Sikorsky H-34 Explained

The Sikorsky H-34 (company designation S-58) is an American piston-engined military utility helicopter originally designed by Sikorsky as an anti-submarine warfare (ASW) aircraft for the United States Navy. A development of the smaller Sikorsky H-19 Chickasaw (S-55), the H-34 was originally powered by a radial engine, but was later adapted to turbine power by the British licensee as the Westland Wessex and by Sikorsky as the S-58T. The H-34 was also produced under license in France by Sud Aviation.

The H-34 was one of the first successful military utility helicopters, serving on every continent with the armed forces of 25 countries. It saw combat in the Dominican Republic, Nicaragua, the Six-Day War, the Vietnam War, and the Algerian War, where the French Air Force used it to pioneer modern air assault tactics. It was the last piston-engined helicopter to be operated by the United States Marine Corps (USMC), having been replaced by turbine-powered types such as the UH-1 Huey and CH-46 Sea Knight; in the USMC, the H-34 was often called the "HUS" after its original designation in that service. A total of 2,340 H-34s were manufactured between 1953 and 1970, including the license productions in the UK and France.[1]

Although most military forces retired the H-34 by the late 20th century, the type remains in limited civil use in transport and external cargo lift roles, and some have been restored and flown as warbirds.

Development

In the early 1950s Sikorsky developed the S-58, an improved version of the S-55, which had enter service as the H-19 with the United States. The United States Navy issued a contract in 1952 for the S-58, entering service as the HUS-1, the Army placing a contract in 1955 as the H-34, and the Marine Corp in 1957 (as the HUS-1).[2] In 1962 these names were standardized to H-34, with additional prefixes and letters according to that U.S. designation system.[3] Westland had already made a version of the predecessor of the S-58, the S-55 as the Westland Wirlwind, and they would go on to make a turbine powered version of the S-56 as the Westland Wessex.

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 radial reciprocating 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 its 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 much greater comfort.

A total of 135 H-34s were built in the US 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 turboshaft 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

Entering service in the 1950s, the type served numerous roles in the late 20th century.

The type was internationally and commercially.

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 been killed.

The use of armed helicopters during the Algerian War, coupled with helicopter transports which can insert troops into enemy territory, gave birth to some of the modern tactics of airmobile warfare.[4]

Vietnam War

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, but a quantity were supplied to the Republic of Vietnam Air Force (RVNAF). These saw little use due to a lack of spare parts and maintenance.[5] 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".[6]

USMC H-34s were also among the first helicopter gunships 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.

An H-34 was featured in the famous early-Vietnam War Time-Life photo essay "One Ride With Yankee Papa 13", photographer Larry Burrows, which depicted stages of a disastrous combat mission in which several crew were wounded or killed.[7]

Post-Vietnam War

The H-34 remained in service with United States Army and Marine Corps aviation units into the late 1960s; at this time it was also standard equipment in Marine Corps Reserve, Army Reserve and Army National Guard aviation units, eventually being replaced by the UH-1 Iroquois utility helicopter. Sikorsky terminated all production activities in 1968, a total of 1,821 having been built.[8] All H-34 helicopters were retired from service in the U.S. military by the early 1970s; the type having the distinction of being the last piston-engined helicopter to be operated by the Marine Corps. On 3 September 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.[9] [10]

France

France purchased an initial batch of 134 Choctaws; these were shipped in kit-form from the United States and locally assembled by Sud-Aviation. Later, a further 166 were domestically manufactured by Sud-Aviation; these were operated by the French Army Light Aviation (Army), French Naval Aviation (Navy) and Air force.

United Kingdom

See main article: Westland Wessex. The Wessex was used as an anti-submarine and utility helicopter with the Royal Navy and as a transport and search and rescue helicopter with the Royal Air Force. British Wessex saw action in several conflicts: Falklands, Oman, Borneo, Aden, etc.

The twin-turbine Wessex served into the 21st century, and was one of the longest serving and successful of the H-34 types.

South Vietnam

Used by RVNAF 219th Squadron to insert MACV-SOG reconnaissance teams into Laos.[11] The H-34 was the primary RVNAF helicopter until replaced by the Bell UH-1 Huey.[12]

South Vietnam was taken over by North Vietnam, and the fate of these aircraft

Israel

Israeli S-58s flew numerous combat missions after the end of the Six-Day War; these missions were mainly against Palestinians infiltrating Israel or against their bases in Jordan. On 21 March 1968, various S-58s participated in the Battle of Karameh, bringing Israeli troops in and out of the theatre as well as evacuating the wounded. This was the last operation of the S-58 as it was retired shortly later, having been replaced by the newer Bell 205 and Aérospatiale Super Frelon.[13]

Civilian use

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,[14] remaining on the ocean floor until 1999.

Sikorsky set up a production line in 1970 to remanufacture existing S-58 aircraft into the S-58T configuration, replacing the R-1820 engine with a pair of Pratt & Whitney Canada PT6T-3 Twin-Pac turboshafts; Sikorsky obtained a Federal Aviation Administration type certificate for the conversion in April 1971. The conversion enhanced safety, allowing the aircraft to continue flight after an engine failure, and greatly improved its hot and high performance; whereas the R-1820 could only provide full power up to an altitude of, the paired PT-6s provide full power up to, and an S-58T can fly at maximum gross weight up to . The type certificate for the S-58T was sold to California Helicopter International in 1981.[15]

In the late 1980s and early 1990s, S-58T helicopters were operated by New York Helicopters in scheduled passenger airline service between JFK International Airport and East 34th Street Heliport, New York.[16] In the early 1970s, Orlando Helicopter Airways developed a novel civil conversion of the S-55/H-19, the Heli-Camper, a campervan-like conversion—featuring a built-in mini-kitchen and sleeping accommodations for four.[17] Later in that decade, Orlando developed a larger version based on the S-58 and participated in a joint effort with popular American recreational vehicle (RV) manufacturer Winnebago Industries to market both aircraft as the Winnebago Heli-Home. The S-58 version featured a larger kitchenette, sleeping accommodations for six, a minibar, and an entertainment system; optional floats were offered for amphibious operations. The aircraft were featured in several American popular magazines and reportedly drew large crowds at RV shows and dealerships, but their high purchase price together with rising 1970s fuel prices resulted in very limited sales; production is not well documented but is estimated at only six or seven of the S-55 and S-58 versions combined.[18]

Variants

H-34A
  • 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.
    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 U.S. Air Force
    VH-34J
  • 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.
    CH-126
  • Canadian military designation for the S-58B.
    S-58A
  • Commercial designation for basic cargo variant, certified in 1956
    S-58B
  • Commercial designation for improved cargo variant, certified in 1956
    S-58C
  • Commercial passenger transport/airliner version, certified in 1956
    S-58D
  • Commercial airliner/freighter version, certified in 1961
    S-58E
  • Certified in 1971
    S-58F
  • Certified in 1972 an increased maximum weight variant of the S-58B.
    S-58G
  • Certified in 1972 an increased maximum weight variant of the S-58C.
    S-58H
  • Certified in 1972 an increased maximum weight variant of the S-58D.
    S-58J
  • Certified in 1972 an increased maximum weight variant of the S-58E
    S-58T
  • 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:
    S-58BT
  • Turboshaft-powered conversion of the S-58B
    S-58DT
  • Turboshaft-powered conversion of the S-58D
    S-58ET
  • Turboshaft-powered conversion of the S-58E
    S-58FT
  • Turboshaft-powered conversion of the S-58F
    S-58HT
  • Turboshaft-powered conversion of the S-58H
    S-58JT
  • Turboshaft-powered conversion of the S-58J
    Orlando Heli-Camper / Winnebago Heli-Home
  • RV conversion by Winnebago Industries and Orlando Helicopter, fitted with a Wright Cyclone R-1820-24 engine[18]
    Orlando Airliner
  • Commercial conversion. 18-seat passenger transport helicopter.
    Westland Wessex Licence production and development in the United Kingdom.

    Operators

    Kingdom of Laos

    Accidents and incidents

    Aircraft on display

    Canada

    Chile

    France

    Germany

    Indonesia

    Netherlands

    Thailand

    Philippines

    United States

    Bibliography

    Further reading

    External links

    Notes and References

    1. http://www.uswarplanes.net/h34.html "H-34."
    2. Web site: Sikorsky S-58 – Igor I Sikorsky Historical Archives . 2024-08-07 . en-US.
    3. Web site: Sikorsky S-55, S-56, & S-58 . 2024-08-07 . www.airvectors.net.
    4. http://histoire-militaire.pagesperso-orange.fr/aviation/helicoalgerie.htm helicopters during the war in Algeria
    5. Mesko 1984, pp. 4–6.
    6. Fails 1995, p. 9.
    7. Burrows . Larry . 16 April 1965 . One Ride With Yankee Papa 13 . Life . 24-34C . 28 January 2023.
    8. Endres, Günter G. Jane's Helicopter Markets and Systems. Coulsdon, Surrey, UK: Jane's Information Group, 1996. .
    9. Fails 1995, p. 127.
    10. http://www.marines.mil/Portals/59/Publications/Marines%20and%20Helicopters%201962-1973%20%20PCN%2019000307400_2.pdf MARINES AND HELICOPTERS, 1962–1973
    11. Across The Fence, John Stryker Meyer
    12. https://web.archive.org/web/20150925061100/http://www.dtic.mil/srch/doc?collection=t3&id=ADA439993 The Vietnamese Air Force, 1951–1975. An Analysis of Its Role in Combat and Fourteen Hours at Koh Tang. Volume 3, USAF Southeast Asia monograph series 4 and 5.
    13. Gunston 1982, p. 92.
    14. Wade, Mark. "Mercury MR-4." astronautix.com, 29 April 2009. Retrieved (from archive): 26 July 2011.
    15. Web site: Sikorsky Archives / S-58 . Devine . Vinny . June 2011 . Sikorsky Product History . Igor Sikorsky Historical Archives . 29 July 2022.
    16. Brown, Allan. "S-58ET from New York Helicopter." airliners.net. Retrieved: 17 January 2011.
    17. Web site: S-55/H-19/HO4S/HRS Helicopter . Devine . Vinny . November 2012 . Sikorsky Product History . Igor Sikorsky Historical Archives . 7 July 2015.
    18. Web site: The Flying Winnebago . Chiles . James R. . Air & Space Magazine . January 2012 . July 28, 2022.
    19. http://www.helis.com/database/modelorg/1164/ "H-58."
    20. .
    21. Griffin, 1969, p.17
    22. http://www.helis.com/database/cn/13396/ "SH-34J."
    23. http://www.airliners.net/photo/Chile---Navy/Sikorsky-HSS-1N-(S-58A)/1854999/L/&sid=03bb603eb478b4a0392904e724aa0948 "Sikorsky-HSS-1N-(S-58A)."
    24. http://www.flightglobal.com/pdfarchive/view/1981/1981%20-%202504.html "World's Air Forces 1981, p. 332.
    25. http://www.flightglobal.com/pdfarchive/view/1971/1971%20-%201043.html "World Air Forces 1971, p. 928."
    26. http://www.flightglobal.com/pdfarchive/view/1981/1981%20-%202518.html "World's Air Forces 1981, p. 346."
    27. http://www.flightglobal.com/pdfarchive/view/2004/2004-09%20-%202358.html "World's Air Forces 2004, p. 65."
    28. http://www.flightglobal.com/pdfarchive/view/1968/1968%20-%201208.html "World Air Forces 1968, p. 52 (m)."
    29. http://www.flightglobal.com/pdfarchive/view/1971/1971%20-%201049.html "=World Air Forces 1971, p. 932."
    30. http://www.flightglobal.com/pdfarchive/view/1968/1968%20-%201209.html "World Air Forces 1968, p. 53."
    31. http://www.flightglobal.com/pdfarchive/view/1981/1981%20-%202534.html "World's Air forces 1981, p. 362."
    32. http://www.flightglobal.com/pdfarchive/view/1968/1968%20-%201216.html "World Air Forces 1968, p. 60."
    33. http://www.flightglobal.com/pdfarchive/view/1981/1981%20-%202549.html "World's Air Forces 1981, p. 377."
    34. http://www.utdallas.edu/library/specialcollections/hac/cataam/Leeker/aircraft/uh341.pdf "Air America: Sikorsky UH-34s (1st series)."
    35. http://www.helis.com/database/modelorg/1053/ "US Air Force H-34."
    36. http://www.sikorskyarchives.com/S-58%20%20HELICOPTER.php "S58 (CH-34, UH-34, VH-34, SH-34, HH-34, S-58A, C, D, S-58T)."
    37. http://www.helis.com/database/org/us_united_states_coast_guard/History/2 "USCG HH-34.'
    38. http://www.flightglobal.com/pdfarchive/view/1987/1987%20-%202554.html "World's Air Forces 1987, p. 104."
    39. "CAA 429 World Airline Accident Summary with reference to Civil Aeronautics Board Aircraft Accident Report SA-357." United Kingdom CAA Document.
    40. https://www.youtube.com/watch?v=mJ61AqZIrdA"Hélices"
    41. http://articles.chicagotribune.com/2002-07-12/news/0207120256_1_helicopter-crash-sikorsky-s58t-pilot Chicago Tribune: Helicopter crash kills Woodridge man
    42. https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78540/pdf National Transportation Safety Board Aviation Accident Final Report
    43. Web site: Aviation . Reynolds Museum . Government of Alberta . 1 December 2019.
    44. Web site: Romero. Álvaro. Presentaron al Sikorsky SH-34J Seabat Naval 52. ModoCharlie. 29 October 2016. es. 8 December 2014.
    45. Web site: Romero. Álvaro. Ilustre desconocido v3.0. ModoCharlie. 29 October 2016. es. August 2008.
    46. http://www.avionslegendaires.net/2012/07/actu/le-sikorsky-de-palyvestre/ "Le Sikorsky de Palyvestre."
    47. http://celag.free.fr/helicos/reliques/H-34.htm "Les Sikorsky H-34 et HSS-1."
    48. Web site: Sikorsky S-58 (H-34 G). Deutsches Museum. 29 October 2016. 29 October 2016. https://web.archive.org/web/20161029225311/http://www.deutsches-museum.de/en/flugwerft/collections/helicopters/s-58/. dead.
    49. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 80+73 Marineflieger, c/n 58-1557. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    50. Web site: Sikorsky S-58 (H-34 GIII). Das Hubschraubermuseum Buckeburg. 29 October 2016. 24 May 2020. https://web.archive.org/web/20200524034928/http://www.hubschraubermuseum.de/exponate/einrotorige-hubschrauber/sikorsky-s-58-h-34-giii/?lang=en. dead.
    51. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 81+09 Heeresfliegertruppe, c/n 58-1679. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    52. Web site: Airframe Dossier – Sikorsky S-58C, s/n B-11 FABe, c/n 58-0356, c/r D-HAUF. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    53. Web site: H-5802 Sikorsky UH-34D Seahorse Indonesia – Air Force Thimo van Dijk . 2022-03-02 . JetPhotos . en.
    54. Web site: 2015-05-21 . Sikorsky S-58T Twin Pack: Kiprah Helikopter "Codot" TNI AU . 2022-03-02 . Indomiliter.com . en-US.
    55. Web site: H-3404 Sikorsky S-58T Indonesia – Air Force Arjun Sarup . 2022-03-02 . JetPhotos . en.
    56. Web site: 2017-11-23 . Ada Helikopter "Codot" di Museum Dirgantara Mandala Yogyakarta . 2022-03-02 . Indomiliter.com . en-US.
    57. Web site: 2018-03-06 . Gantikan PZL MS-1, Si 'Codot' Jadi Ikon Baru Monumen Lanud Atang Sendjaja . 2022-03-02 . Airspace Review . en-US.
    58. Web site: 2018-10-24 . [Photos] The Sikorsky H-34 Choctaw Monument ]. 2022-03-02 . Lovely Bogor . en-US.
    59. https://www.nmm.nl/zoeken-in-de-collectie/detail/471244/ "SH-34J / 134"
    60. Web site: Building 5:Helicopters and last propeller fighter. Royal Thai Air Force Museum. 29 October 2016. https://web.archive.org/web/20131026164825/http://www.rtaf.mi.th/MUSEUM/BLDG5-2.HTM. 26 October 2013.
    61. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n H4k-64/30 RTAF, c/n 58-1117, c/r N1170U. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    62. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, c/n 58-1683. Aerial Visuals. AerialVisuals.ca.
    63. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 153131 USN, c/n 58-1769. Aerial Visuals. AerialVisuals.ca. 8 November 2016.
    64. Web site: Helicopters. Evergreen Museum Campus. Evergreen Museum. 29 October 2016. 31 May 2017. https://web.archive.org/web/20170531024716/http://www.evergreenmuseum.org/helicopters. dead.
    65. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 138460 USN. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    66. Web site: Sikorsky UH-34D Choctaw. Estrella Warbirds Museum. 21 May 2018.
    67. Web site: Airframe Dossier – Sikorsky UH-34J Seabat, s/n 143937 USN, c/n 58-0707, c/r N85128. Aerial Visuals. AerialVisuals.ca. 21 May 2018.
    68. Web site: H-34 Seabat. USS Midway Museum. USS Midway. 29 October 2016. dead. https://web.archive.org/web/20161029114245/http://www.midway.org/node/77. 29 October 2016.
    69. Web site: Airframe Dossier – Sikorsky H-34A Choctaw, s/n 143939 USN, c/n 58-0709. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    70. Web site: SIKORSKY UH-34D "SEA BAT". Harold F. Pitcairn Wings of Freedom Aviation Museum. Wings of Freedom Aviation Museum. 28 October 2016.
    71. Web site: Airframe Dossier – Sikorsky SH-34J Seabat, s/n 145694 USN, c/r N46920. Aerial Visuals. AerialVisuals.ca. 28 October 2016.
    72. Web site: Sikorsky LH-34D (S-58) 'Seabat'. New England Air Museum. 29 October 2016. https://web.archive.org/web/20160829230150/http://neam.org/index.php?option=com_content&view=article&id=878. 29 August 2016.
    73. Web site: UH-34D SEAHORSE. Patriots Point. 28 October 2016.
    74. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 147171 USN, c/n 58-1087. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    75. Web site: Sikorsky UH-34D Choctaw. Connectticut Air & Space Center. 12 January 2024.
    76. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 147173 USMC, c/r N2252X. Aerial Visuals. AerialVisuals.ca. 12 January 2024.
    77. News: Burns. Sarah. Squadron restores pre-Vietnam helicopters. 28 October 2016. JDNews.com. GateHouse Media, LLC. 1 August 2013. Jacksonville, North Carolina.
    78. Web site: c/n 58-1142. helis.com. 28 October 2016.
    79. http://www.pwam.org/aircraftdisplay1.html "SH-34J Sea Horse."
    80. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 148002 USN. Aerial Visuals. AerialVisuals.ca. 28 October 2016.
    81. Web site: Airframe Dossier – Sikorsky S-58 / H-34 / HSS / Wessex, s/n 148764 USMC, c/n 58-1315. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    82. Web site: Sikorsky UH-34D Seahorse. Smithsonian National Air and Space Museum. 29 October 2016. https://web.archive.org/web/20150510062112/http://airandspace.si.edu/collections/artifact.cfm?id=A19750823000. 10 May 2015.
    83. Web site: Panko. Ray. Sikorsky H-34 Choctaw/Seabat/Seahorse. Pacific Aviation Museum Pearl Harbor. 28 October 2016. 26 August 2013. 27 October 2016. https://web.archive.org/web/20161027182828/http://www.pacificaviationmuseum.org/pearl-harbor-blog/sikorsky-h-34-choctaw-seabat-seahorse. dead.
    84. Web site: Aircraft. 4 January 2024.
    85. Web site: Aircraft Listing. Flying Leathernecks. Flying Leatherneck Historical Foundation. 29 October 2016. 4 March 2016. https://web.archive.org/web/20160304030559/http://flyingleathernecks.org/wp-content/uploads/2013/10/Aircraft_Listing.pdf. dead.
    86. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 150219 USN, c/n 58-1559. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    87. Web site: H-34 SEABAT/SEAHORSE. National Naval Aviation Museum. Naval Aviation Museum Foundation. 28 October 2016.
    88. O'Connell, Jim. "Pete VX-6." Radiocom.net. Retrieved: 4 September 2012.
    89. Web site: SIKORSKY UH-34D. Wings & Rotors Air Museum. 5 December 2016. dead. https://web.archive.org/web/20161113133424/http://wingsandrotors.org/sikorsky/. 13 November 2016.
    90. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 150255 USMC. Aerial Visuals. AerialVisuals.ca. 5 December 2016.
    91. Web site: Sikorsky UH-34D. Platinum Fighter Sales. 5 December 2016. dead. https://web.archive.org/web/20161215125410/http://www.platinumfighters.com/uh-34. 15 December 2016.
    92. Web site: UH-34D Seahorse. USS Hornet Sea, Air & Space Museum. USS Hornet. 28 October 2016. dead. https://web.archive.org/web/20161029113550/http://www.uss-hornet.org/visit-hornet/aircraft/uh-34d-seahorse/. 29 October 2016.
    93. Web site: Kristy. Ben. Sikorsky UH-34D. National Museum of the Marine Corps. 29 October 2016.
    94. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 150570 USN, c/n 58-1699, c/r N19YN. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    95. Web site: Aircraft. Palm Springs Air Museum. 29 October 2016.
    96. Web site: Airframe Dossier – Sikorsky UH-34D Seahorse, s/n 154895 USMC, c/n 58-1805. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    97. Web site: Aircraft Inventory. Flight Test Historical Foundation. 29 October 2016. dead. https://web.archive.org/web/20161019025925/http://afftcmuseum.org/exhibits/museum-aircraft-exhibits/. 19 October 2016.
    98. Web site: Airframe Dossier – Sikorsky S-58 / H-34 / HSS / Wessex, s/n 57-1726 USAF. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    99. Web site: Airframe Dossier – Sikorsky CH-34A, s/n 53-4526 US, c/n 58-0088. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    100. Web site: CH-34 "Choctaw". The California Military Museum. 29 October 2016.
    101. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 53-4544 USAF, c/n 58-0106. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    102. Web site: RUSSELL MILITARY MUSEUM EXHIBITS. Russell Military Museum. 29 October 2016.
    103. Web site: Airframe Dossier – Sikorsky CH-34C Choctaw, s/n 54-0914 US, c/n 58-0194. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    104. Web site: Helicopters. Carolinas Aviation Museum. 28 October 2016. https://web.archive.org/web/20110725141341/http://www.carolinasaviation.org/helicopters.htm. 25 July 2011.
    105. Web site: Airframe Dossier – Sikorsky CH-34A, s/n 55-4496 US, c/n 58-0509. Aerial Visuals. AerialVisuals.ca. 28 October 2016.
    106. News: c/n 58-509. helis.com. 28 October 2016.
    107. Web site: Rotary Wing. United States Army Aviation Museum. Army Aviation Museum Foundation, Inc.. 29 October 2016. dead. https://web.archive.org/web/20161105031344/http://www.armyaviationmuseum.org/index.php/museum/aircraft-collection/16-aircraft-collection/65-rotary-wing. 5 November 2016.
    108. Web site: Airframe Dossier – Sikorsky VH-34C, s/n 56-4320 US, c/n 58-718. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    109. http://www.pimaair.org/visit/aircraft-by-name/item/sikorsky-vh-34c-choctaw "Choctaw."
    110. Web site: Airframe Dossier –Sikorsky CH-34A, s/n 57-1698 USAF, c/n 58-0842, c/r N94485. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    111. Web site: Airframe Dossier – Sikorsky CH-34C Choctaw, s/n 57-1705 US. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    112. Web site: H-34 Choctaw Helicopter. Pacific Coast Air Museum. 29 October 2016. dead. https://web.archive.org/web/20161021145825/http://www.pacificcoastairmuseum.org/aircraft/H34Choctaw.asp. 21 October 2016.
    113. Web site: Airframe Dossier – SikorskyS-58 / H-34 / HSS / Wessex, s/n 57-1708 USAF, c/n 58-0868. Aerial Visuals. AerialVisuals.ca. 29 October 2016.
    114. Web site: THE EXECUTIVE FLIGHT DETACHMENT. US Army Transportation Museum. 29 October 2016. dead. https://web.archive.org/web/20161026204625/http://www.transportation.army.mil/museum/transportation%20museum/executiveflight.htm. 26 October 2016.
    115. Web site: Airframe Dossier – Sikorsky VH-34C, s/n 57-1725 US, c/n 58-0910. Aerial Visuals. AerialVisuals.ca. 29 October 2016.