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{{short description|American military transport helicopter family}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page
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{{Use American English|date=March 2023}}
[[Image:CH21B.jpg|thumb|250px|[[USAF]] CH-21B at the [[National Museum of the United States Air Force]]]]
{{Infobox aircraft
[[Image:Shawnees over south vietnam 1962.gif|thumb|right|150px|Shawnees in formation over [[South Vietnam]] in [[1962 in aviation|1962]]]]
|name= H-21 Shawnee/Workhorse
[[Image:Color_shawnee_over_rice_paddies.jpg|thumb|right|150px|A Shawnee over rice paddies in [[Vietnam]]]]
|image=Piasecki H-21 (modified).jpg
The '''H-21 Shawnee''' was the fourth of a line of tandem rotor helicopters designed and built by [[Piasecki]] (later [[Boeing Vertol]]). Commonly called the "flying banana", it was a multi-mission helicopter, utilizing wheels, skis, or floats. It was used for [[Arctic]] rescue because it performed so well at low temperatures. The CH-21 served with the [[United States Army]] from [[1949 in aviation|1949]] to [[1964 in aviation|1964]], and also with the [[USAF|U.S. Air Force]] (as the '''H-21 Workhorse'''), the [[French Navy]], the [[Royal Canadian Air Force]] and the [[German Air Force|West German Air Force]]. The [[France|French]] used an armed version of the CH-21 in [[Algeria]], mounting guns in the door ways and on the skids.
|caption=A [[US Army]] Piasecki H-21
|type=[[Military transport helicopter]]
|manufacturer= [[Piasecki Helicopter]]
|national_origin=United States
|designer=
|first_flight=11 April 1952
|introduction=
|retired=1967
|status= Retired
|primary_user=[[United States Air Force]]
|more_users=[[United States Army]]<br />[[French Army Light Aviation]]
|produced= 1952–1959
|number_built=
|developed_from=[[Piasecki HRP Rescuer]]
|variants=
}}


The '''Piasecki H-21 Workhorse/Shawnee''' is an American helicopter, the fourth of a line of [[tandem rotor]] helicopters designed and built by [[Piasecki Helicopter]] (later [[Boeing Vertol]]). Commonly called "the flying banana", it was a multi-mission helicopter, capable of being fitted with wheels, skis or floats.
The '''CH-21B''' assault helicopter could carry 22 fully-equipped troops, or 12 stretchers, plus space for two medical attendants, in the MedEvac role. The CH-21B was first deployed to [[Vietnam]] in [[December]] [[1961 in aviation|1961]] with the Army's 8th and 57th Transportation Companies, in support of ARVN (Army Vietnam) troops. The CH-21B/CH-21C Shawnee could be armed with 7.62 mm (.308 in) or 12.7 mm (.50 in) door guns. The CH-21 was relatively slow. Its cables and fuel lines were so vulnerable to small arms fire it was even rumored that a CH-21 had been downed by a [[Viet Cong]] spear. The Shawnee was the "Workhorse" of Vietnam until it was replaced with the fielding of the [[UH-1 Huey]], and the later fielding of the [[CH-47 Chinook]] in the mid-1960s. The Shawnee had two tandem fully-articulated three-bladed counter-rotating rotors. The CH-21 was powered by one Curtis-Wright R1820-103 Cyclone supercharged 1150 hp [[Four-stroke cycle|piston engine]]. The CH-21B was equipped with an uprated 1425 shaft [[horsepower]] (1063 kW) engine.

The CH-21 had a top speed of 128 mph (111 knots).
The H-21 was originally developed by Piasecki as an Arctic rescue helicopter. The H-21 had cold-weather features permitting operation at temperatures as low as {{cvt|-65|°F|°C|}} and could be routinely maintained in severe cold weather environments.

==Design and development==
[[File:Piasecki H-21 - Cockpit.jpg|thumb|Piasecki H-21 cockpit]]

Piasecki Helicopter designed and successfully sold to the [[United States Navy]] a series of tandem rotor helicopters, starting with the [[Piasecki HRP-1|HRP-1]] of 1944. The HRP-1 was nicknamed the "flying banana" because of the upward angle of the aft fuselage, which ensured that the large rotors could not strike the fuselage in any flight attitude. The name was later applied to other Piasecki helicopters of similar design, including the H-21.

In 1949, Piasecki proposed the YH-21 ''Workhorse'', which was an improved, all-metal derivative of the HRP-1, to the United States Air Force (USAF). Using two tandem, fully articulated three-bladed counter-rotating rotors, the H-21 was powered by one nine-cylinder [[Wright R-1820|Curtis-Wright R-1820-103 Cyclone]] supercharged {{cvt|1,150|hp|kW|0}} [[air-cooled]] [[radial engine]].

After the first flight of the YH-21 on 11 April 1952, the USAF ordered 32 H-21A SAR models and 163 of the more powerful H-21B assault transport variant.<ref name="jawa52p30">Bridgman 1952, p. 30.</ref> The H-21B was equipped with an uprated version of the Wright 103 engine, developing 1,425 [[shaft horsepower]] (1,063&nbsp;kW) and featured rotor blades extended by 6&nbsp;inches (152&nbsp;mm). With its improved capabilities, the '''H-21B''' could carry 22 fully equipped infantrymen or 12 stretchers, plus space for two medical attendants, as a [[Medical evacuation|medevac]] helicopter. With its Arctic winter capabilities, the H-21A and H-21B were put into service by the USAF and the Royal Canadian Air Force (RCAF) to maintain and service [[Distant Early Warning Line]] (DEW) radar installations stretching from the [[Aleutian Islands]] and [[Alaska]] across the [[Northern Canada|Canadian Arctic]] to [[Greenland]] and [[Iceland]].

[[File:Piasecki H-21 - inside.jpg|thumb|left|Piasecki H-21 cabin interior looking towards the cockpit]]
In 1952, some H-21As were evaluated by USMC helicopter squadron [[HMX-1]] for air assault.<ref>[https://books.google.com/books?id=ytwDAAAAMBAJ&dq=1954+Popular+Mechanics+January&pg=PA101 "Here Comes the Leathernecks."] ''Popular Mechanics'', April 1952, p. 101, bottom of page.</ref> In 1957, an H-21B was loaned to the [[United States Marine Corps]] (USMC) to evaluate the helicopter as an airborne tug to tow disabled landing ships and amphibious landing vehicles to the beach. During the evaluation, the H-21B towed an [[Landing Ship, Tank|LST]] at {{cvt|5|kn}} and a simulated tracked amphibious vehicle from the water to the beach.<ref>[https://books.google.com/books?id=DOEDAAAAMBAJ&dq=true&pg=PA106 "Flying Salvage Craft Works on Land Or Sea."] ''Popular Mechanics'', July 1957, p. 106</ref> The uprated 1425&nbsp;hp Wright engine used in the H-21B was also used in subsequent variants sold to both the U.S. Army (as the H-21C ''Shawnee'') and the military forces of several other nations. In 1962, the H-21 was renamed the CH-21 in U.S. Army service.

In 1959 Vertol Aircraft, the new name for Piasecki Helicopters, came up with a concept for heavy lift over short distances where between two and six H-21Bs would be linked by beams to lift heavy loads. It was considered to be unsafe, because if one helicopter had mechanical problems during the lift it could unbalance the structure and cause all helicopters to crash.<ref>[https://books.google.com/books?id=vtsDAAAAMBAJ&dq=true&pg=PA100 "Workhorses of the Air."] ''Popular Mechanics'', March 1959, p. 100.</ref>

==Operational history==

===French service in the Algerian War===

[[File:Color shawnee over rice paddies.jpg|thumb|A Shawnee over rice paddies in [[Vietnam]]]]
In 1956, seeking a way to use helicopters for ground-attack in the [[Algerian War of Independence|Algerian War]], the French Air Force and French Army Aviation ([[French Army Light Aviation|''Aviation Légère de l'Armée de Terre'']]) experimented with arming the [[Sikorsky H-19 Chickasaw|Sikorsky S-55]], then being superseded in service by the more capable Piasecki H-21 and [[Sikorsky H-34]] helicopters. Some French Air Force and Army aviation H-21C helicopters were subsequently armed with fixed, forward-firing rockets and machine guns. A few even had racks for bombs but tests found that the H-21C lacked the maneuverability and performance needed for ground-attack. The H-21C was far more successful as a troop transport, and most H-21Cs in service were eventually fitted with flexible door-mounted guns such as the .50 cal. (12.7&nbsp;mm) [[M2 Browning machine gun]] or the (ex-[[Nazi Germany|German]]) [[MG 151 cannon|MG 151/20]] 20&nbsp;mm aircraft autocannon, for defensive use when landing assault forces under fire.<ref name="France, Operations Research Group 1959">France, Operations Research Group, ''Report of the Operations Research Mission on H-21 Helicopter'' (1959)</ref><ref name="Riley, David 1958, pp. 21-26">Riley, David, ''French Helicopter Operations in Algeria'', Marine Corps Gazette, February 1958, pp. 21-26</ref><ref name="Shrader, Charles R. 1999">Shrader, Charles R. ''The First Helicopter War: Logistics and Mobility in Algeria, 1954-1962'' Westport, CT: Praeger Publishers (1999)</ref>

Though the H-21 had been removed from ground-attack, official U.S. Army evaluations at the time indicated that the type was actually more likely to survive hits by ground fire than was the Sikorsky CH-34; this was assumed to be a consequence of the location and construction of the CH-34's fuel tanks. By the close of the Algerian War, troop-carrying H-21C helicopters were being used in concert with H-34 ground-attack helicopters in large counterinsurgency operations.<ref name="France, Operations Research Group 1959"/><ref name="Riley, David 1958, pp. 21-26"/><ref name="Shrader, Charles R. 1999"/>

===U.S. Army operations===

The H-21C saw extensive service with the U.S. Army, primarily for use in transporting troops and supplies. On 24 August 1954, with the assistance of inflight refueling provided by a U.S. Army [[de Havilland Canada DHC-3 Otter|U-1A Otter]], a H-21C known as ''Amblin' Annie'' became the first helicopter to cross the United States non-stop.<ref>''The New Propwash'', Fox Valley Sport Aviation Assoc., Vol.2, Issue 12, p. 5</ref><ref>{{cite web |url=https://www.boeing.com/history/products/ch-21-shawnee-vertol-44-helicopter.page |title = Boeing: Historical Snapshot: CH-21 Shawnee/Vertol 44 Helicopter}}</ref> Experiments were made by the Army in arming the H-21C as a gunship; some Shawnees were armed with flex guns under the nose, while others were fitted with door guns.

[[File:H-21 Shawnees Fort Bragg 1956.png|thumb|left|H-21 Shawnees of the 8th Transportation Company, Ft Bragg, 1956. The company had 24 helicopters, 48 officers and warrant officers, and 246 enlisted men.]]

One experimental version was tested with a [[Boeing B-29 Superfortress]] .50 cal. remote turret mounted beneath the nose. The H-21C (later designated CH-21C) was first deployed to [[South Vietnam]] in December 1961 with the Army's 8th and 57th Transportation Companies, in support of [[Army of the Republic of Vietnam]] troops. In Army service, the CH-21C Shawnee could be armed with 7.62&nbsp;mm (.308 in) or 12.7&nbsp;mm (.50 in) flexible door guns. Relatively slow, the CH-21's unprotected control cables and fuel lines proved vulnerable to the [[Vietcong]], which were increasingly well supplied with automatic small arms and heavy (12.7&nbsp;mm) anti-aircraft machine guns.

The H-21, which was designed for cold weather operations, performed poorly in the hot weather of Vietnam. Despite being capable of carrying 20 passengers, it could lift only nine when operating in Vietnam. Pilots reported that engines that were rated for 600 hours of flying time were lasting only 200 hours or less in Vietnam.<ref>{{cite news | title= Army Copter Pilots in Vietnam Say H-21's Are Not Adequate | last = Halberstam | first = David | work = The New York Times | date = 19 January 1963 | page = 3 | url = https://timesmachine.nytimes.com/timesmachine/1963/01/19/issue.html | access-date = 3 May 2019 | url-access=subscription}}</ref> The shooting down of a CH-21 Shawnee near the Laotian-Vietnamese border with the death of four aviators in July 1962 were some of the U.S. Army's earliest casualties in the [[Vietnam War]].<ref name="Harding p261-2">Harding 1990, pp. 261–262.</ref> Despite these events, the Shawnee continued in service as the U.S. Army's helicopter workhorse in Vietnam until 1964 when it was replaced with the [[Bell UH-1 Iroquois|Bell UH-1 Huey]]. In 1965, the [[Boeing CH-47 Chinook]] was deployed to Vietnam and later that year, most CH-21 helicopters were withdrawn from active inventory in the U.S. Army and Air Force.

==Variants==
;XH-21
:USAF designation of the first H-21 prototype.
;YH-21 Work Horse
:USAF Search And Rescue (SAR) version of the HRP-2 for service test, eighteen built
;H-21A Work Horse (Model 42)
:Same as YH-21 with detailed changes and powered by one 1250hp [[Wright R-1820]]-102, re-designated CH-21A in 1962, 32 built for USAF, 6 for the Royal Canadian Air Force
;H-21B Work Horse (Model 42)
:Same as H-21A but with uprated Wright engine (1425hp) and seats for 20 troops, autopilot as standard and limited armour protection and external fuel tanks, became CH-21B in 1962, 163 built for U.S. forces. 10 built for [[Japanese Self-Defense Force]]s; 10 H-21B built for the [[French Navy]].
;SH-21B Work Horse
:Rescue conversion of the H-21B, became HH-21B in 1962.
;H-21C Shawnee (Model 43)
:US Army version of the H-21B, became CH-21C in 1962, 334 built for U.S. forces. 32 built under license by Weser Flugzeugbau for the West German Army. 98 built for the [[French Air Force]] and [[French Army Light Aviation|French Army Aviation]] (ALAT).
;XH-21D Shawnee (Model 71).
:Two H-21Cs re-engined with two [[General Electric T58]] turboshaft engines in place of the Wright R-1820. Not placed into production.
;CH-21A
:H-21A redesignated in 1962.
;CH-21B
:H-21B redesignated in 1962.
;CH-21C
:H-21C redesignated in 1962.
;HH-21B
:SH-21B redesignated in 1962.
;Model 42A
:Conversion by Vertol Aircraft (Canada) of eight Royal Canadian Air Force H-21s for civilian use. Equipped to carry 19 passengers or 2,820lb (1,279kg) of internal cargo or a 5,000lb (2,268kg) slung load.
;Model 44A
:Commercial 19-passenger transport version of the H-21B. 11 total (Swedish military designation: Hkp 1), 2 for the [[Swedish Air Force]], 9 for the [[Swedish Navy]]. 2 used for test/evaluation purposes by Japan Self-Defense Forces.
;Model 44B
:Commercial 15-passenger/freighter version of the H-21B.
;Model 44C
:Commercial eight-passenger executive version of the H-21B.
;CH-127
:Vertol Canada Model 44
;Piasecki HkP1
:Piasecki model 44 for the Swedish Navy

==Operators==
[[File:US Army H-21 in flight.jpg|thumb|right|A [[US Army]] H-21 in flight]]

===Military operators===
;{{flagcountry|CAN|1921}}
* [[Royal Canadian Air Force]]<ref>{{cite web|url= https://www.flightglobal.com/pdfarchive/view/1955/1955%20-%200621.html |title= World Air Forces 1955 pg. 621 |publisher= flightglobal.com |access-date=4 August 2018}}</ref>
;{{COD}}
* [[Air Force of the Democratic Republic of the Congo|Congo Democratic Air Force]]<ref name=trade>{{cite web |url=http://armstrade.sipri.org/armstrade/page/trade_register.php |title=Trade Registers |publisher=Armstrade.sipri.org |access-date=3 February 2019 |archive-date=14 April 2010 |archive-url=https://web.archive.org/web/20100414022558/http://armstrade.sipri.org/armstrade/page/trade_register.php |url-status=dead }}</ref>
;{{FRA}}
* [[French Air Force]]<ref>Arkell ''Flight'' 21 June 1957, p. 844.</ref>
* [[French Army Light Aviation|French Army]]<ref>{{cite web|url= https://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201258.html|title= World Helicopter Market 1967 pg. 60 |publisher= flightglobal.com |access-date=4 August 2016}}</ref>
[[File:Piasecki H-21 - left.jpg|thumb|right|Hkp 1 in [[Swedish Navy]] markings]]
* [[French Navy]]<ref>{{cite web|url=http://www.helis.com/database/modelorg/649/ |title=aéronautique navale H-21 |publisher= helis.com|access-date=5 January 2013}}</ref>
;{{Flagcountry|JPN|1947}}
* [[Japan Air Self-Defense Force]]<ref name=" World Helicopter Market 1967 pg. 62 ">{{cite web |url= https://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201260.html|title = World Helicopter Market 1967 pg. 62 |publisher= Flightglobal Insight |year= 2018 |access-date= 4 August 2018}}</ref>
* [[Japan Ground Self-Defense Force]]<ref name=" World Helicopter Market 1967 pg. 62 "/>
;{{SWE}}
* [[Swedish Navy]]<ref>{{cite web|url= https://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201263.html|title= World Helicopter Market 1967 pg. 65 |publisher= flightglobal.com |access-date=4 August 2016}}</ref>
;{{flag|United States|1959}}
* [[United States Air Force]]<ref>Swanborough and Bowers 1963, pp. 398–399.</ref>
* [[United States Army]]<ref>''Flight'' 13 May 1955, p. 668.</ref>
[[File:USAF H-21 manual.jpg|thumb|right|An HH-21 with US Air Force]]
;{{Flagcountry|FRG}}
* [[German Army]]<ref>{{cite web|url= https://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201259.html|title= World Helicopter Market 1967 pg. 61 |publisher= flightglobal.com |access-date=4 August 2016}}</ref>

===Civil operators===
;{{flag|United States|1912}}
* [[New York Airways]]<ref>{{cite web|url= http://www.flightglobal.com/pdfarchive/view/1958/1958%20-%200372.html|title= Helicopters in Civil Operations pg. 388|publisher= flightglobal.com |date=21 March 1958|access-date=10 February 2015}}</ref>

==Aircraft on display==

===Canada===
* 642 – On display at the [[Musée de la Défense aérienne]] of [[CFB Bagotville]], [[Quebec]]<ref>{{cite web|url=http://silverhawkauthor.com/aircraft-preserved-in-canada-6-warplanes-in-quebec_389.html|title=Harold A. Skaarup, author of Shelldrake|website=silverhawkauthor.com|access-date=6 January 2019|archive-date=6 January 2019|archive-url=https://web.archive.org/web/20190106153330/http://silverhawkauthor.com/aircraft-preserved-in-canada-6-warplanes-in-quebec_389.html|url-status=dead}}</ref>
* 641 – On display at the Heritage Air Park of the [[Comox Air Force Museum]] [[CFB Comox]], [[British Columbia]]<ref>{{cite web|url=https://comoxairforcemuseum.ca/wp-content/uploads/Guide-to-the-Aircraft-of-CAFM-Heritage-Air-Park.pdf|title=Guide to the Aircraft of the CAFM Heritage Air Park|access-date=2022-09-03}}</ref>

===France===
[[File:Vertol CH-21B Workhorse USAF.jpg|thumb|right|A [[USAF]] CH-21B at the [[National Museum of the United States Air Force]]
]]
* FR94 – H-21C on static display at the Musée de l'Aviation Légere de l'Armée de Terre et de l'Hélicoptère in [[Dax, Landes]].<ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol H-21C-PH Shawnee, s/n FR94 AdT, c/n FR94|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=125745|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* FR106 is on display at the "Ailes Anciennes" Museum at Toulouse-Blagnac Airport.<ref>{{cite web|url=http://www.aatlse.org/?coll=h21|title=Ailes Anciennes Toulouse|work=aatlse.org|access-date=23 November 2016}}</ref>

===Germany===
* 83+07 – H-21C on static display at the [[Hubschraubermuseum Bückeburg]] in [[Bückeburg|Bückeburg, Lower Saxony]].<ref>{{cite web|title=Vertol V-43 (H-21C)|url=http://www.hubschraubermuseum.de/exponate/mehrrotorige-hubschrauber/vertol-v-43-h-21c/?lang=en|website=Das Hubschraubermuseum Bückeburg|access-date=21 October 2016}}{{Dead link|date=August 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 83+07 Heeresfliegertruppe, c/n WG7|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=21366|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 83+08 – H-21C on static display at the [[Militärhistorisches Museum Flugplatz Berlin-Gatow]] in [[Berlin, Berlin]].<ref>{{cite web|title=Transporthubschauber Vertol (Piasecki) V-43A (H-21C) (Luftfahrzeugkennung der Bundeswehr: 83+08)|url=http://www.museum-digital.de/berlin/index.php?t=objekt&suinin=12&extern=yes&exWho=12&oges=902|website=Militärhistorische Museum der Bundeswehr Flugplatz Berlin Gatow|access-date=20 October 2016|language=de|date=2 January 2016}}</ref>
* 83+11 – H-21C on static display at the [[Flugausstellung Hermeskeil]] in [[Hermeskeil|Hermeskeil, Rhineland-Palatinate]].<ref>{{cite web|title=Flugzeuge|url=http://www.flugausstellung.de/flugzeuge.html|website=Flugausstellung|access-date=21 October 2016|url-status=dead|archive-url=https://web.archive.org/web/20151231084758/http://www.flugausstellung.de/flugzeuge.html|archive-date=31 December 2015}}</ref>
* 83+17 – XH-21D on static display at the [[Auto & Technik Museum Sinsheim]] in [[Sinsheim|Sinsheim, Baden-Württemberg]].<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 83+17 Luftwaffe, c/n WG17|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=39168|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>

===Japan===
* JG-0001 – Model 44A on static display at the [[Bihoro Aviation Park]] in [[Bihoro, Hokkaido]].<ref name="JHS-JGSDF">{{cite web|last1=Thompson|first1=Paul|title=JGSDF – Where Are They Now?|url=http://www.j-hangarspace.jp/jgsdf-where-are-they-now|website=J-Hangar Space|publisher=J-HangarSpace|access-date=21 October 2016}}</ref>
* JG-0002 – Model 44A on static display at the [[Tokorozawa Aviation Museum]] in [[Tokorozawa, Saitama]].<ref>{{cite web|title=Experience Exhibits|url=http://tam-web.jsf.or.jp/contxe/modules/tinyd3/index.php?id=2|website=Tokorozawa Aviation Museum|access-date=21 October 2016|url-status=dead|archive-url=https://web.archive.org/web/20160314120633/http://tam-web.jsf.or.jp/contxe/modules/tinyd3/index.php?id=2|archive-date=14 March 2016}}</ref><ref>{{cite web|title=Airframe Dossier – Piasecki 44A, s/n 50002 JASDF, c/n 44-20|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=151837|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref><ref name="JHS-JGSDF"/>
* 02-4756 – H-21B on static display at the JASDF Air Park in [[Hamamatsu, Shizuoka]].<ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol CH-21B Work Horse, s/n 02-4756 JASDF, c/n B148|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=151658|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref><ref>{{cite web|last1=Thompson|first1=Paul|title=JASDF – Where Are They Now?|url=http://www.j-hangarspace.jp/jasdf-where-are-they-now|website=J-HangarSpace|access-date=21 October 2016}}</ref>

===Russia===
* N74056 – Model 44A on static display at [[Central Air Force Museum]] in [[Monino|Monino, Moscow]].<ref>{{cite web|title=Airframe Dossier – Piasecki 44C, c/n 44-417, c/r N74056|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=145990|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>

===Sweden===
* 01001 – HKP 1 on static display at the [[Swedish Air Force Museum]] in [[Linköping|Linköping, Östergötland]].<ref>{{cite web |url=http://www.flygvapenmuseum.se/sv/Foremal--Fakta/Foremal/Flygplan/Utstallda/Flygplan-teknikutveckling/Hkp-1/ |title=Hkp 1 |date=21 April 2010 |website=flygvapenmuseum.se |publisher=Statens Försvarshistoriska museeer |location=Linköping |language=sv |access-date=21 October 2016 |archive-url=https://web.archive.org/web/20100813031129/http://www.flygvapenmuseum.se/sv/Foremal--Fakta/Foremal/Flygplan/Utstallda/Flygplan-teknikutveckling/Hkp-1 |archive-date=13 August 2010}}</ref>
* 01009 – HKP 1 on static display at the Gotland Museum of Defence in [[Tingstäde]], [[Gotland]].<ref>{{cite web |url=https://digitaltmuseum.org/021027327417/helikopter?aq=topic:%22Helikopter%22&i=11 |title=Helikopter – Gotlands Försvarsmuseum |date=18 October 2017 |website=digitaltmuseum.org |location=Tingstäde |publisher=Gotlands Forsvarsmuseum |language=sv |access-date=27 July 2020|archive-url= https://archive.today/20200727143433/https://digitaltmuseum.org/021027327417/helikopter?aq=topic:%22Helikopter%22&i=11|archive-date= 27 July 2020|url-status= live}}</ref>

===United States===
;Airworthy
* 54-4001 – CH-21B airworthy at the [[Classic Rotors Museum]] in [[Ramona, California]]. This is the last H-21 still flown.<ref>{{cite web|title=Vertol H-21 Shawnee/Work Horse|url=http://www.rotors.org/h21/21.htm|website=Classic Rotors|access-date=20 October 2016|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303184235/http://www.rotors.org/h21/21.htm|url-status=dead}}</ref><ref>{{cite web|title=FAA REGISTRY [N64606]|url=http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=N64606|website=Federal Aviation Administration|publisher=U.S. Department of Transportation|access-date=20 October 2016|archive-date=29 February 2012|archive-url=https://web.archive.org/web/20120229091551/http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=N64606|url-status=dead}}</ref>

;Static Display
[[File:JGSDF V-44A.JPG|thumb|right|Model 44A with the [[JGSDF]] at [[Bihoro Aviation Park]], August 2009]]
* 51-15857 – CH-21B on static display at the [[National Museum of the United States Air Force]] at [[Wright-Patterson AFB]] in [[Dayton, Ohio]]. It was obtained from [[Eglin Air Force Base]] in January 1965.<ref>{{cite web|title=Vertol CH-21B Workhorse|url=http://www.nationalmuseum.af.mil/Visit/MuseumExhibits/FactSheets/Display/tabid/509/Article/198068/vertol-ch-21b-workhorse.aspx|website=National Museum of the US Air Force|access-date=20 October 2016|date=29 May 2015}}</ref>
* 51-15859 – CH-21B on static display at [[Battleship Memorial Park]] in [[Mobile, Alabama]].<ref>{{cite web|title=AIRCRAFT COLLECTION|url=http://www.ussalabama.com/uss-aircraft-collection|website=Battleship Memorial Park|publisher=USS ALABAMA|access-date=20 October 2016|url-status=dead|archive-url=https://web.archive.org/web/20160728133844/http://www.ussalabama.com/uss-aircraft-collection|archive-date=28 July 2016}}</ref><ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol CH-21B Work Horse, s/n 51-15859 USAF, c/n B.6|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=83854|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 51-15886 – CH-21C on static display at the [[Aerospace Museum of California]] at [[McClellan Airport]] (former [[McClellan AFB]]) in [[McClellan, California]].<ref>{{cite web|title=Airframe Dossier – Piasecki CH-21C Shawnee, s/n 51-15886 US, c/r N48082|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=35818|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 51-15892 – CH-21B on static display at the [[Quonset Air Museum]] at the former [[Naval Air Station Quonset Point]] in [[North Kingstown, Rhode Island]].<ref>{{cite web|last1=Carroll|first1=Sean|title=[Untitled]|url=http://www.geocities.ws/scc261/892_1.html|access-date=21 October 2016}}</ref>
* 52-8676 – CH-21B on static display at the [[Strategic Air Command & Aerospace Museum]] near [[Offutt AFB]] in [[Ashland, Nebraska]].<ref>{{cite web|title=CH-21B "Work Horse"|url=http://sacmuseum.org/what-to-see/aircraft/ch-21b-work-horse|website=Strategic Air Command & Aerospace Museum|access-date=20 October 2016}}</ref>
* 52-8685 – CH-21B on static display at the [[Museum of Aviation (Warner Robins)|Museum of Aviation]] at [[Robins AFB]] near [[Warner Robins, Georgia]].<ref>{{cite web|title=CH-21B "Workhorse"|url=http://www.museumofaviation.net/?artwork=ch-21b-workhorse|website=Museum of Aviation|access-date=20 October 2016}}</ref>
* 52-8688 – CH-21B on static display at the [[Travis Air Force Base Heritage Center]] near [[Fairfield, California]].<ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol H-21B Work Horse, s/n 52-8688 USAF, c/r N6795|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=12811|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 52-8691/52-8706 – CH-21B on static display at [[Kirtland Air Force Base]] in [[Albuquerque, New Mexico]]. This airframe is a composite of two different airframes and is painted as 53-4343.<ref>{{cite web|title=Airframe Dossier – Piasecki UH-21B Work Horse, s/n 52-8691 USAF|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=50745|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 52-8696 – CH-21B on static display at [[Joint Base Elmendorf-Richardson]] near [[Anchorage, Alaska]].<ref>{{cite web|title=Heritage Park Tour Briefing|url=http://www.matsuk12.us/cms/lib/AK01000953/Centricity/Domain/3581/Heritage%20Park%20Information.pdf|website=Matanuska-Susitna Borough School District|access-date=21 October 2016|date=May 2007}}</ref>
* 53-4323 – HH-21B on static display at Berryman War Memorial Park in [[Bridgeport, Washington]].<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 53-4323 USAF, c/n B.73, c/r N6793|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=278|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 53-4324 – CH-21B on static display at the [[Vintage Flying Museum]] in [[Fort Worth, Texas]].<ref>{{cite web|title=Piasecki CH-21B Workhorse|url=http://vintageflyingmuseum.org/on-display/piasecki-ch-21b-workhorse|website=Vintage Flying Museum|access-date=20 October 2016}}</ref> This airframe was previously on display at the Pate Museum of Transportation in [[Cresson, Texas]].<ref>{{cite web|title=Airframe Dossier – Piasecki CH-21B Work Horse, s/n 53-4324 USAF, c/n B74|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=28550|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 53-4326 – CH-21B on static display at the [[March Field Air Museum]] at [[March Air Reserve Base]] (former [[March AFB]]) in [[Riverside, California]].<ref>{{cite web|title=H-21 Workhorse|url=http://www.marchfield.org/aircraft/helicopter/h-21b-workhorse-piasecki|website=March Field Air Museum|access-date=20 October 2016|archive-date=21 October 2016|archive-url=https://web.archive.org/web/20161021131424/http://www.marchfield.org/aircraft/helicopter/h-21b-workhorse-piasecki/|url-status=dead}}</ref>
* 53-4347 – CH-21B on static display at the [[Pueblo Weisbrod Aircraft Museum]] in [[Pueblo, Colorado]].<ref>{{cite web|title=Actual Aircraft Aircraft on Display in Pueblo|url=http://www.pwam.org/aircraftdisplay1.html|website=Pueblo Weisbrod Aircraft Museum|access-date=20 October 2016|url-status=dead|archive-url=https://web.archive.org/web/20161225043629/http://www.pwam.org/aircraftdisplay1.html|archive-date=25 December 2016}}</ref><ref>{{cite web|title=Aircraft 53-4347 Data|url=http://www.airport-data.com/aircraft/53-4347.html|website=Airport-Data.com|access-date=20 October 2016}}</ref>
* 53-4354 – CH-21C on static display at the [[Arkansas Air & Military Museum]] in [[Fayetteville, Arkansas]].<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 53-4354 USAF|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=1875|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=8 November 2016}}</ref>
* 53-4362 – SH-21B on static display at the Alaska Museum of Transportation and Industry in [[Wasilla, Alaska]].<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 53-4362|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=13024|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 53-4366 – CH-21B on static display at the [[Museum of Flight]] in [[Seattle]], Washington.<ref>{{cite web|title=Piasecki H-21B (CH-21B) Workhorse|url=http://www.museumofflight.org/aircraft/piasecki-h-21b-ch-21b-workhorse|website=The Museum of Flight|access-date=20 October 2016}}</ref>
* 53-4367 – CH-21B on static display at the [[Mid-Atlantic Air Museum]], [[Reading, Pennsylvania]].<ref>{{cite web|title=Aircraft of the Mid-Atlantic Air Museum|url=http://www.maam.org/aircraft.htm|website=Mid-Atlantic Air Museum|access-date=20 October 2016|archive-date=7 June 2012|archive-url=https://web.archive.org/web/20120607004015/http://www.maam.org/aircraft.htm|url-status=dead}}</ref>
* 53-4369 – CH-21B on static display at the [[United States Army Aviation Museum]] near [[Fort Novosel]] in [[Daleville, Alabama]].<ref>{{cite web|title=Airframe Dossier – Piasecki HH-21B Work Horse, s/n 53-4369 US, c/r N109RB|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=16983|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 53-4389 – CH-21B on static display at the [[Pima Air & Space Museum]] adjacent to [[Davis-Monthan AFB]] in [[Tucson, Arizona]].<ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol CH-21B Work Horse, s/n 53-4389 USAF, c/n B.139|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=57786|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 54-4404 – CH-21B on static display at the [[Alaska Aviation Heritage Museum]] in [[Anchorage, Alaska]].<ref>{{cite web|title=Airframe Dossier – Piasecki H-21B Work Horse, s/n 54-4004 USAF|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=9489|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 55-4140 – CH-21C on static display at the American Helicopter Museum & Education Center in West Chester, Pennsylvania.<ref>{{cite web|title=Piasecki H-21 / CH 21B Workhorse|url=http://americanhelicopter.museum/aircraft/piasecki-h-21-ch-21b-workhorse|website=American Helicopter Museum & Education Center|access-date=21 October 2016|url-status=dead|archive-url=https://web.archive.org/web/20161021070924/http://americanhelicopter.museum/aircraft/piasecki-h-21-ch-21b-workhorse|archive-date=21 October 2016}}</ref> This airframe was previously on display at the [[Intrepid Sea, Air & Space Museum]] in [[New York, New York]].<ref>{{cite web|title=Airframe Dossier – Piasecki CH-21C Shawnee, s/n 55-4140 US, c/n C.94|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=60105|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 55-4218 – CH-21C on static display at the [[Evergreen Aviation & Space Museum]] in [[McMinnville, Oregon]].<ref>{{cite web|title=Helicopters|url=http://www.evergreenmuseum.org/helicopters|website=Evergreen Museum Campus|publisher=Evergreen Museum|access-date=20 October 2016|archive-date=31 May 2017|archive-url=https://web.archive.org/web/20170531024716/http://www.evergreenmuseum.org/helicopters|url-status=dead}}</ref> This airframe was previously on display at the [[Wings Over the Rockies Air and Space Museum]] at the former [[Lowry AFB]] in [[Denver]], Colorado. It is painted as 53-4379.<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 55-4218 US Army|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=35837|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=20 October 2016}}</ref>
* 56-2040 – CH-21C on static display at the United States Army Aviation Museum at Fort Novosel, near Daleville, Alabama.<ref>{{cite web|title=Airframe Dossier – Piasecki CH-21C Shawnee, s/n 56-2040 US, c/n C.202|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=12560|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 56-2077 – CH-21C on static display at the [[U.S. Army Transportation Museum]] ay [[Fort Eustis]] near [[Newport News, Virginia]].<ref>{{cite web|title=Airframe Dossier – Piasecki CH-21C Shawnee, s/n 56-2077 US, c/n C.239|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=6397|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
[[File:Musée défense aérienne - Vertol H-21B.jpg|thumb|right|CH-21 in [[RCAF]] markings at the [[Canadian Museum of Flight]] ]]
* 56-2142 – CH-21C on static display at the [[Hill Aerospace Museum]] at [[Hill AFB]] near [[Ogden, Utah]]. This airframe is painted as 54-4002.<ref>{{cite web|title=CH-21C "Workhorse"|url=http://www.hill.af.mil/About-Us/Fact-Sheets/Display/Article/397285/ch-21c-workhorse|website=Hill Air Force Base|access-date=20 October 2016|date=27 September 2007|archive-date=19 October 2016|archive-url=https://web.archive.org/web/20161019071405/http://www.hill.af.mil/About-Us/Fact-Sheets/Display/Article/397285/ch-21c-workhorse|url-status=dead}}</ref>
* 56-2159 – CH-21C on static display at the [[Pima Air & Space Museum]] adjacent to [[Davis-Monthan AFB]] in [[Tucson, Arizona]].<ref>{{cite web|title=WORKHORSE|url=http://www.pimaair.org/aircraft-by-name/item/piasecki-vertol-ch-21c-workhorse|website=Pima Air & Space Museum|publisher=Pimaair.org|access-date=20 October 2016|archive-date=21 October 2016|archive-url=https://web.archive.org/web/20161021064504/http://www.pimaair.org/aircraft-by-name/item/piasecki-vertol-ch-21c-workhorse|url-status=dead}}</ref>
;Stored or under restoration
* 52-8623 – CH-21B in storage at the [[Air Force Flight Test Museum]] at [[Edwards AFB]] in [[Edwards, California]].<ref>{{cite web|title=Aircraft Inventory|url=http://afftcmuseum.org/exhibits/museum-aircraft-exhibits|website=Flight Test Historical Foundation|access-date=21 October 2016|archive-url=https://web.archive.org/web/20161019025925/http://afftcmuseum.org/exhibits/museum-aircraft-exhibits/|archive-date=19 October 2016|url-status=dead}}</ref>
* 52-8683 – H-21B in storage with [[Basler Turbo Conversions]] in [[Oshkosh, Wisconsin]].<ref>{{cite web|title=Airframe Dossier – Piasecki H-21B Work Horse, s/n 52-8683 USAF, c/n B.45, c/r N57968|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=37883|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 53-4329 – CH-21B under restoration at the [[Museum of Flight]] Restoration Center at [[Paine Field]] in [[Everett, Washington]].<ref>{{cite web|title=Airframe Dossier – PiaseckiH-21, s/n 53-4329 USAF, c/r N6794|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=30613|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* 54-4003 – CH-21B in storage at the [[American Helicopter Museum & Education Center]] in [[West Chester, Pennsylvania]]. This airframe was previously on display at the [[Florence Air & Missile Museum]] in [[Florence, South Carolina]].<ref>{{cite web|title=Airframe Dossier – Piasecki-Vertol H-21B Work Horse, s/n FR09 AdT, c/n B.155|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=65218|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=21 October 2016}}</ref>
* c/n 438 – Model 44B in storage in unrestored condition at the [[Gillespie Field#San Diego Air & Space Museum Gillespie Field Annex|Gillespie Field Annex]] of the [[San Diego Air & Space Museum]] in [[El Cajon, California]].<ref>{{cite web|title=Airframe Dossier – Piasecki 44B, c/r N74058|url=http://aerialvisuals.ca/AirframeDossier.php?Serial=11598|website=Aerial Visuals|publisher=AerialVisuals.ca|access-date=17 November 2016}}</ref>


==Specifications (CH-21C)==
==Specifications (CH-21C)==
[[File:Piasecki YH-21 Workhorse 3-view line drawing.png|frameless|right|3-view line drawing of the Piasecki YH-21 Workhorse]]
{{airtemp|

<!-- if you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] -->
{{Aircraft specs
<!-- please answer the following questions -->
|ref=U.S. Army Aircraft Since 1947<ref name="Harding p262">Harding 1990, p.262.</ref>
|plane or copter?=copter
|prime units?=imp
|jet or prop?=prop
<!--
<!-- Now, fill out the specs. Please include units where appropriate (main comes first, alt in parentheses). If an item doesn't apply, like capacity, leave it blank. For additional lines, end your alt units with )</li> and start a new, fully-formatted line with <li> -->
General characteristics
|crew=Two
-->
|capacity=22 troops or 12 stretchers
|crew=3–5 (Pilot, co-pilot, crew chief and one or two gunners in Vietnam)
|length main=52 ft 6 in
|capacity=
|length alt=16.00 m
** 20 troops ''or''
|span main=2x 44 ft 0 in
** 12 stretchers
|span alt=13.40 m
|length ft=52
|height main=15 ft 9 in
|length in=6
|height alt=4.80 m
|length note=
|area main=3,041 ft²
|height ft=15
|area alt=282.7 m²
|height in=9
|empty weight main=8,950 lb
|height note=
|empty weight alt=4,058 kg
|loaded weight main=15,200 lb
|empty weight lb=8950
|loaded weight alt=6,893 kg
|empty weight note=
|max takeoff weight main=lb
|gross weight lb=15200
|max takeoff weight alt= kg
|gross weight note=
|max takeoff weight lb=
|engine (prop)=[[Wright R-1820]]-103
|max takeoff weight note=
|type of prop=[[radial engine]]
|fuel capacity=
|number of props=1
|more general=
|power main=1,425 hp
<!--
|power alt=1,063 kW
Powerplant
|max speed main=127 mph
-->
|max speed alt=204 km/h
|eng1 number=1
|range main=265 miles
|eng1 name=[[Wright R-1820-103 Cyclone]]
|range alt=426 km
|eng1 type=9-cylinder air-cooled radial piston engine
|ceiling main=9,450 ft
|eng1 hp=1425
|ceiling alt=2,880 m
|eng1 note=
|climb rate main=ft/min

|climb rate alt= m/s
|rot number=2
|loading main=5 lb/ft²
|rot dia ft=44
|loading alt=24 kg/m²
|rot dia in=0
|power/mass main=0.09 hp/lb
|rot area sqft=3041
|power/mass alt=150 W/kg
|rot area note=
|armament=
* '''Blade section:''' – [[NACA airfoil|NACA 0012]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
* Varying, but usually twin or quad [[.50 BMG|.50]] (12.7 mm) [[machine gun]]s.
<!--
Performance
-->
|max speed mph=127
|max speed note=
|cruise speed mph=98
|cruise speed note=
|never exceed speed mph=
|never exceed speed note=
|range miles=265
|range note=
|combat range miles=
|combat range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=9450
|ceiling note=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|disk loading lb/sqft=5
|disk loading note=
|fuel consumption lb/mi=
|power/mass={{cvt|0.09|hp/lb}}
|more performance=
<!--
Armament
-->
|armament=* Varying, but usually one or two [[.50 BMG|.50]] (12.7 mm) machine-guns, or 7.62 mm [[M60 machine gun|M60]] [[machine gun]]s.
|avionics=
}}
}}


==Related content==
==See also==
{{Commons|H-21 Shawnee}}
{{Portal|Aviation}}
{{aircontent|
{{aircontent
|related=
|related=
[[HRP-2 Rescuer]]
* [[Piasecki HRP Rescuer]]
* [[Piasecki H-25]]

* [[Boeing Vertol CH-46 Sea Knight]]
* [[Boeing CH-47 Chinook]]
|similar aircraft=
|similar aircraft=
* [[Bristol Belvedere]]
* [[Yakovlev Yak-24]]
|sequence=
|sequence=
|lists=
[[UH-19 Chickasaw|UH-19]] -
* [[List of military aircraft of the United States]]
[[McDonnell XH-20|XH-20]] -
|see also=
[[Sikorsky YH-18|YH-18]] -
'''CH-21''' -
[[Kaman YH-22|YH-22]] -
[[OH-23 Raven|OH-23]] -
[[Siebel YH-24|YH-24]]

}}
}}


==References==
[[Category:Helicopters]]
{{reflist}}
[[Category:U.S. military transport aircraft 1940-1949]]
* Arkell, Basil. [https://www.flightglobal.com/pdfarchive/view/1957/1957%20-%200838.html "Helicopters in Contrast: (2) Flying the American Vertol 44"]. ''Flight'', Vol. 71, No. 2526. pp.&nbsp;844–846.
* Bridgman, Leonard. ''Jane's All the World's Aircraft 1952–53''. London: Sampson Low, Marston & Company, Ltd., 1952.
* Duke, R.A., ''Helicopter Operations in Algeria'' [Trans. French], Dept. of the Army (1959).
* Harding, Stephen. ''U.S. Army Aircraft Since 1947''. Shrewsbury, UK:Airlife Publishing, 1990. {{ISBN|1-85310-102-8}}.
* Swanborough, F. G. and [[Peter M. Bowers|Bowers, Peter M.]] ''United States Military Aircraft since 1909''. London: Putnam, 1963.
* [https://www.flightglobal.com/pdfarchive/view/1955/1955%20-%200615.html "The World's Air Forces"]. ''[[Flight International|Flight]]'', Vol. 67, No. 2416, 13 May 1955. pp.&nbsp;615–668.
* [https://www.flightglobal.com/pdfarchive/view/1968/1968%20-%201204.html "World Helicopter Market"]. ''Flight'', Vol. 94, No. 3096, 11 July 1968. pp.&nbsp;48–60.
* United States Air Force Museum (1975 edition)

==External links==
{{Commons|H-21 Shawnee}}
* [https://web.archive.org/web/20101105085538/http://www.redstone.army.mil/history/aviation/factsheets/ch21.html H-21 US Army Aviation history fact sheet]

{{Boeing Helicopters model numbers}}
{{Piasecki/Vertol aircraft}}
{{USAF helicopters}}
{{CF aircraft}}
{{Swedish military aircraft designations}}

{{Authority control}}


[[de:Piasecki H-21]]
[[Category:Piasecki Helicopter aircraft|H-021]]
[[Category:1950s United States military transport aircraft]]
[[Category:1950s United States helicopters]]
[[Category:Tandem rotor helicopters]]
[[Category:Single-engined piston helicopters]]
[[Category:United States military helicopters|Piasecki H-21 Shawnee Workhorse]]
[[Category:Aircraft first flown in 1952]]
[[Category:Historic American Engineering Record in Texas]]

Latest revision as of 19:19, 9 September 2024

H-21 Shawnee/Workhorse
A US Army Piasecki H-21
General information
TypeMilitary transport helicopter
National originUnited States
ManufacturerPiasecki Helicopter
StatusRetired
Primary usersUnited States Air Force
History
Manufactured1952–1959
First flight11 April 1952
Retired1967
Developed fromPiasecki HRP Rescuer

The Piasecki H-21 Workhorse/Shawnee is an American helicopter, the fourth of a line of tandem rotor helicopters designed and built by Piasecki Helicopter (later Boeing Vertol). Commonly called "the flying banana", it was a multi-mission helicopter, capable of being fitted with wheels, skis or floats.

The H-21 was originally developed by Piasecki as an Arctic rescue helicopter. The H-21 had cold-weather features permitting operation at temperatures as low as −65 °F (−54 °C) and could be routinely maintained in severe cold weather environments.

Design and development

[edit]
Piasecki H-21 cockpit

Piasecki Helicopter designed and successfully sold to the United States Navy a series of tandem rotor helicopters, starting with the HRP-1 of 1944. The HRP-1 was nicknamed the "flying banana" because of the upward angle of the aft fuselage, which ensured that the large rotors could not strike the fuselage in any flight attitude. The name was later applied to other Piasecki helicopters of similar design, including the H-21.

In 1949, Piasecki proposed the YH-21 Workhorse, which was an improved, all-metal derivative of the HRP-1, to the United States Air Force (USAF). Using two tandem, fully articulated three-bladed counter-rotating rotors, the H-21 was powered by one nine-cylinder Curtis-Wright R-1820-103 Cyclone supercharged 1,150 hp (858 kW) air-cooled radial engine.

After the first flight of the YH-21 on 11 April 1952, the USAF ordered 32 H-21A SAR models and 163 of the more powerful H-21B assault transport variant.[1] The H-21B was equipped with an uprated version of the Wright 103 engine, developing 1,425 shaft horsepower (1,063 kW) and featured rotor blades extended by 6 inches (152 mm). With its improved capabilities, the H-21B could carry 22 fully equipped infantrymen or 12 stretchers, plus space for two medical attendants, as a medevac helicopter. With its Arctic winter capabilities, the H-21A and H-21B were put into service by the USAF and the Royal Canadian Air Force (RCAF) to maintain and service Distant Early Warning Line (DEW) radar installations stretching from the Aleutian Islands and Alaska across the Canadian Arctic to Greenland and Iceland.

Piasecki H-21 cabin interior looking towards the cockpit

In 1952, some H-21As were evaluated by USMC helicopter squadron HMX-1 for air assault.[2] In 1957, an H-21B was loaned to the United States Marine Corps (USMC) to evaluate the helicopter as an airborne tug to tow disabled landing ships and amphibious landing vehicles to the beach. During the evaluation, the H-21B towed an LST at 5 kn (9.3 km/h; 5.8 mph) and a simulated tracked amphibious vehicle from the water to the beach.[3] The uprated 1425 hp Wright engine used in the H-21B was also used in subsequent variants sold to both the U.S. Army (as the H-21C Shawnee) and the military forces of several other nations. In 1962, the H-21 was renamed the CH-21 in U.S. Army service.

In 1959 Vertol Aircraft, the new name for Piasecki Helicopters, came up with a concept for heavy lift over short distances where between two and six H-21Bs would be linked by beams to lift heavy loads. It was considered to be unsafe, because if one helicopter had mechanical problems during the lift it could unbalance the structure and cause all helicopters to crash.[4]

Operational history

[edit]

French service in the Algerian War

[edit]
A Shawnee over rice paddies in Vietnam

In 1956, seeking a way to use helicopters for ground-attack in the Algerian War, the French Air Force and French Army Aviation (Aviation Légère de l'Armée de Terre) experimented with arming the Sikorsky S-55, then being superseded in service by the more capable Piasecki H-21 and Sikorsky H-34 helicopters. Some French Air Force and Army aviation H-21C helicopters were subsequently armed with fixed, forward-firing rockets and machine guns. A few even had racks for bombs but tests found that the H-21C lacked the maneuverability and performance needed for ground-attack. The H-21C was far more successful as a troop transport, and most H-21Cs in service were eventually fitted with flexible door-mounted guns such as the .50 cal. (12.7 mm) M2 Browning machine gun or the (ex-German) MG 151/20 20 mm aircraft autocannon, for defensive use when landing assault forces under fire.[5][6][7]

Though the H-21 had been removed from ground-attack, official U.S. Army evaluations at the time indicated that the type was actually more likely to survive hits by ground fire than was the Sikorsky CH-34; this was assumed to be a consequence of the location and construction of the CH-34's fuel tanks. By the close of the Algerian War, troop-carrying H-21C helicopters were being used in concert with H-34 ground-attack helicopters in large counterinsurgency operations.[5][6][7]

U.S. Army operations

[edit]

The H-21C saw extensive service with the U.S. Army, primarily for use in transporting troops and supplies. On 24 August 1954, with the assistance of inflight refueling provided by a U.S. Army U-1A Otter, a H-21C known as Amblin' Annie became the first helicopter to cross the United States non-stop.[8][9] Experiments were made by the Army in arming the H-21C as a gunship; some Shawnees were armed with flex guns under the nose, while others were fitted with door guns.

H-21 Shawnees of the 8th Transportation Company, Ft Bragg, 1956. The company had 24 helicopters, 48 officers and warrant officers, and 246 enlisted men.

One experimental version was tested with a Boeing B-29 Superfortress .50 cal. remote turret mounted beneath the nose. The H-21C (later designated CH-21C) was first deployed to South Vietnam in December 1961 with the Army's 8th and 57th Transportation Companies, in support of Army of the Republic of Vietnam troops. In Army service, the CH-21C Shawnee could be armed with 7.62 mm (.308 in) or 12.7 mm (.50 in) flexible door guns. Relatively slow, the CH-21's unprotected control cables and fuel lines proved vulnerable to the Vietcong, which were increasingly well supplied with automatic small arms and heavy (12.7 mm) anti-aircraft machine guns.

The H-21, which was designed for cold weather operations, performed poorly in the hot weather of Vietnam. Despite being capable of carrying 20 passengers, it could lift only nine when operating in Vietnam. Pilots reported that engines that were rated for 600 hours of flying time were lasting only 200 hours or less in Vietnam.[10] The shooting down of a CH-21 Shawnee near the Laotian-Vietnamese border with the death of four aviators in July 1962 were some of the U.S. Army's earliest casualties in the Vietnam War.[11] Despite these events, the Shawnee continued in service as the U.S. Army's helicopter workhorse in Vietnam until 1964 when it was replaced with the Bell UH-1 Huey. In 1965, the Boeing CH-47 Chinook was deployed to Vietnam and later that year, most CH-21 helicopters were withdrawn from active inventory in the U.S. Army and Air Force.

Variants

[edit]
XH-21
USAF designation of the first H-21 prototype.
YH-21 Work Horse
USAF Search And Rescue (SAR) version of the HRP-2 for service test, eighteen built
H-21A Work Horse (Model 42)
Same as YH-21 with detailed changes and powered by one 1250hp Wright R-1820-102, re-designated CH-21A in 1962, 32 built for USAF, 6 for the Royal Canadian Air Force
H-21B Work Horse (Model 42)
Same as H-21A but with uprated Wright engine (1425hp) and seats for 20 troops, autopilot as standard and limited armour protection and external fuel tanks, became CH-21B in 1962, 163 built for U.S. forces. 10 built for Japanese Self-Defense Forces; 10 H-21B built for the French Navy.
SH-21B Work Horse
Rescue conversion of the H-21B, became HH-21B in 1962.
H-21C Shawnee (Model 43)
US Army version of the H-21B, became CH-21C in 1962, 334 built for U.S. forces. 32 built under license by Weser Flugzeugbau for the West German Army. 98 built for the French Air Force and French Army Aviation (ALAT).
XH-21D Shawnee (Model 71).
Two H-21Cs re-engined with two General Electric T58 turboshaft engines in place of the Wright R-1820. Not placed into production.
CH-21A
H-21A redesignated in 1962.
CH-21B
H-21B redesignated in 1962.
CH-21C
H-21C redesignated in 1962.
HH-21B
SH-21B redesignated in 1962.
Model 42A
Conversion by Vertol Aircraft (Canada) of eight Royal Canadian Air Force H-21s for civilian use. Equipped to carry 19 passengers or 2,820lb (1,279kg) of internal cargo or a 5,000lb (2,268kg) slung load.
Model 44A
Commercial 19-passenger transport version of the H-21B. 11 total (Swedish military designation: Hkp 1), 2 for the Swedish Air Force, 9 for the Swedish Navy. 2 used for test/evaluation purposes by Japan Self-Defense Forces.
Model 44B
Commercial 15-passenger/freighter version of the H-21B.
Model 44C
Commercial eight-passenger executive version of the H-21B.
CH-127
Vertol Canada Model 44
Piasecki HkP1
Piasecki model 44 for the Swedish Navy

Operators

[edit]
A US Army H-21 in flight

Military operators

[edit]
 Canada
 Democratic Republic of the Congo
 France
Hkp 1 in Swedish Navy markings
 Japan
 Sweden
 United States
An HH-21 with US Air Force
 West Germany

Civil operators

[edit]
 United States

Aircraft on display

[edit]

Canada

[edit]

France

[edit]
A USAF CH-21B at the National Museum of the United States Air Force
  • FR94 – H-21C on static display at the Musée de l'Aviation Légere de l'Armée de Terre et de l'Hélicoptère in Dax, Landes.[25]
  • FR106 is on display at the "Ailes Anciennes" Museum at Toulouse-Blagnac Airport.[26]

Germany

[edit]

Japan

[edit]

Russia

[edit]

Sweden

[edit]

United States

[edit]
Airworthy
Static Display
Model 44A with the JGSDF at Bihoro Aviation Park, August 2009
CH-21 in RCAF markings at the Canadian Museum of Flight
Stored or under restoration

Specifications (CH-21C)

[edit]
3-view line drawing of the Piasecki YH-21 Workhorse
3-view line drawing of the Piasecki YH-21 Workhorse

Data from U.S. Army Aircraft Since 1947[78]

General characteristics

  • Crew: 3–5 (Pilot, co-pilot, crew chief and one or two gunners in Vietnam)
  • Capacity: ** 20 troops or
    • 12 stretchers
  • Length: 52 ft 6 in (16.00 m)
  • Height: 15 ft 9 in (4.80 m)
  • Empty weight: 8,950 lb (4,060 kg)
  • Gross weight: 15,200 lb (6,895 kg)
  • Powerplant: 1 × Wright R-1820-103 Cyclone 9-cylinder air-cooled radial piston engine, 1,425 hp (1,063 kW)
  • Main rotor diameter: 2 × 44 ft 0 in (13.41 m)
  • Main rotor area: 3,041 sq ft (282.5 m2) * Blade section: – NACA 0012[79]

Performance

  • Maximum speed: 127 mph (204 km/h, 110 kn)
  • Cruise speed: 98 mph (158 km/h, 85 kn)
  • Range: 265 mi (426 km, 230 nmi)
  • Service ceiling: 9,450 ft (2,880 m)
  • Disk loading: 5 lb/sq ft (24 kg/m2)
  • Power/mass: 0.09 hp/lb (0.15 kW/kg)

Armament

See also

[edit]

Related development

Aircraft of comparable role, configuration, and era

Related lists

References

[edit]
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[edit]
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