The Sikorsky H-34 Choctaw (also known as the S-58) was a military helicopter originally designed by American aircraft manufacturer Sikorsky for the United States Navy for service in the anti-submarine warfare (ASW) role.

Sikorsky H-34s have served on every continent with the armed forces of twenty-five countries - from combat in Algeria, the Dominican Republic, Nicaragua, and throughout southeast Asia, to saving flood victims, recovering astronauts, fighting fires, and carrying presidents.

Development

The Sikorsky S-58 was developed from the Sikorsky's UH-19 Chickasaw. The aircraft first flew on 8 March 1954. It was initially designated HSS-1 Seabat (in its anti-submarine configuration) and HUS-1 Seahorse (in its utility transport configuration) under the US Navy designation system for US Navy, US Marine Corps and US Coast Guard aircraft. Under the US Army's aircraft designation system, also used by the US Air Force, the helicopter was designated H-34. The US 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

The U.S. Coast Guard flew the H-34 helicopter from 1959 to 1962.

In 1955, the U. S. Marine Corps received its first HUS-1s as an interim type until the HR2S (later H-37) entered squadron service. However, the HUS lasted far longer in USMC service, and in much greater numbers, than the HR2S ever did. Ultimately the Marine Corps took delivery of 515 UH-34Ds. From the late 1950s until the CH-46 entered service in 1965, the UH-34 operated as the mainstay of Marine Corps helicopter units.

Vietnam

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. US 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 lack of spare parts and maintenance.

The U.S. Marine Corps (USMC) continued to use the H-34 pattern even after the U.S. Army had phased it out. Even after the USMC adopted their own version of the UH-1, the UH-1E, the CH-34s continued to be used up to and for a period after the Tet Offensive in 1968.

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 USMC vernacular, being used even after the type was no longer in use to mean "help me out".

U.S. Marine Corps H-34s were also among the first gunship helicopters trialled in theatre, being fitted with the Temporary Kit-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.

In August 1969, the last Marine UH-34D in Vietnam was retired from HMM-362 at Hue Phu Bai. During that period, enemy action and accidents downed 134 helicopters. Most of the twenty surviving CH-34 helicopters were turned over to the South Vietnamese during the course of the war, though a few were ultimately reclaimed by the Army prior to the final collapse of the Saigon Government.

Pilots of H-34s in Vietnam discovered that some of the design's innovative features carried penalties. The high cockpit made it an obvious target, and the drive shaft created a partition that made it difficult for crew chiefs to come to the aid of the cockpit crew if they became injured. The H-34's magnesium skin resulted in very intense fires, and contributed to significant corrosion problems. The airframe was also too weak to support most of the weapon systems that allowed the UH-1s to become an effective ad-hoc gunship. Nonetheless, the H-34 demonstrated an ability to sustain a substantial amount of combat damage and still return home.

In the late 1950s, Air America, a CIA-created airline, began flying UH-34Ds in Laos, manned by crews on leave from the Marine Corps. When the last military UH-34 left Vietnam, Air America was still in operation with the type, including upgraded S-58Ts.

Post-Vietnam War

The CH-34 Choctaw remained in service with US Army aviation units well into the late 1960s, and was standard equipment in Army Reserve and Army National Guard aviation units, until replaced by the UH-1 Iroquois utility helicopter. Indeed, the last Choctaw was not officially retired until the early 1970s. Sikorsky production ceased in 1970, with 1,800 built.

Foreign Service

France

The French Navy adopted the SH-34 Seabat in 1955, using the helicopter during the Algerian War of 1956-62. Beginning in 1956, the H-34 saw its introduction into combat during intensive operations with the French in Algeria. The French Army had earlier modified the H-19 and Piasecki H-21 with rockets and machine guns for use in a ground attack role; the French Navy performed the same modification to the CH-34 which was developed under the name Pirate and was extensively used in counter-insurgency airborne operations. The H-19 proved underpowered for the ground attack role, and the H-21 lacked mobility. The H-34 was able to carry more armament, including a MG151 20 mm cannon firing from the cabin door, two M2 .50 cal. machine guns firing from the cabin windows to port, and batteries of 37- or 68-mm rockets. 73 mm rockets and additional machine guns were also employed on some versions. Official evaluations at the time had indicated that the CH-21 was more likely to survive multiple hits by ground fire than was the CH-34; this was assumed to be a consequence of the location and construction of the CH-34's fuel tanks.

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, Navy and Air force, these again produced by Sud-Aviation.

United Kingdom

The helicopter was also built and developed under license from 1958 in the United Kingdom by Westland Aircraft under the name "Wessex". The Royal Navy was the primary user for the Anti-Submarine Warfare role. The RAF and Royal Marines used the Wessex, with Rolls-Royce Gnome turboshaft engines, as an air/sea rescue helicopter and as troop transporter.

South Vietnam

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

Israel

A joint air force/paratroops delegation studied helicopters used by the French Army Aviation and recommended the acquisition of the Sikorsky S-58 and on February 13, 1958, the first pair arrived in Israel, followed by another helicopter in March. The "Rolling Sword" squadron, which operated all IAF helicopters at the time, operated only a few examples until 1962 when 24 S-58s earmarked for the West German air force were covertly routed to Israel.

At the outbreak of the Six Days War the "Rolling Sword" squadron had 28 airworthy S-58s. The helicopters begun the war evacuating downed pilots, but became more involved as the ground war progressed. On the night of June 5-6, the S-58s airlifted 600 soldiers behind Egyptian lines in the center of the Sinai Peninsula after Israeli armor had met fierce resistance. This ground force destroyed an Egyptian artillery position, hastening the collapse of the Egyptian front. On June 7, S-58s were tasked with airlifting Israeli paratroops to capture the southernmost point in the Sinai, Sharm el-Sheikh, but arrived at the site to find it abandoned.

During the final operation of the war, the conquest of the Golan Heights from the Syrians, the S-58s flew Israeli paratroops in to take control of the southern Golan. In three separate airlifts on June 9-10, the paratroops were inserted behind Syrian lines and attacked retreating Syrian forces.

The S-58 continued to fly combat missions after the end of the war, mainly against Palestinians infiltrating Israel or against their bases in Jordan. On March 21, 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.

Civilian use

• The H-34's lift capacity was just sufficient enough to lift a Mercury capsule. In 1961, the hatch of Mercury 4 was prematurely detached and the capsule was filled with seawater. That extra weight was too much for the H-34 and Liberty Bell 7 was emergency released (in the deep sea).
• In the 1990s, an S-58ET called Miss Piggy from "New York Helicopter" flew passengers from JFK International Airport to East 34th Street Heliport, New York.
• H-34 have been used by forest firefighting contractors in Ontario.
• At least one S-58 was purchased for civilian use by Oregon-based Columbia Helicopters in the 1960s.
• In 1968, an S-58 was used to remove the wreckage of a Bell 47 G2 helicopter from the top of Uluru.
• The 1980s television series Riptide, featured a military-surplus H-34 called "The Screaming Mimi".

Variants

H-34A

US 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 US Navy.

JH-34A

Designation for H-34A used for weapon tests.

VH-34A

Staff transport conversions of H-34A.

H-34B

H-34As converted with detail changes, became CH-34B in 1962.

H-34C

H-34B design with detail changes converted from H-34As, became CH-34C in 1962.

JH-34C

Designation for CH-34C used for weapon tests.

VH-34C

Staff transport conversions of CH-34C.

HH-34D

Designation applied to aircraft given USAF serials to be transferred under MAP and MDAP.

LH-34D

HUS-1L re-designated in 1962

UH-34D

HUS-1 re-designated in 1962 and 54 new build.

VH-34D

HUS-1Z re-designated in 1962

UH-34E

HUS-1A re-designated in 1962

HH-34F

HUS-1G re-designated in 1962

YSH-34G

YHSS-1 re-designated in 1962

SH-34G

HSS-1 re-designated in 1962

SH-34H

HSS-1F re-designated in 1962

YSH-34J

YHSS-1N re-designated in 1962

SH-34J

HSS-1N re-designated in 1962

UH-34J

SH-34J without ASW equipment for cargo and training purposes.

HH-34J

Ex-USN UH-34Js operated by the US Air Force

VH-34J

Staff transport conversions of SH-34J.

XHSS-1 Seabat

Three Sikorsky S-58s for evaluation by the US Navy, re-designated YHSS-1 then YSH-34G in 1962.

HSS-1 Seabat

Production Anti-Submarine model for the US 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 US 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.

S-58

Commercial designation for basic cargo variant

S-58B

Commercial designation for improved cargo variant

S-58C

Commercial passenger transport/airliner version

S-58D

Commercial airliner/freighter version

S-58T

Commercial conversions to turboshaft power by Sikorsky, Orlando Helicopter, and California Helicopter.

S-58 Heli-Camper

Commercial conversion, fitted with a Wright Cyclone R-1820-24 engine.

Orlando Airliner

Commercial conversion. 18-seat passenger transport helicopter.

Operators

• : U.S. Air Force, U.S Army, U.S. Marine Corps, U.S. Navy, U.S. Coast Guard

Accidents and incidents

• 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.

Specifications (H-34 Choctaw)

Aircraft on Display

There is an UH-34D Seahorse on display on the flight deck of the at the Patriot's Point Naval and Maritime Museum in Charleston, SC.

See also

References

Notes

1. Mesko, 1984, pages 4-6
2. Fails 1995, p. 9.
3. Mercury MR-4
4. S-58ET from New York Helicopter
5. Columbia Helicopters Website
6. "Riptide - Helicopter TV show." rotaryaction.com, Pigaus Press, 2005. Retrieved: 5 March 2009.
7. United Kingdom CAA Document CAA 429 World Airline Accident Summary with reference to Civil Aeronautics Board Aircraft Accident Report SA-357

Bibliography

• Duke, R.A., Helicopter Operations in Algeria [Trans. French], Dept. of the Army, 1959.
• Fails, William R. Marines & Helicopters, 1962-1973. Darby, PA: Diane Publishing, 1995. ISBN 0-78811-818-8.
• Leuliette, Pierre. St. Michael and the Dragon: Memoirs of a Paratrooper, New York: Houghton Mifflin, 1964.
• Mesko, Jim: Airmobile - The Helicopter War in Vietnam. 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, CT: Praeger Publishers, 1999. ISBN 0-275-96388- 8.
• Spenser, Jay P. Whirlybirds: A History of the U.S. Helicopter Pioneers. Seattle, WA: University of Washington Press, 1998. ISBN 0-29597-699-3.

External links

• CH-34 US Army Aviation history fact sheet
• Sikorsky H-34 Choctaw on shanaberger.com