Sikorsky S-55

The Sikorsky H-19 Chickasaw, (also known by its Sikorsky model number, S-55) was a multi-purpose helicopter used by the United States Army and United States Air Force. It was also license-built by Westland Aircraft as the Westland Whirlwind in the United Kingdom. United States Navy and United States Coast Guard models were designated HO4S, while those of the U.S. Marine Corps were designated HRS. In 1962, the U.S. Navy, U.S. Coast Guard and U.S. Marine Corps versions were all redesignated as H-19s like their U.S. Army and U.S. Air Force counterparts.

Design and development

Template:Expand section The H-19's first flight was on November 10, 1949 and it entered operations in 1950. Over 1,000 of the helicopters were manufactured by Sikorsky for the United States. An additional 550 were manufactured by licensees of the helicopter including Westland Aircraft, the Société nationale des constructions aéronautiques du sud-est (SNCASE) in France and Mitsubishi in Japan.

The helicopter was widely exported, used by many other nations, including Portugal, Greece, Israel, Chile, South Africa, Denmark and Turkey.

File:Mi-4.jpg

Mil Mi-4 at Prague Aviation Museum shows resemblance

The Soviet Mi-4 was a direct response to the American H-19 Chickasaw which it resembled in layout. While the Mi-4 superficially resembles the H-19 Chickasaw, it is a larger helicopter and is able to lift more weight. The first model entered service in 1952. Its successor, the Mi-8 would become the world's most-produced helicopter.

Operational history

The H-19 Chickasaw holds the distinction of being the US 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 H-19 underwent live service tests in the hands of the 6th Transportation Company, during the Korean War beginning in 1951 as an unarmed transport helicopter. Undergoing tests such as medical evacuation, tactical control and front-line cargo support, the helicopter succeeded admirably in surpassing the capabilities of the H-5 Dragonfly which had been used throughout the war by the Army.

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UH-19B at the Milestones of Flight Museum, Fox Field, Lancaster, California

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A Sikorsky S-55B in service with Golden West Helicopters, St. Albert, Alberta, 1985

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Sikorsky UH-19 at the Canadian Museum of Flight 1988.The aircraft is painted as it would have looked while working on the construction of the Mid-Canada Line

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UH-19B, USAF Museum

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A U.S. Navy HO4S of HS-4 taking off from USS Badoeng Strait in 1954

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A USMC HRS-2 of HMR-161 in Korea, 1953

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An HO4S of the Royal Canadian Navy

The U.S. Air Force ordered 50 H-19A’s for rescue duties in 1951. These aircraft were the primary rescue and medical evacuation helicopters for the USAF during the Korean War. The Air Force continued to use the H-19 through the 1960s, ultimately acquiring 270 of the H-19B model.

France made aggressive use of helicopters in Algeria, both as troop transports and gunships, Piasecki/Vertol H-21 and Sud-built Sikorski H-34 helicopters rapidly displaced fixed-wing aircraft for the transport of paras and quick-reaction commando teams. In Indochina, a small number of Hiller H-23s and Sikorsky H-19s were available for casualty evacuation. In 1956, the French Air Force experimented with arming the H-19, then being superseded in service by the more capable Piasecki H-21 and Sikorsky H-34 helicopters. The H-19 was originally fitted with a 20-mm cannon, two rocket launchers, plus a 20-mm cannon, two 12.7-mm machine guns, and a 7.5-mm light machine gun firing from the cabin windows, but this load proved far too heavy, and even lightly-armed H-19 gunships fitted with flexible machine guns for self-defense proved underpowered.

The H-19 was also used in the early days of the Vietnam War before being supplanted by the Sikorsky H-34 Choctaw, which was based on the H-19.

Variants

YH-19

Five early production S-55s for evaluation.

H-19A

USAF version of the YH-19 powered by a 600 hp, (472 kW) R-1340-57 engine, redeisgnated UH-19A in 1962, 50 built.

SH-19A

H-19As modified for air-sea rescue, redesignated HH-19A in 1962.

H-19B

H-19A with a more powerful 700 hp, (522 kW) R-1300-3 engine, redesignated UH-19B in 1962, 264 built.

SH-19B

H-19Bs modified for air-sea rescue, redesignated HH-19B in 1962.

H-19C

US Army version of the H-19A, redesignated UH-19C in 1962, 72 built.

H-19D

US Army version of the H-19B, redesignated UH-19D in 1962, 301 built.

HO4S-1

US Navy version of the H-19A, 10 built.

HO4S-2

Project for rescue version for the United States Coast Guard, not built.

HO4S-3

Re-engined US Navy & Canadian version with 700 hp, (522 kW) Wright R-1300 engine, redesignated UH-19F (American variant) H04S-3 (Canadian variant) in 1962, 79 built.

HO4S-3G

United States Coast Guard version of the HO4S-3, redesignated HH-19G in 1962, 30 built.

HRS-1

United States Marine Corps version of the HO4S for eight troops, 60 built.

HRS-2

HRS-1 with equipment changes, 101 built.

HRS-3

HRS-2 with a 700 hp, (522 kW) R-1300-3 engine, became CH-19E in 1962, 105 built and conversions from HRS-2.

HRS-4

Project for HRS-3 with a 1,025 hp, (764 kW) R-1820 radial engine, not built.

UH-19A

H-19A redesignated in 1962.

HH-19A

SH-19A redesignated in 1962.

UH-19B

H-19B redesignated in 1962.

HH-19B

SH-19B redesignated in 1962.

CH-19E

HRS-3 redesignated in 1962.

UH-19F

HO4S-3 redesignated in 1962.

HH-19G

HO4S-3G redesignated in 1962

S-55

Commercial version with 600 hp, (472 kW) R-1340 engine.

S-55A

Commercial version with 800 hp, (596 kW) R-1300-3 engine.

S-55C

S-55A with a 600 hp, (472 kW) R-1340 engine.

S-55T

aircraft modified by Aviation Specialties and produced and marketed by Helitec with a 650 shp, (485 kW) Garrett AiResearch TPE-331-3U-303 turboshaft and updated equipment.

S-55QT

Commercial conversion. Ultra-quiet helicopter for sight-seeing flights over the Grand Canyon.

OHA-S-55 Heli-Camper

Commercial conversions carried out by Orlando Helicopters.

OHA-S-55 Nite-Writer

Commercial conversion. Aerial advertising helicopter, fitted with a 12.2-m x (40-ft x 8-ft) array of computer-controlled lights.

OHA-S-55 Bearcat

Commercial conversion. Agricultural helicopter.

OHA-S-55 Heavy Lift

Commercial conversion. Flying crane helicopter.

QS-55 Aggressors

Commercial conversion. S-55 helicopters converted into flying targets.

OHA-AT-55 Defender

Commercial conversion. Armed military helicopter.

Whirlwind HAR21

HRS-2 for Royal Navy, ten delivered.

Whirlwind HAS22

H04S-3 for Royal Navy, 15 delivered.

Later marks of Whirlwind were built under licence.

Operators

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Specifications (H-19)

H-19 at National Museum of the United States Air Force, showing unusual mounting of engine

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UH-19B rotor head

General characteristics

• Crew: 2 (pilot, copilot)
• Capacity: 12 troops or 8 litters
• Length: 62 ft 7 in (19.1 m)
• Rotor diameter: 53 ft (16.16 m)
• Height: 13 ft 4 in (4.07 m)
• Disc area: ft² (m²)
• Empty weight: 4,795 lb (2,177 kg)
• Loaded weight: 7,200 lb (3,266 kg)
• Max takeoff weight: 7,900 lb (3,587 kg)
• Powerplant: 1× Pratt & Whitney R-1340-57 radial engine, 600 hp (450 kW)

Performance

• Maximum speed: 101 mph (163 km/h)
• Range: 405 mi (652 km)
• Service ceiling: 10,500 ft (3,200 m)
• Rate of climb: 700 ft/min (213 m/min)

See also

Related development

• Westland Whirlwind (helicopter)
• Sikorsky H-34

Comparable aircraft

• Mil Mi-4

Related lists

• List of military aircraft of the United States
• List of helicopters
• List of civil aircraft

References

• Duke, R.A., Helicopter Operations in Algeria [Trans. French], Dept. of the Army (1959)
• France, Operations Research Group, Report of the Operations Research Mission on H-21 Helicopter Dept. of the Army (1957)
• Riley, David, French Helicopter Operations in Algeria, Marine Corps Gazette, February 1958, pp. 21–26.
• Shrader, Charles R., The First Helicopter War: Logistics and Mobility in Algeria, 1954-1962, Westport, CT: Praeger Publishers (1999)
• Spenser, Jay P., Whirlybirds: A History of the U.S. Helicopter Pioneers, Seattle, WA: University of Washington Press (1998)

External links

• H-19 US Army Aviation history fact sheet
• H-19 Chickasaw on GlobalSecuity.org
• USMC Sikorsky HRS (H-19) Database

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Sikorsky S-55".