR-5 officially began when the British Air Commission placed an order for two “large” (compared to the diminutive XR-4) prototype Vought-Sikorsky helicopters on April 29, 1942. At this time, German U-boat wolfpacks remained a considerable threat to the lifeline of trans-Atlantic convoys that sustained Great Britain. The convoys were particularly vulnerable in mid-Atlantic, beyond the range of shore-based anti-submarine patrol aircraft. There were also very few aircraft carriers available to sail with the convoys and provide air cover. A helicopter that could carry bombs or depth charges and operate from the decks of escort vessels or even merchant ships appeared to offer an ideal solution to the U-boat problem.

The US Army Air Forces caught on to the possibilities of an upgraded XR-4 and quickly submitted a request on May 8, 1942, for an upgraded design, a “workhorse” helicopter with a useful load of over 495 kg (1,100 lb). The request stated, “it is urgently desired to develop a helicopter with greater useful load, endurance, speed, service ceiling, which would have greater utility than the XR-4.” On May 27, the Air Material Command issued Technical Instruction 1124. This order released funds for the construction of four helicopters of the “workhorse” type, designated XR-5. The requirements of the AAF and the British were similar enough that a single design could probably fulfill both needs. Two of the four machines described in TI 1124 were earmarked for Britain to be paid for using Lend-Lease funds.

The XR-5 came about as a direct result of lessons learned from Sikorsky’s development of the R-4. While the R-4, and its developmental cousin, the R-6, saw operational service in World War II, they were underpowered, difficult to fly, and required excessive maintenance, which led to a limited service life. The production R-5s and their civilian counterpart, the S-51, overcame these difficulties and played an important role in establishing the helicopter as an indispensable aircraft for military and civilian operators.

The design process for the XR-5 was already well under way by the time TI 1124 was issued. More than six months earlier, Igor Sikorsky had anticipated a military request for a purpose-built observation helicopter. The Platt-LePage XR-1 had already won the AAF contract for development of an observation helicopter, but Sikorsky knew it would never become a practical service machine. Well ahead of actual events, he launched a program to develop a more practical design called the VS-327 (V for Vought and S for Sikorsky. Vought, like Sikorsky, was one of several companies owned by the holding company United Aircraft). Development began on September 26, 1941, and William E. Hunt was named project manager. When the Technical Instruction for the XR-5 was issued, the VS-327 handily met the requirements.

Work on the design progressed quickly, but when construction began on the first prototype, the pace slowed. As chief designer, Igor Sikorsky had a pivotal role to play but the demands of other projects distracted him. There was also considerable difficulty obtaining certain strategic materials such as aluminum to build the helicopter. The AAF considered helicopters interesting and promising, but gave conventional warplanes a higher priority. Sikorsky had to build certain sections of the helicopter, such as the tailcone and fuselage panels, from non-strategic materials, such as wood. This increased the aircraft’s weight, reduced structural integrity, and delayed the project. Aluminum versions replaced these wooden components when the predicted shortages failed to materialize. The 450hp Pratt & Whitney R-985 Wasp Junior engine chosen for the XR-5 was also a source of trouble. At that time, this power plant was used in Vought’s OS2U Kingfisher naval floatplane. To speed construction, Sikorsky retained the Kingfisher engine mount arrangement in the XR-5 but during ground runs, the helicopter overheated badly. A fan was needed to force more cooling air through the engine compartment, but there was not enough space to install it within the Kingfisher engine mount. Revising the mount and adding the fan further delayed the program.

Sikorsky was aware that the box-top fuselage of the XR-4 obstructed airflow from the main rotor and reduced the rotor’s lifting capacity. He also knew that visibility out of this earlier design could be much improved and these two design goals drove the overall layout of the XR-5. The fuselage was more streamlined and slimmer in profile, and nearly the entire nose of the helicopter was covered in Plexiglas windows. The observer occupied the front seat of this “fishbowl,” while the pilot occupied the seat directly behind him. The XR-4 used a tricycle undercarriage supplemented by a strut and wheel extending attached beneath the rear fuselage to prevent the tail rotor from striking the ground during flight-testing. Sikorsky dispensed with this wheel and strut on the production models.

Each of the three rotor blades resembled the fixed-wing of a conventional airplane. A laminated wooden spar supported wooden ribs and the whole assembly was covered with fabric. These blades were difficult to build, hard to balance, and easily damaged by rain. Sikorsky replaced the wooden spars with steel tubes in production versions of the XR-5 and this resulted in safer, more durable blades. However, he had to retain the fabric covering. It was not yet possible to build a rotor blade skinned with metal that was also flexible enough to flap and flex in flight. The S-51 had a three-blade rotor which had flapping and drag hinges and could be folded to facilitate storage. The early machines had manual control for the rotor pitch, later replaced by hydraulic servo-controls with power from a hydraulic pump driven by the tail transmission shaft.

Company chief test pilot Les Morris carried out the first flight of the XR-5 (s/n 43-28236) on August 18, 1943. Following adjustments to blade tracking and lead-lag dampers, flights soon exceeded 30 minutes. On September 13, the XR-5 lifted a pilot, observer, and eight passengers perched on the landing gear strut fairings, and exceeded the military useful load requirement by 270 kg (600 lb).

Testing progressed well until October 12. With Sikorsky’s nephew, Jimmy Viner, at the controls, the tail rotor failed at an altitude of 23 m (75 ft). Viner crash-landed and neither he, nor his observer were injured, but the aircraft suffered significant damage. Production on the next XR-5 (s/n 43-28237) was quickly stepped up and test flying resumed the last week of November 1943.

AAF leaders authorized series production of the XR-5 on March 24, 1943, to commence whenever the final development phase of the XR-5 was complete. This contract specified a production run of 250 aircraft, 100 of them earmarked for Great Britain. The contract soon increased by 150 helicopters for the AAF, and the Navy ordered 50 more. The development process had continued at a steady but relatively slow pace, as much of Sikorsky’s effort was focused on series production of the R-4 and R-6. These helicopters had met their contract requirements while the XR-5 was still struggling through the test program. Great Britain cancelled two XR-5s on March 25, 1944, because aircraft carriers and long-range patrol aircraft had filled the antisubmarine role originally envisioned for the R-5. The AAF quickly moved to take over this order, as Lt. Col. Frank Gregory, head of the AAF helicopter program, remained enthusiastic about XR-5. He considered it more advanced than any other American helicopter developed up to that time. Flight tests began on the fifth and final XR-5 at the Sikorsky plant in Bridgeport, CT, on January 17, 1944. The AAF accepted this aircraft and transferred it to Wright Field for further development on September 30, 1944.

That this dawn of a new technological era remained perilous for both man and machine is graphically illustrated by the fate of the XR-5s. The third (s/n 43-28238) was destroyed on November 4, 1944. The fabric covering one of the rotor blades tore loose and in the ensuing crash, the helicopter rolled over. The second XR-5 suffered a fatal crash at Gainesville, Florida, on December 2, 1944, when welds in one of the steel collars holding the blades to the rotor mast failed. As a result, a different welding technique was adopted on the assembly line. The first XR-5 suffered an engine failure while flying to a war bond rally in Nebraska. The pilot crash-landed but the airframe was too damaged to repair it was scavenged for spare parts. The AAF continued to test the last XR-5 (s/n 43-47954) until 1946, when the service handed the helicopter over to the National Air Museum (later the Smithsonian National Air and Space Museum).

By March 29, 1945, the AAF declared the XR-5 development program complete and service planners cleared the R-5A for series production. The AAF designated the first 26 aircraft off the line as YR-5A service test aircraft, but these helicopters did not otherwise differ from production R-5As. Two were assigned to the Navy under the designation HO2S-1 (75689 and 75690). In 1946 they were handed over to USCG as HO2S-1G. Trouble returned to the program after the R-5A began flying. Poor aerodynamic analysis by the National Advisory Committee for Aeronautics (NACA) caused Sikorsky to turn out unbalanced rotor blades, and the company was forced to correct the flaw with makeshift repairs that hurt performance of the production aircraft. When World War II ended, the AAF cancelled or reduced a number of aircraft contracts, including the R-5A, and Sikorsky completed 60 YR-5A and R-5A aircraft, of which, only nine were delivered before V-E Day. Ironically, the cancellation allowed the designer to further refine the aircraft, and to develop it for the civil market. This work produced the R-5F and its civilian counterpart, the S-51. In these models, the rear-seat cockpit was converted into seating for three and the observer seat became the pilot’s position.

Of the five XR-5, 43-28236/28239 to -47954, two were fitted with British equipment and redesignated as XR-5A.

Royal Navy Westland-Sikorsky S-51 Dragonfly – 1952

While production of the R-5A was getting under way (34 built, 43-46626 to -46659), five pre-series aircraft, 43-46611 to 46615, were converted into the R-5E, which had dual control. The YH-5E were redesignated as YH-5E in 1948. Twenty-one modified R-5As, 43-46606 and -46640 to -46659, were later given new, 600hp Wasp Junior engines and redesignated R-5D, then H-5D in 1948. The R-5D featured with nose wheel, rescue hoist, and external fuel tank. From the latter, the S-51 was developed, with a slightly enlarged four-seat cabin and a tricycle landing gear. The R-5A were fitted with external litters for SAR duty.

Sikorsky YR-5D 43-46642

Modified from a military design for the civil market (TC H-2), the S-51 was the world’s first commercial helicopter, inaugurated Philadelphia’s Helicopter Air Transport service. With a three-blade main rotor the S-51 first flew on 16 February 1946, and went to the USAF as R-5F, and USN as HO3S-1. Eleven of the 1948 R-5F were built, 47-480 to -490, basically a four-place military S-51 (with nose wheel). Licensed production in Great Britain as Westland-Sikorsky Dragonfly (with 520hp Alvis). The S-51 was a prototype for S-53.

Ninety-two of the 1946 HO3S-1 were built (57995 to 57998, 122508 to 122529, 122709 to 122728, 123118 to 123143, and 124334 to 124353). Nine HO3S-1s were used by the US Coast Guard as HO3S-1Gs (1230 to 1238). HO3S-1s served with distinction in the Korean War with Squadron HU-1. In 1950 Sikorsky built and tested a single XHO3S-3 with a redesigned rotor head and blades.

HO3S-2 was a designation reserved for a USN version of the H-5H but not used.

One HO3S-1 was fitted with a different rotor in 1950 as the XHO3S-3.

Although the AAF accepted R-5A helicopters before the end of World War II, these never reached operational units and service interest in the aircraft appeared to be waning. Sikorsky believed that without military customers, the civilian S-51 held the key to continued growth of the helicopter market and he promoted it vigorously.

On November 29, 1945, an S-51 dramatically rescued two seamen from a foundering barge off the coast at Bridgeport during severe weather. This event renewed military interest and a number of R-5 variants served until after the Korean War. Before the arrival of Bell’s H-13 (Model 47) into the Korean combat zone in 1951, military pilots flying the H-5 (H for helicopter replaced R for rotorcraft) conducted most of the thousands of medical evacuation (medevac) missions flown during that war. The H-5 and the H-13 reduced the fatality rate among wounded soldiers during the Korean War by more than 50 percent, however, the narrow center of gravity range on the H-5 soon made it obsolete compared to newer helicopters. Sikorsky attempted to extend the longevity of this classic design by offering the U. S. Navy a new five-seat version, the XHJS-1, but the helicopter lost out to Piasecki’s tandem-rotor HUP-1.

In 1950 Sikorsky built and tested a single XHO3S-3 with a redesigned rotor head and blades. The R-5B, R-5C and HO3S-2 were planned variants later cancelled.

8ikorsky H-5

Thirty-nine of the 1948 H-5G SAR version with hoist were built: 48-524 to -562.

Sixteen of the 1949 H-5H combination wheel and pontoon gear variant were built: 49-1996 to -2100.

Sikorsky H-5H

As the H-5 disappeared from the U.S. military inventories, Westland Aircraft Limited of England continued to build the aircraft, under license, as the HR.1 Dragonfly. These aircraft served with the Royal Air Force and Royal Navy throughout most of the 1950s. The British built version has a 520 hp Alvis Leonides radial engine installed with the crankshaft vertical, and having all metal rotor blades.

In December 1946 Westland Aircraft of Yeovil purchased a licence to build the S-51 in Britain. When they ceased production in 1953 they had built 139 machines. The Dragonfly, as the British-built machine was known, had a 520hp Alvis Leonides engine, a redesigned cabin for four passengers plus the pilot, and a three-blade rotor.

Basically similar to the US-built aircraft, the type was assembled from British-built components and in all but one variant was powered by the Alvis Leonides engine. The first civil Westland/ Sikorsky WS-51 was flown on 5 October 1948 and on 24 July 1951 the type became the first British-built helicopter to gain a certificate of airworthiness. Before that, in 1950, a version designated Dragonfly HR.Mk 1 equipped the Royal Navy’s first helicopter squadron, No. 705 formed at RNAS Gosport.

Pest Control Westland Sikorsky – 1949

Commercial versions are the Mk. 1A with Alvis Lconides and Mk. 1B with Wasp Junior engine, as in the American model. In the British services the type is known as the Dragonfly: the H.R. Mk. 1 (composite blades) and H.R. Mk. 3 (metal blades) are used by the Royal Navy; similar models in service with the R.A.F. are designated H.C. Mk. 2 and H.C. N1k. 4 respectively.

Westland WS.51 Dragonfly NR.1

Built to a total of 133, the Dragonfly was followed by a developed version, the Westland Widgeon, the prototype of which was a conversion of a Dragonfly to provide five-seat capacity and which benefited from the introduction of the improved rotor of the Sikorsky S-55. It had a four-blade main rotor with a 520hp Leonides 521 engine. The Widgeon original airframe was given a new front fuselage for a pilot and four passengers in a two/three arrangement, and small clamshell nose doors. The first Dragonfly converted to Widgeon standard, first flew on 23 August, 1955, for 30 minutes, at Yeovil, piloted by Roy Dradley.

During 1957, the five seat Widgeon obtained a Type Certificate of Airworthiness.

Westland produced 15 Widgeons and sold them to Ceylon, Jordan, Brazil and the Hong Kong police department. The Widgeon used an S-55 rotorhead which employs an offset flapping-hinge system, thus allowing more latitude in the centre of gravity and the position of cargo or passengers.

Westland sold their UK-built helicopters to Belgium, Ceylon, Egypt, France, Iraq, Italy, Japan, Thailand and Yugoslavia. At least one model was equipped for rescue operations with an external hoist capable of lifting up to 455kg. The bulk of these sales were for military use, but Belgium became a European pioneer in the civil field when Sabena bought three. The S-51 had a three-blade rotor which had flapping and drag hinges and could be folded to facilitate storage. The early machines had manual control for the rotor pitch, later replaced by hydraulic servo-controls with power from a hydraulic pump driven by the tail transmission shaft.

1949 London-Paris service, pilot Alan Bristow landing at Les Invalides
Westland Widgeon

B.E.A. commenced helicopter operations on 21 February 1949 with S-51s. BEA ran a trial helicopter service between Cardiff and Liverpool during 1950-51 and later, a service between Birmingham and London using the Sikorsky S-51.

BEA S-51

Helicopter Air Transport (HAT), based in New Jersey, became one of the first commercial helicopter operators when it took delivery of several S-51s in 1946. The operating cost of these aircraft proved too high for HAT’s primary business, flight training, and the company went bankrupt. A number of airlines and other companies experimented in the late 1940s and early 1950s with the S-51 for passenger, freight, and mail service but again, the costs of operating and maintaining the helicopter were simply too high for any of these enterprises too succeed. The S-51 failed to develop into a commercially viable aircraft but it proved that civilian helicopters could perform useful jobs, and it paved the way for more advanced designs. However, no helicopter airline has survived without massive government subsidies.

The S-51 has the distinction of being the first helicopter in the world to fly a regular service, and it did so in the United Kingdom. It flew in British European Airways’ colours between Liverpool and Cardiff in June 1950.

Gallery

Variants:

Dragonfly HR.Mk 1
Initial air/sea rescue (ASR) version for Royal Navy with the Alvis Leonides 50 radial engine

Dragonfly HC.Mk 2
Similar to Dragonfly HR.Mk 1 but equipped as casualty evacuation aircraft for the RAF

Dragonfly HR.Mk 3
Major production ASR version for Royal Navy (58 built); generally as Dragonfly HR.Mk 1 but introduced all-metal rotor

Dragonfly HC.Mk 4
Casualty evacuation version for RAF, similar to Dragonfly HR.Mk 3

Dragonfly HR.Mk 5
Final ASR version for Royal Navy, similar to Dragonfly HR.Mk 3

Westland/Sikorsky Mk 1A
Civil version with 388kW Alvis Leonides 521/1 engine; most used as civil transports, but small numbers to Japan for rescue, and to Italian and Thai air forces

Westland/Sikorsky Mk 1B
Civil version similar to Mk 1A but with 336kW Pratt & Whitney R-985-B4 Wasp Junior engine

Sikorsky XR-5 / VS-327
Rotor Diameter: 14.6 m (48 ft)
Length: 13.71 m (44 ft 11.5 in)
Height: 3.9 m (13 ft)
Weight empty: 1,656 kg (3,650 lb)

Sikorsky S-51 DragonFly (H-5)
Engine: One P&W R-985-AN-5 Wasp Junior, 450 hp / 336kW
Rotor diameter: 14.63 m
Length rotors turning: 13.70m
Fuselage length: 12.45 m
Height: 3.96 m
Weight: Empty: 1715 kg
Max take-off weight: 2263kg
Speed: Max: 171 km/h
Range: 579 km
Service Ceiling: 4389 m
Crew: 1
Passengers: 3

H-5
Engine: 450 h.p. Pratt & Whitney R985-5 or -7 Wasp Junior
Rotors: 3-blade main; 2-blade tail
Rotor dia.: 49 ft
Fuselage length: 44 ft 11.5 in
Loaded weight: 5,500 lb
Max. Speed: 103 mph
Ceiling: 13,500 ft
Typical range: 260 miles at 85 mph
Seats: 4

H-5E

H-5F

R-5F
Engine: 450hp P&W R-985-AN-5
Main rotor: 49’0″
Length: 41’1″
Seats: 4

H-5G

HO2S-1
Engine: 450hp P&W R-985-AN-5
Rotor: 48’0″
Length: 41’10’
Max speed: 93 mph

HO3S-1
Engine: 450 hp P&W R-985-AN-5
Rotor: 49’0″
Length: 41’1″
Max speed: 105 mph

Westland WS.51 Dragonfly HR.5
Engine: 520 hp Alvis Leonides radial
Main rotor diameter: 14.99m
Cruising speed: 142km/h

Westland WS.51 Dragonfly NR.1
Engine: 520 hp Alvis Leonides radial
Main rotor diameter: 14.99m
Cruising speed: 142km/h

Westland Widgeon
Engine: 520hp Leonides 521
Rotor dia: 49 ft 2 in
Length overall: 57 ft 7.5 in
Height: 12 ft 11.5 in
Empty weight; 4424 lb
MTOW: 5900 lb
Max payload: 1108 lb
Range max payload: 20 nm
Max range: 262 nm.
Max speed: 83 kt
Normal cruise: 70 kt
ROC: 970 fpm
Service ceiling: 10,500 ft
HIGE: 7500 ft
Seats: 5

Westland Widgeon 5
Engine; Alvis Leonides Major
Empty weight: 5262 lb
MAUW: 8000 lb
Max speed SL/ 95 kt
ROC: 825 fpm
Service ceiling: 12,500 ft
HIGE: 7,000 ft
Range: 300 nm
Max range; 1214 nm

Westland Dragonfly
Engine: 520 h.p. Alvis Leonides 50
Rotors: 3-blade main; 3-blade tail
Rotor diameter: 49 ft
Fuselage length: 57 ft 0.1 in
Loaded weight: 5,870 lb
Max speed: 103 mph
Ceiling: 14,200 ft
Typical range: 300 miles at 85 mph with full load
Seats: 4.

S-51
Westland Dragonfly

Sikorsky VS-316B Hoverfly II / R-6 / S-49

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The Sikorsky R-6 was developed parallel with the improved R-5. Ordered in 1943, the Sikorsky VS-316B or XR-6 prototype (43-47955) made its maiden flight on 15 October 1943. It was essentially a refined and developed version of the R-4, and the same rotor and transmission system was used in both types. A 225hp Lycoming O-435-7 engine provided the power, and the fuselage was transformed into a highly streamlined, metal-skinned unit with a one-piece moulded plexiglas cabin for the 2 crew members, and a four-wheel landing gear arrangement

First flown on Oct 15, 1943, Les Morris, was the Chief Test Pilot on the Sikorsky VS-300 starting in March, 1941 (and on the XR-4, XR-5 and XR-6 which followed).

On a March 1944 the XR-6 set new helicopter distance, endurance and altitude records when it made a non-stop flight of 623km from Washington, D.C, to Dayton, Ohio, in 4 hr. 55 min, climbing to 1524m over the Allegheny Mountains en route.

The XR-6 was followed by five 2-seat service test XR-6A’s for the USAAF (43-28240 to 28244) of which three, 46446 to 46448, went to the U.S. Navy (as XHOS-1), built by Sikorsky with 240hp Franklin O-405-9 engines.

Sikorsky XR-6A 43-28240

Twenty-six generally similar pre-production YR-6A’s, 43-45316 to 45341, were built by the Nash-Kelvinator Corporation under license from Sikorsky. Sikorsky Co, heavily involved in F4U production, contracted Kelvinator—then a licensee of Pratt & Whitney building airplane engines—to take over production of the R-6A. Redesignated as YH-6A in 1948. Kelvinator had an available plant in Detroit, and the tooling for the project was moved there. Kelvinator carried out the production of the one hundred and ninety-three R-6A’s (43-45342 to -45534) built from 1945. Thirty-six of these were delivered to the U.S. Navy as the HOS-1, 75589 to 75624 and 75729 to 75730, and formed the equipment of that service’s first helicopter squadron, which commissioned in July 1946. Twenty-seven were later were handed over to the USCG as HOS-1G. Those remaining in service in 1948 were redesignated as H-6A. One hundred and fifty went to the RAF in 1946 as Hoverfly II.

Forty R-6A’s were supplied to Britain under Lend-Lease, these being named Hoverfly II in British service. Fifteen of them were allocated to the Fleet Air Arm for communications and training in 1946; others served with No.657 (AOP) Squadron RAF and the Airborne Forces Experimental Establishment.

Like the R-4, the R-6 could be fitted with pontoons as an alternative to a wheeled landing gear, and was employed on a variety of duties including air/sea rescue, casualty evacuation and observation.

Beginning with the R-6, helicopters flown by the U.S. Coast Guard had Navy designations with the suffix letter G (as HOS-1G) until the 1962 redesignation of U.S. military aircraft.

Its career was, however, a short one: it was frequently beset by engine difficulties, and soon gave way to the more reliable R-5 and its derivatives. A proposed Lycoming-powered R-6B version by Nash-Kelvinator was cancelled.

Gallery

XR-6
Engine: Lycoming O-435-7, 225hp

R-6
Engine: One Lycoming O-405-9, 235 hp/168kW
Rotor diameter: 11.58 m
Length: 11.60 m
Height: 3.4 m
Max take-off weight: 1317kg
Empty weight: 923kg
Cruise Speed: 110 km/h
Max speed: 161km/h
Range: 565 km
Rate of climb: 4.0m/s
Service ceiling: 3050m
Passengers: 1
Crew: 1

R-6A / H-6A
Engine: Lycoming O-435
Main rotor: 38’0″
Length: 38’3″
Max speed: 96 mph

HOS
Engine: Franklin O-405-9
Main rotor: 38’0″
Length: 38’3″
Max speed: 105 mph

Sikorsky VS-316A / S-47 / R-4 Hoverfly / HNS / H-4

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R-4B

In 1941, the Vought Sikorsky Division of United Air¬craft was awarded a development contract for an experimental helicopter, designated XR 4. With an uncovered fuselage, it featured the first tail rotor configuration.

Sikorsky VS-316A / S-47 / R-4 Hoverfly Article

Designed by Igor Sikorsky and Michael Gluhareff, the prototype VS-316A first flew on 14 January 1942. The sole prototype (41-18874) was the first helicopter built expressly for military service (USAAF).

Sikorsky XR-4 41-18874

The XR-4 was delivered by air with Sikorsky along as a passenger. During the trip, they hovered low to read highway signs and once asked an astonished motorist for directions to the Army airfield. It arrived at Wright Field, Ohio, on 18 May 1942, having completed, in stages, the 1225km trip from Bridgeport, Connecticut, in 16 hr 10 min flying time.

It became XR-4C in 1943.

Sikorsky VS-316 NX28996

The Sikorsky R-4, or VS-316A, was a definitive development of Igor Sikorsky’s successful pre-war VS-300. Like the VS-300, it had a framework of heavy-gauge steel tube, and all but the extreme rear end of the fuselage was fabric-covered, as were the 10.97m diameter main rotor blades. It retained the single three-¬blade rotor and anti torque rotor of the VS 300, driven through transmission shafts and gearboxes. A completely new feature was the fully-enclosed cabin, with side-by-side seating and dual controls for the 2-man crew.

Sikorsky VS-316A

Les Morris, was the Chief Test Pilot on the Sikorsky VS-300 starting in March, 1941 (and on the XR-4, XR-5 and XR-6 which followed).

An experimental R-4 was fitted with a tilting tail rotor.

Later in 1942 an order was placed for three service test YR-4A’s (42-107234 to 107236) with 180hp R-550-1 engines and main rotors of 11.58m diameter, and similar changes were made to the XR-4 in 1943, after which it was redesignated XR-4C.

These were generally similar to the XR-4 except for an enlarged cabin, and were used inter alia for winterisation and tropical trials in Alaska and Burma. The first helicopter in the history of warfare were used during Operation Thursday, Burma, in 1944. They were Sikorsky R-4Bs. With a range of about 75 miles and cruise of 75 mph, they were used to transport wounded Chindits out of the stronghold.

Other 1943 developments included the first-ever landing by a helicopter on a ship at sea (by Colonel Frank Gregory on 7 May 1943) on the tanker Bunker Hill in Long Island Sound, USA, and the production of twenty-seven pre-series YR-4B’s for further evaluation by the USAAF, the U.S. Navy (three), U.S. Coast Guard (three) and the RAF (seven). The Navy designation was HNS.

RAF R-4 1945

Thirty production machines (YR-4As and YR-4Bs) were ordered in total.

In 1944 the R-4 became the first helicopter in the world to be placed in series production.

Twenty-seven YR-4B were produced, 42-107237/107248, 43-28223/28235, -28247, -47953, of which 3 to USCG and 7 to Great Britain as Hoverfly I. Additionally, 15 were produced for USN as HNS-1. They were fitted with bomb racks for anti-sub duty.

Three YR-4Bs and 22 R-4Bs were transferred from the USAAF as HNS-1 (39033 to 39052, 46445, 46699 to 46700, and 75727 to 75728).

Sikorsky YR-4B 42-107237

One hundred production R-4B’s were built, 43-46500 to 46599, similar to the YR-4B except for a more powerful engine; thirty-five were delivered to the USAAF for observation and liaison duties, and twenty to the U.S. Navy as HNS-1 reconnaissance and air/sea rescue aircraft. Twenty or twenty-two went to USCG as HNS-1 and 45 to RAF. The US Navy established its first helicopter squadron, VX-3, at Floyd Bennett Field NAS.

The YR-4B were redesignated as YH-4B in 1948.

HNS-1

The remaining forty-five were supplied to Great Britain under Lend-Lease, most of them going to the Royal Navy. The R-4B was known in British service as the Hoverfly I. In the RAF the Hoverfly I replaced the Rota (Cierva C.30A) autogiros of No.529 Squadron from August 1944, and some were supplied to the Helicopter Training School at Andover early in 1945. By the end of the year the type had passed out of RAF service, some aircraft being allocated for radar calibration work with the Telecommunications Research Establishment; others undertook snow and flood reporting duties, and one was allocated to the King’s Flight to carry mail and freight. The Joint Experimental Helicopter Unit, established in 1954, was equipped initially with R-4B and R-6A helicopters handed on from the Royal Air Force and Fleet Air Arm.

A U.S. Navy HNS-1 was flown by the Coast Guard, which was given responsibility for Navy helicopter development and operations during World War II. A float-equipped HNS-1 operated the icebreaker Northwind (AG-89) during Rear Admiral Richard E. Byrd’s 1947 expedition to the Antarctic.

USCG Northwind March 1947 Wellington New Zealand – Grumman J2F-6 Duck & Sikorsky HNS-1 BuNo 39043, the first helicopter to fly in New Zealand

It was not long before Sikorsky’s predictions about the lifesaving capabilities of the helicopter came true. U.S. Coast Guard Cdr. Frank Erickson flew the R-4 on the first helicopter mercy mission in January 1944, delivering blood plasma for injured sailors after an explosion occurred aboard a U.S. Navy destroyer outside of New York City’s harbor.

The first helicopter rescue during combat occurred in March 1944. Army Air Corps Lt. Carter Harman flew an R4 in Burma to rescue four men from behind enemy lines.

A Navy-Coast Guard HNS-1 was “stuffed” into a C-54 transport of the Air Transport Command at the Coast Guard air station in Brooklyn, N.Y. The helicopter was flown 1,000 miles on 29 April 1945, to Goose Bay, Labrador. It was then reassembled and rescued 11 Canadian airmen from two separate crashes in rugged territory, carrying them to safety one man per flight.

The first civilian helicopter rescue took place in November 1945, in Long Island Sound near Fairfield, Conn. An Army R-5 flown by Sikorsky pilot Viner rescued two men from an oil barge during a storm.
The R-4 did not enjoy a long service career, either in Britain or the United States, being supplanted in the early post-war years by the Sikorsky S-51 and its British-built equivalent, the Westland Dragonfly. Those still in American service were redesignated H-4B in 1948.

By the time production switched to the improved R-5/S-51 series, a total of 130 Sikorsky R-4s had been built.

VS-316A / XR-4
Engine: 165hp Warner R-500-3
Main rotor: 36’0″
Length: 35’5″
Max speed: 102 mph
Cruise: 85 mph

XR-4C
Engine: 180hp R-550-1

YR-4A
Engine: 180hp R-550-1
Main rotor: 38’0″
Length: 35’5″
Max speed: 75 mph

YR-4B / YH-4B 1943
Engine: 180hp R-550-1
Main rotor: 38’0″
Length: 48’2″
Useful load: 515 lb
Max speed: 75 mph
Range: 130 mi
Ceiling: 8,000′

R-4B / H-4B
Engine: Warner R.550-3, 180 hp / 134kW
Rotor dia: 38 ft (11.58 m)
Fuselage length: 10.35 m
Length: 48 ft 2 in (14.68 m)
Height: 12 ft 5 in (3.78 m)
Empty weight: 952kg
Max TO wt: 2535 lb (1150 kg)
Max level speed: 75 mph (121 kph)
Max speed @ 1150 kg: 65 kts
Rate of climb: 3.3m/s
Seats: 2

HNS
Engine 180hp Warner R-550-3
Main rotor: 38’0″
Length: 35’5″
Max speed: 77 mph

Sikorsky VS.300

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Sikorsky VS-300 NX28996 on tether

Russian-born Igor Sikorsky built his first helicopter, powered by a 25hp Anzani engine, in 1909. It would not leave the ground, and a second machine, completed in 1910, was little better; it did rise a short distance, but was incapable of lifting a pilot, and Sikorsky turned his attention to fixed-wing aeroplanes. After the 1917 Revolution he left the country, settling in the United States some two years later, and soon entering the aircraft industry of his new country.

As the era of flying boats faded, lgor Sikorsky revived the idea of developing the helicopter. Once again he was involved in “advanced pioneering work . . . where extremely little reliable information and no piloting experience whatever were available.” By the late 1930s changing requirements for military and commercial air transport forecast the termination of the large flying boat, and Sikorsky returned to his first love, the helicopter. The essential aerodynamic theory and construction techniques that had been lacking in 1910, however, were now available. In a memo to the general manager of Vought-Sikorsky (the new name of the company) dated Aug. 10, 1938, he wrote:

“Besides having considerable possibilities as a privately owned aircraft, the direct-lift ship [helicopter] will be a very important service type for the army and navy. For the army, this type of ship would render excellent services for communication, fire control, short-range reconnoitering and bombing operations. For the navy, the ship would be extremely useful as the only aircraft that could take off and land without catapulting from any surface vessel….”

Even though an official manufacturing order had not been issued to begin work on a “new” type of aircraft, helicopter development continued throughout the fall of 1938. lgor Sikorsky and a handful of engineers and production personnel spent lunch breaks and off hours sketching, designing, fabricating and testing various components and systems for what would become known as the VS-300 (“V’ for Vought, “S” for Sikorsky and “300” for Sikorsky’s third helicopter design).

Rotor tests were encouraging enough for Sikorsky to request a meeting with Eugene Wilson, a senior vice president of United Aircraft, at which he received the go-ahead to construct a prototype helicopter. Sikorsky’s argument for building the rotorcraft had been compelling.

“So important is this development to the future of society that it becomes our responsibility to undertake it. While admittedly radical, and possibly ‘impossible,’ the helicopter is wholly rational. Like no other vehicle, it will operate without regard to prepared landing surfaces. Thus, it will free us of the serious handicap to progress imposed by fixed-wing aircraft-airport limitations. It is not competitive with the airplane, but complementary to it. If Sikorsky does not create this craft of the future, another [company] will. By training and expedence, we are best equipped to do it. And finally, unlike the airplane, the helicopter will be used not to destroy but to save lives!”

Early in 1939, with a well trained engineering group at his disposal, he started the construction of the VS-300 helicopter. As he said later, “There was a great satisfaction in knowing that, within a short period of time, good engineering along a novel line produced encouraging results.”

Sikorsky VS-300 First flight

On September 14, 1939, the plane lifted off the ground on its first flight. Its designer was at the controls; during his entire career Sikorsky always insisted on making the first trial flight of any new design himself. At this stage the aircraft was still tethered to the ground and had weights suspended underneath it to help keep it stable.

It was powered by a 4-cylinder Franklin engine of 75hp, had full cyclic pitch control for the 28’0″ three-blade main rotor and a single anti-torque tail rotor at the end of a narrow enclosed tailboom which also supported a large under-fin.

The VS-300 had a three-bladed main rotor, 28 ft / 8.53 m in diameter, a welded tubular steel frame; a power transmission consisting of V-belts and bevel gears; a two-wheel landing gear arrangement and a completely open pilot’s seat. A single foot pedal controlled the antitorque tail rotor.

The cyclic control was not fully satisfactory, however, and by the time the VS-300 made its first free flight on 13 May 1940, 3 feet off the ground for 10 sec with 35 foot long ropes. By now powered by a 90hp Franklin motor, the configuration had changed to an open-framework steel-tube fuselage with outriggers at the tail end. Each of these mounted a horizontally-rotating airscrew to provide better lateral control; the vertical tail screw was retained. Sikorsky tried 19 different configurations before he was satisfied with the final design of the VS-300.

By mid-1940 the VS-300 was staying airborne for 15 min. at a time. Various modifications were made during 1940-41 with three tail rotors, and the replacement of the tail outriggers in June 1941 by a short vertical pylon carrying a single horizontal tail rotor, and the reinstatement in December of a now fully satisfactory cyclic pitch control for the main rotor. Other alterations concerned the arrangement of the main undercarriage and the fitting of nose and tail wheels in place of skids.

On July 18, 1940, a 15-min. flight was made during which the ship hovered. On Jan. 10, 1941, the VS-300 made a flight that lasted more than 25 min., which was believed to be the longest flight ever made by a helicopter in America at that time.

During 1940, Sikorsky removed the cyclic pitch control, which varies the pitch angle of each blade as it rotates so that the helicopter can be manoeuvred, and substituted two small horizontal ro¬tors on outriggers for pitch and lateral control. The modifications proved successful, and on May 6, 1941, this version of the VS 300 had surpassed the Focke ¬Achgelis’s duration record with a flight of 1 hr. 32 min. 26.1 sec. Able to climb vertically, fly sideways and backward, it could not safely fly forward until 1941. For publicity photos, mechanics changed wheels on the hovering VS300A.

Les Morris, was the Chief Test Pilot on the Sikorsky VS-300 starting in March, 1941 (and on the XR-4, XR-5 and XR-6 which followed).

On Apr. 17, 1941, the VS-300 recorded another first by making the world’s initial helicopter water landings by fitting pneumatic flotation bags under the main undercarriage wheels.

Sikorsky VS-300A NX28996

In its final form the VS-300 had a 150hp Franklin engine, a fabric-covered fuselage and a tricycle undercarriage.

During its lifetime, the VS-300 logged more than 100 hr. of flight time and demonstrated the concepts and principles that were later utilized in the design of the Sikorsky R-1, the worlds first production helicopter.

In 1943 the VS-300 was delivered to the Henry Ford Museum in Dearborn, Michigan, where it is still housed.

The general manager of Sikorsky Aircraft, Lee S. Johnson, summed up its contribution twenty years later when he said: ‘Before Igor Sikorsky flew the VS-300, there was no helicopter industry; after he flew it, there was.”

VS-300
Engine: 75hp Franklin
Rotor: 28’0″ three-blade
Seats: 1

VS-300A
Engine 90hp Franklin

Sikorsky 1909 Helicopter

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In Kiev in May of 1909 Igor Sikorsky began construction of a helicopter. Its failure revealed some of the practical obstacles. Powered by a three-cylinder, 25-hp Anzani engine that drove coaxial, twin blade rotors, the H-1 shook wildly but did not have enough power to lift itself off of the ground. A second machine with a larger engine was tested in 1910, but also failed to fly. He then made a major decision: “I had learned enough to recognize that with the existing state of the art, engines, materials, and-most of all-the shortage of money and lack of experience … I would not be able to produce a successful helicopter at that time.” In fact, he had to wait 30 years before all conditions could be met.

Sikorsky

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Igor Sikorsky
Sikorsky Aero Engineering Corporation

lgor Ivan Sikorsky was born in Kiev, Ukraine, on May 25, 1889. His father was a graduate physician and professor of psychology. His mother also was a physician but never practiced professionally. Her interest in art and in the life and work of Leonardo da Vinci stimulated her son’s early interest in model flying machines; when he was 12 years old he made a small rubber-powered helicopter that could rise in the air.

Sikorsky Article

In 1903 Sikorsky entered the Naval Academy in St. Petersburg, with the intention of becoming a career officer, but his interest in engineering led to his resignation from the service in 1906. After a brief period of engineering study in Paris, he returned to Kiev and entered the Kiev Polytechnic Institute. Following a reasonably successful academic year, however, he concluded that the abstract sciences and higher mathematics as then taught had little relationship to the solution of practical problems, and he left the school, preferring to spend his time in his own shop and laboratory.

A trip through Europe in the summer of 1908 brought him into contact with the accomplishments of the Wright brothers and the group of European inventors who were trying to match their progress in flight. Returning to Kiev, Sikorsky came to the conclusion that the way to fly was “straight up,” as Leonardo da Vinci had proposed, a concept that called for a horizontal rotor. Assisted financially by his sister Olga, he returned to Paris in January 1909 for further study and to purchase a light-weight engine.

Back in Kiev in May of 1909 he began construction of a helicopter, the H-1. Its failure revealed some of the practical obstacles. Powered by a three-cylinder, 25-hp Anzani engine that drove coaxial, twin blade rotors, the H-1 shook wildly but did not have enough power to lift itself off of the ground. A second machine with a larger engine was tested in 1910, but also failed to fly. He then made a major decision: “I had learned enough to recognize that with the existing state of the art, engines, materials, and-most of all-the shortage of money and lack of experience … I would not be able to produce a successful helicopter at that time.” In fact, he had to wait 30 years before all conditions could be met.

For the time being Sikorsky decided to enter the field of fixed-wing design and began construction of his first airplane. His S-1 biplane was tested early in 1910, and, although its 15-horsepower engine proved inadequate, a redesigned airframe with a larger engine (S-2) carried him on his first short flight. The S-3, S-4, and S-5 followed in quick succession, each a refinement of its predecessor, and each adding to his piloting experience. Finally, by the summer of 1911, in an S-5 with a 50-horsepower engine, he was able to remain in the air for more than an hour, attain altitudes of 1,500 feet (450 metres), and make short cross-country flights. This success earned him International Pilot’s License Number 64.

The subsequent S-6 series established Sikorsky as a serious competitor for supplying aircraft to the Russian Army. Characteristically, he soon took a giant step: the first four-engined airplane, called “Le Grand,” the precursor of many modern bombers and commercial transports, which he built and flew successfully by 1913. Among its innovative features, not adopted elsewhere until the middle 1920s, was a completely enclosed cabin for pilots and passengers.

Although he was now an internationally known aircraft designer and pilot, Sikorsky decided to leave Russia for France in 1918 following the Bolshevik Revolution. On Mar. 30, 1919, Sikorsky came to New York City to begin his career anew. Initially unable to land a job with a U.S. airplane manufacturer, Sikorsky supported himself by teaching mathematics to Russian emigees in New York and giving lectures on aviation and astronomy until Mar. 5, 1923, when he received enough financing to launch the Sikorsky Aero Engineering Corp.

They set up shop in an old barn on a farm near Roosevelt Field on Long Island. Sikorsky became a U.S. citizen in 1928. From 1925 to 1926, the company produced one-of-a-kind, fixed-wing designs built to customer needs. In 1924, using junkyard parts and war-surplus materials, Sikorsky constructed his first S-29A, a twin-engine, 14 passenger design. By 1929 the company, having become a division of United Aircraft Corporation, occupied a large modern plant at Bridgeport, Connecticut, and was producing S-38 twin-engined amphibians in considerable numbers. In 1931 the first S-40, the “American Clipper,” pioneered Pan American World Airways mail and passenger routes around the Caribbean and to South America. By the summer of 1937 Pan American began transpacific and transatlantic service with the first four-engined S-42 “Clipper III” the last of the Sikorsky series, the ancestor of which had been “Le Grand” of 1913.

As the era of flying boats faded, lgor Sikorsky revived the idea of developing the helicopter. Once again he was involved in “advanced pioneering work . . . where extremely little reliable information and no piloting experience whatever were available.” By the late 1930s changing requirements for military and commercial air transport forecast the termination of the large flying boat, and Sikorsky returned to his first love, the helicopter. The essential aerodynamic theory and construction techniques that had been lacking in 1910, however, were now available. In a memo to the general manager of Vought-Sikorsky (the new name of the company) dated Aug. 10, 1938, he wrote:

“Besides having considerable possibilities as a privately owned aircraft, the direct-lift ship [helicopter] will be a very important service type for the army and navy. For the army, this type of ship would render excellent services for communication, fire control, short-range reconnoitering and bombing operations. For the navy, the ship would be extremely useful as the only aircraft that could take off and land without catapulting from any surface vessel….”

Even though an official manufacturing order had not been issued to begin work on a “new” type of aircraft, helicopter development continued throughout the fall of 1938. lgor Sikorsky and a handful of engineers and production personnel spent lunch breaks and off hours sketching, designing, fabricating and testing various components and systems for what would become known as the VS-300 (“V’ for Vought, “S” for Sikorsky and “300” for Sikorsky’s third helicopter design).

Rotor tests were encouraging enough for Sikorsky to request a meeting with Eugene Wilson, a senior vice president of United Aircraft, at which he received the go-ahead to construct a prototype helicopter. Sikorsky’s argument for building the rotorcraft had been compelling.

“So important is this development to the future of society that it becomes our responsibility to undertake it. While admittedly radical, and possibly ‘impossible,’ the helicopter is wholly rational. Like no other vehicle, it will operate without regard to prepared landing surfaces. Thus, it will free us of the serious handicap to progress imposed by fixed-wing aircraft-airport limitations. It is not competitive with the airplane, but complementary to it. If Sikorsky does not create this craft of the future, another [company] will. By training and expedence, we are best equipped to do it. And finally, unlike the airplane, the helicopter will be used not to destroy but to save lives!”

Early in 1939, with a well trained engineering group at his disposal, he started the construction of the VS-300 helicopter. As he said later, “There was a great satisfaction in knowing that, within a short period of time, good engineering along a novel line produced encouraging results.” On September 14, 1939, the plane lifted off the ground on its first flight. Its designer was at the controls; during his entire career Sikorsky always insisted on making the first trial flight of any new design himself. On May 6, 1941, in an improved machine, he established an international endurance record of 1 hour, 32.4 seconds.

Sikorsky regarded it as a useful tool for industry and air commerce but primarily as an effective device for rescue and relief of human beings caught in natural disasters, such as fire, flood, or famine. He estimated that over 50,000 lives had been saved by helicopters.

lgor Sikorsky only complained that of all his past predictions, those that he lived to regret were on the “too conservative” side.

Sikorsky retired as engineering manager tor his company in 1957 but remained active as a consultant until his death on October 26, 1972, at Easton, Connecticut. In addition to his wife (married in 1924), he left one daughter and four sons, all of whom have professional careers. Sikorsky received many honorary doctorates in science and engineering, honorary fellowships in leading scientific and technical societies in the United States and Europe, and the highest medals and awards in aviation, including the Cross of St. V1adimir from Russia; the Sylvanus Albert Reed Award for 1942 from the Institute of Aeronautical Sciences in New York; the United States Presidential Certificate of Merit in 1948; the Daniel Guggenheim Medal and Certificate for 1951; the Elmer A. Sperry Award for 1964; and the National Defense Award in 1971.

Apparently, when he checked in for a Sabena S-58 flight, Igor Sikorsky was asked if his name was spelt like the helicopter’s.

Dean C. Borgrnan, who took over as president and CEO of Sikorsky Aircraft in October 1998, said: “As we approach a new millennium, a new generation of helicopter pioneers is designing and building aircraft that will revolutionize the industry. The S-92 and the RAH-66 represent two of the most advanced helicopters in the world today. Technical achievements from these two programs are being incorporated on the Black Hawk and its derivatives.”

Sikorsky also was retooling its design and engineering computers. Sikorsky selected IBM and Dassault Systemes to provide the Enovia PM (Product Manager) solution as its enterprise~wide computer system.

1923: (Igor I) Sikorsky Aero Engr Corp.

1925: Sikorsky Mfg Co, Bridgeport CT (company funded in part by composer-pianist Sergei Rachmaninoff).

1926: Leased former L-W-F plant, College Point, Long Island NY.

1928: Sikorsky Aviation Div, United Aircraft & Transport Corp, Bridgeport.

1939: (Chance) Vought-Sikorsky Div, United Aircraft Corp.

1943: Sikorsky Aircraft Div, United Aircraft Corp.

1975: Sikorsky Aircraft Div, United Technologies Corp, Stratford CT.

199?: Sikorsky Aircraft Corp, United Technologies Corp

Sikorsky was sold to Lockheed Martin in 2015