Piasecki H-21

Piasecki H-21 Workhorse
H-21B "Workhorse" of the US Air Force
Type:	Transport helicopter
Design country:	United States
Manufacturer:	Piasecki Helicopter Corporation
First flight:	April 11, 1952
Production time:	1954 to 1959
Number of pieces:	714

Swedish H-21

Cockpit of an H-21

H-21C of the Army

Air Force H-21C

The Piasecki H-21 Workhorse (factory designation: PD-22 ) was a transport helicopter made in the USA . It had two main rotors in tandem configuration and could carry up to 20 fully equipped soldiers with a two-man crew. The H-21 was u. a. used in the Vietnam War. The civil version offered from 1958 was called the Vertol 44 (later Boeing-Vertol 44).

history

The development of the H-21 goes back to the Piasecki model PV-3 , better known under the US Navy name HRP-1 Rescuer ( first flight in March 1945). In 1949 the derived version PV-17 ( HRP-2 Rescuer ) followed, which had a completely new fuselage made of all-metal, while the engine (440 kW (600 PS) Pratt & Whitney R-1340 ) was taken over unchanged.

On April 11, 1952, the H-21 (factory designation PD-22), derived from the HRP-2 , flew for the first time. With its 845 kW radial engine , it had almost twice as high an engine power as the HRP-1 . Series production began in 1954 with the H-21A , referred to by Piasecki as the workhorse ("workhorse"). Until the end of production in 1959, a B and a C version were produced, which were equipped with more powerful engines. In the US armed forces , the H-21 was given the nickname Shawnee , which, as usual, was borrowed from an Indian tribal designation.

When the Piasecki Helicopter Corporation was renamed Vertol Aircraft Corporation in May 1956, the internal name of this helicopter changed from PD-22 to Model V-43 . The designation reform the US armed forces then brought Type CH-21 ( C argo H elicopter, engl. For transport helicopters) with itself. From the US soldiers he was nicknamed flying banana ("flying banana"; due to the curved shape of the trunk) or army mule ("army mule", based on Workhorse ).

Military operation

(Partial) armed force	version	number of pieces
US Air Force	H-21A, H-21B	214
US Army	H-21C	334
France	H-21C	108
Germany	H-21C	32
Sweden	H-21C	11
Japan	H-21C	10
Canada	H-21C	5
Zaire	H-21C	3

Production for USAF and US Army

As part of the Mutual Defense Aid Program (MDAP), the H-21 was also delivered to allied countries.

Acceptance of the Piasecki H-21 by the USAF and the US Army:

version	1952	1953	1954	1955	1956	1957	1958	1959	TOTAL
YH-21	3	15th							18th
H-21A		20th	12						32
H-21B			5	81	61	14th			161
H-21C Army			32	54	90	134	22nd	2	334
H-21A MDAP			6th						6th
H-21 MDAP							6th		6th
TOTAL	3	35	55	135	151	148	28	2	557

Technical specifications

Sikorsky H-37 harbors a crashed Piasecki H-21

H-21C of the Army Aviation of the German Armed Forces in the Helicopter Museum Bückeburg

Parameter	Data
crew	2
Passengers	20 soldiers
Rotor diameter	13.50 m
Hull length	16.00 m
Length over all	26.20 m
height	4.70 m
Preparation mass	3,990 kg
Takeoff mass	6,950 kg
Cruising speed	158 km / h
Top speed	210 km / h
Hover altitude with ground effect	1,860 m
Service ceiling	2,880 m
Range	450 km
Engine	1 Wright R-1820-103 - radial engine with 1,048 kW (1,425 hp)

See also

• List of helicopter types

Web links

Commons : Piasecki H-21  - album with pictures, videos and audio files

Individual evidence

1. ^ Zaire, World Air Forces - Historical Listings ( Memento from January 25, 2012 in the Internet Archive )
2. ↑ The Aviation Forum 2 photos of Congolese H-21s
3. ↑ Statistical Digest of the USAF 1952 , p. 158; 1953, p. 185 f .; 1954, pp. 70 f .; 1955, p. 80 f .; 1956, p. 91 f .; 1957, p. 97 f .; 1958, p. 72; 1959, p. 68