Sikorsky H-34

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Sikorsky H-34 / S-58
Sikorsky S-58 landing c.jpg
Role Helicopter
Manufacturer Sikorsky Aircraft
First flight 8 March 1954
Introduction 1954
Status out of production, still in civilian service
Primary users United States Army
United States Navy
United States Marines
Number built 2,108
Developed from Sikorsky S-55
Variants Westland Wessex

The Sikorsky H-34 (company designation S-58) is a piston-engined military helicopter that was originally designed by American aircraft manufacturer Sikorsky for the United States Navy for service in the anti-submarine warfare (ASW) role. It has seen extended use when adapted to turbine power by the British licensee as the Westland Wessex and Sikorsky as the later S-58T.

Various H-34s served, mostly as medium transports, on every continent with the armed forces of twenty-five countries—from combat in Algeria, the Dominican Republic, Nicaragua, and throughout Southeast Asia, in roles such as saving flood victims, recovering astronauts, fighting fires, and carrying presidents. As one of the last piston-powered helicopter designs before its replacement by turbine-powered types such as the UH-1 Huey and CH-46 Sea Knight, it would see a remarkably long run of 2,108 H-34s produced between 1953 and 1970.[1]


A U.S. Navy HSS-1 with the sonar deployed, in 1960.
CH-37C and UH-34D of the United States Marine Corps.

The Sikorsky S-58 was developed as a lengthened and more powerful version of the Sikorsky (model S-55) or UH-19 Chickasaw, with a similar nose, but with a tail-dragger rear fuselage and landing gear, rather than the high-tail, 4-post pattern. It retained the nose-mounted piston engine with the drive shaft passing through the cockpit placed high above the cargo compartment.

The aircraft first flew on 8 March 1954. The first production aircraft was ready in September and entered in service for the United States Navy initially designated HSS-1 Seabat (in its anti-submarine configuration) and HUS-1 Seahorse (in its utility transport configuration) under the U.S. Navy designation system for U.S. Navy, United States Marine Corps (USMC) and United States Coast Guard (USCG) aircraft. The U.S. Army and Marine Corps, respectively, ordered it in 1955 and 1957. Under the United States Army's aircraft designation system, also used by the United States Air Force, the helicopter was designated H-34. The U.S. Army also applied the name Choctaw to the helicopter. In 1962, under the new unified DoD aircraft designation system, the Seabat was redesignated SH-34, the Seahorse as the UH-34, and the Choctaw as the CH-34.

Roles included utility transport, anti-submarine warfare, search and rescue, and VIP transport. In it standard configuration transport versions could carry 12 to 16 troops, or eight stretcher cases if utilized in the MedEvac role, while VIP transports carried significantly fewer people in significantly greater comfort.

A total of 135 H-34s were built in the U.S. and assembled by Sud-Aviation in France, 166 were produced under licence in France by Sud-Aviation for the French Air Force, Navy and Army Aviation (ALAT).

The CH-34 was also built and developed under license from 1958 in the United Kingdom by Westland Aircraft as the turbine engined Wessex which was used by the Royal Navy and Royal Air Force. The RN Wessex was fitted out with weapons and ASW equipment for use in an antisubmarine role. The RAF used the Wessex, with turboshaft engines, as an air/sea rescue helicopter and as troop transporter. Wessexes were also exported to other countries and produced for civilian use.

Operational history[edit]

Algerian War[edit]

Main article: Algerian War

The helicopters used by the French Army Light Aviation (ALAT), including the Sikorsky H-34, aggregated over 190,000 flying hours in Algeria (over 87,000 for the H-21 alone) and helped to evacuate over 20,000 French combatants from the combat area, including nearly 2,200 at night. By the time the war in Algeria had ended, eight officers and 23 non-commissioned officers from ALAT had given their lives in the course of their duties.

The use during the Algerian War of armed helicopters coupled with helicopter transport which can drop troops into enemy territory gave birth to the tactics of airmobile warfare continues today.[2]

Vietnam War[edit]

A U.S. Coast Guard HUS-1G in 1960.

French evaluations on the reported ground fire vulnerabilities of the CH-34 may have influenced the U.S. Army's decision to deploy the CH-21 Shawnee to Vietnam instead of the CH-34, pending the introduction into widespread service of the Bell UH-1 Iroquois. U.S. Army H-34s did not participate in Vietnam, and did not fly in the assault helicopter role, however a quantity were supplied to the Army of the Republic of Vietnam. These saw little use due to a lack of spare parts and maintenance.[3]

U.S. Marine Corps UH-34Ds over Mekong Delta.
U.S. Marine Corps UH-34Ds over Vietnam, 1965.

Its higher availability and reliability due to its simplicity compared to the newer helicopters led Marines to ask for it by name. The phrases "give me a HUS", "get me a HUS" and "cut me a HUS" entered the U.S. Marine Corps vernacular, being used even after the type was no longer in use to mean "help me out".[4]

USMC H-34s were also among the first gunship helicopters trialled in theatre, being fitted with the Temporary Kit-1 (TK-1), comprising two M60C machine guns and two 19-shot 2.75 inch rocket pods. The operations were met with mixed enthusiasm, and the armed H-34s, known as "Stingers" were quickly phased out. The TK-1 kit would form the basis of the TK-2 kit used on the UH-1E helicopters of the USMC.

Post-Vietnam War[edit]

The H-34 remained in service with United States Army and Marine Corps aviation units well into the late 1960s, and was standard equipment in Marine Corps Reserve, Army Reserve and Army National Guard aviation units until replaced by the UH-1 Iroquois utility helicopter. Sikorsky production ceased in 1968, with 1,821 built.[5] All H-34 helicopters were retired from service in the U.S. military by the early 1970s and were the last piston-engined helicopter in the Marine Corps. On September 3, 1973, the last flight of a USMC UH-34 occurred as Bureau Number 147191 which had been formally assigned to Headquarters Squadron, FMF Pacific was flown from Quantico, Virginia to MCAS New River to be placed on static display.[6][7]


France bought 134 Choctaws in parts from the United States and assembled by Sud-Aviation. A further 166 were manufactured later locally for the French Army Light Aviation (Army), French Naval Aviation (Navy) and Air force, these again produced by Sud-Aviation.[8] The last flight of this helicopter in the French Navy was done in 1979, in the 35F squadron.

Wessex at Ascension Island 1982.

United Kingdom[edit]

Main article: Westland Wessex

The Wessex was used as a naval helicopter and as a general purpose helicopter for the army.

South Vietnam[edit]

VNAF CH-34As at Tan Son Nhut.
USMC helicopter in Vietnam.
S-58T of New York Helicopter at 34th Street Helicopter pad in 1987

The H-34 was the primary VNAF helicopter until replaced by the Bell UH-1 Huey.[9]


Israeli Air Force Sikorsky S-58 (1967)

The S-58 flew combat missions after the end of the Six Days War, mainly against Palestinians infiltrating Israel or against their bases in Jordan. On 21 March 1968, they participated in the Battle of Karameh, bringing Israeli troops in and out as well as evacuating the wounded. This was the last operation of the S-58 as it was retired shortly later, replaced by the Bell 205 and Aérospatiale Super Frelon.[10]

Civilian use[edit]

Civil S-58T powered by a Pratt & Whitney Canada PT6T Twin-Pac turbine power plant

The H-34's lift capacity was just sufficient to lift a Mercury space capsule. In 1961, the hatch of Mercury-Redstone 4 was prematurely detached and the capsule was filled with seawater. The extra weight was too much for the H-34 and the capsule, Liberty Bell 7, was emergency released and sank in deep water.[11]

In the late 1980s and early 1990s, S-58T turbine-powered helicopters were operated by New York Helicopters in scheduled passenger airline service between JFK International Airport and East 34th Street Heliport, New York.[12]


U.S. Army version of the HSS-1 powered by a 1,525 hp R-1820-84, re-designated CH-34A in 1962, 359 built and 21 transferred from the U.S. Navy.
Designation for H-34A used for weapon tests.
Staff transport conversions of H-34A.
H-34As converted with detail changes, became CH-34B in 1962.
H-34B design with detail changes converted from H-34As, became CH-34C in 1962.
Designation for CH-34C used for weapon tests.
Staff transport conversions of CH-34C.
Designation applied to aircraft given USAF serials to be transferred under MAP and MDAP.
HUS-1L re-designated in 1962
HUS-1 re-designated in 1962 and 54 new build.
HUS-1Z re-designated in 1962
HUS-1A re-designated in 1962
HUS-1G re-designated in 1962
YHSS-1 re-designated in 1962
HSS-1 re-designated in 1962
HSS-1F re-designated in 1962
SH-34Js on the USS Essex in 1962
YHSS-1N re-designated in 1962
HSS-1N re-designated in 1962
SH-34J without ASW equipment for cargo and training purposes.
Ex-USN UH-34Js operated by the U.S. Air Force
Staff transport conversions of SH-34J.
XHSS-1 Seabat
Three Sikorsky S-58s for evaluation by the U.S. Navy, re-designated YHSS-1 then YSH-34G in 1962.
HSS-1 Seabat
Production Anti-Submarine model for the U.S. Navy, re-designated SH-34G in 1962, 215 built
HSS-1F Seabat
One HSS-1 re-engined with two YT-58-GE as a flying test bed, re-designated SH-34H in 1962.
YHSS-1N Seabat
One HSS-1 converted as the HSS-1N prototype, re-designated YSH-34J in 1962.
HSS-1N Seabat
Night/Bad weather version of the HSS-1 with improved avionics and autopilot, re-designated SH-34J in 1962, 167 built (an addition 75 HSS-1 airframes were built to CH-34C standard for West Germany).
HUS-1 Seahorse
Utility transport version of the HSS-1 for the U.S. Marine Corps, re-designated UH-34D in 1962, 462 built
HUS-1A Seahorse
Forty HUS-1s fitted with amphibious pontoons, re-designated UH-34E in 1962.
HUS-1G Seahorse
United States Coast Guard version of the HUS-1, re-designated HH-34F in 1962, six built.
HUS-1L Seahorse
Four HUS-1s converted for antarctic operations with VXE-6, re-designated LH-34D in 1962.
HUS-1Z Seahorse
Seven HUS-1s fitted with VIP interior for the Executive Flight Detachment, re-designated VH-34D in 1962.
Canadian military designation for the S-58B.
Commercial designation for basic cargo variant, certified in 1956
Commercial designation for improved cargo variant, certified in 1956
Commercial passenger transport/airliner version, certified in 1956
Commercial airliner/freighter version, certified in 1961
Certified in 1971
Certified in 1972 an increased maximum weight variant of the S-58B.
Certified in 1972 an increased maximum weight variant of the S-58C.
Certified in 1972 an increased maximum weight variant of the S-58D.
Certified in 1972 an increased maximum weight variant of the S-58E
Commercial conversion to turboshaft power using Pratt & Whitney Canada PT6T-3 Twin-Pac turboshaft with special nose cowling featuring distinctive twin rectangular air intakes, designations relate to original model:
Turboshaft powered-converstion of the S-58B
Turboshaft powered-converstion of the S-58D
Turboshaft powered-converstion of the S-58E
Turboshaft powered-converstion of the S-58F
Turboshaft powered-converstion of the S-58H
Turboshaft powered-converstion of the S-58J
Orlando Heli-Camper
RV conversion by Winnebago Industries and Orlando Helicopter, fitted with a Wright Cyclone R-1820-24 engine.
Orlando Airliner
Commercial conversion. 18-seat passenger transport helicopter.
Westland Wessex
Licence production and development in the United Kingdom.


 Costa Rica
 West Germany
 South Vietnam
 Republic of China
 United States

Accidents and incidents[edit]

  • 27 July 1960 Chicago Helicopter Airways Flight 698 a S-58C registered N879 crashed into Forest Home Cemetery, Forest Park, Illinois, United States with the loss of 11 passengers and two crew. The investigation concluded that the helicopter became uncontrollable as a result of structural disintegration in flight caused by a fatigue failure of the main rotor blade.[39]
  • 13 March 2011 Sikorsky S-58ET, N33602, suffered an engine failure, descended and veered off the side of an office building in El Segundo, California, while lifting an air conditioning external unit from the roof. The commercial pilot was seriously injured, the helicopter was substantially damaged and consumed by a post-impact fire. The helicopter was registered to Heli Flight, Inc., and operated by Aris Helicopters.[40]

Aircraft on display[edit]

Sikorsky UH-34D Seahorse in National Air and Space Museum
  • The two SH-34J Seabats received by the Chilean Navy are readied for display in 2014. The example serialled Naval 52 was exhibited by the first time during Exponaval 2014, in December 2014.[41]

The first example, Naval 51 is undergoing restoration at Museo Nacional Aeronáutico y del Espacio de Chile, at the former Los Cerrillos airport after many years displayed in wrong colour scheme.[42]

  • HSS-1, No. 182, is on display at the Base d'aéronautique navale d'Hyères, the military part of the Toulon–Hyères Airport in France.[43] Serving until 1977 with 31F squadron, it was one of the last operational H-34's in French Naval Aviation. Now restored, No. 182 is displayed in the typical navy blue color of the French navy's helicopters of this time period.[44]
  • S-58T, H4K-64/30 / 20117 (cn 58-1117) at the Royal Thai Air Force Museum, Bangkok, Thailand.[45]
  • UH-34D Seahorse (S-58A) 150556 (cn 58-1683) at Royal Thai Air Force Museum, Bangkok, Thailand.[45]
United States

Specifications (H-34 Choctaw)[edit]

Sikorsky SH-34 orthographical image.svg

General characteristics



See also[edit]

Related development
Aircraft of comparable role, configuration and era
Related lists



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  3. ^ Mesko 1984, pp. 4–6.
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  5. ^ Endres, Günter G. Jane's Helicopter Markets and Systems. Coulsdon, Surrey, UK: Jane's Information Group, 1996. ISBN 978-0-7106-1363-9.
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  8. ^ "Sikorsky H-34 / CH-34 Choctaw." Retrieved: 17 January 2011.
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  30. ^ "Sikorsky H-34 / CH-34 Choctaw - Transport / Close-Support Helicopter - History, Specs and Pictures - Military Aircraft". Retrieved 2014-01-20. 
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  39. ^ "CAA 429 World Airline Accident Summary with reference to Civil Aeronautics Board Aircraft Accident Report SA-357." United Kingdom CAA Document.
  40. ^ "NTSB Identification: WPR11FA163." Retrieved: 26 July 2011.
  41. ^ "Presentaron al Sikorsky SH-34J Seabat Naval 52". 
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  43. ^ Avions-lé, ed. (July 29, 2012). "Le Sikorsky de Palyvestre" (in French). Retrieved 22 August 2014. 
  44. ^ "Les hélicoptères anciens en France - Les Sikorsky H-34 et HSS-1" (in French). Retrieved 22 August 2014. 
  45. ^ a b Royal Thai Air Force Museum: "Building 5: Helicopters and last propeller fighter.", Retrieved: 17 January 2011.
  46. ^ "UH-34D Seahorse, Sikorsky." Patriot's Point Naval and Maritime Museum. Retrieved: 26 July 2011.
  47. ^ Squadron restores pre-Vietnam helicopters, Retrieved 9 December 2014
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  58. ^ Apostolo 1984, p. 84.


  • Apostolo, Giorgio. The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books, 1984. ISBN 0-517-439352.
  • Duke, R.A. Helicopter Operations in Algeria [Translated French]. Washington, DC: Dept. of the Army, 1959.
  • Fails, William R. Marines & Helicopters, 1962-1973. Darby, Pennsylvania: Diane Publishing, 1995. ISBN 0-7881-1818-8.
  • Griffin, John A. Canadian Military Aircraft Serials & Photographs 1920 - 1968. Ottawa: Queen's Printer, Publication No. 69-2, 1969.
  • Gunston, Bill. An Illustrated Guide To the Israeli Air Force. London: Salamander Books, 1982. ISBN 978-0-668-05506-2.
  • Leuliette, Pierre. St. Michael and the Dragon: Memoirs of a Paratrooper, New York: Houghton Mifflin, 1964.
  • Mesko, Jim: Airmobile: The Helicopter War in Vietnam. Carollton, Texas: Squadron/Signal Publications, 1984. ISBN 0-89747-159-8.
  • 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, Connecticut: Praeger Publishers, 1999. ISBN 0-275-96388-8.
  • Apostolo, Giorgio. The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books, 1984. (page 84) ISBN 0-517-439352.
  • Spenser, Jay P. Whirlybirds: A History of the U.S. Helicopter Pioneers. Seattle, Washington: University of Washington Press, 1998. ISBN 0-295-97699-3.

Further reading[edit]

  • Núñez Padin, Jorge Felix; Cicalesi, Juan Carlos (2011). Núñez Padin, Jorge Felix, ed. Sikorsky S-55/H-19 & S-58/T. Serie en Argentina (in Spanish) 6. Bahía Blanca, Argentina: Fuerzas Aeronavales. ISBN 978-987-1682-13-3. Retrieved 2014-08-24. 

External links[edit]

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