H-21 Shawnee

H-21 Shawnee
Name	H-21 Shawnee
Caption	A United States Air Force H-21B
Type	Cargo/Utility helicopter
Manufacturer	Piasecki Helicopter
Designer	Frank Piasecki
First flight	11 April 1952
Introduction	1954
Retired	1967
Primary user	United States Air Force
More users	United States Army , French Air Force , Royal Canadian Air Force
Number built	707
Developed from	Piasecki HRP Rescuer
Variants with their own articles	Vertol 44

H-21 Shawnee. The Piasecki H-21 Shawnee was a tandem-rotor utility helicopter developed by Piasecki Helicopter for the United States Air Force and later adopted by the United States Army. Nicknamed the "Flying Banana" for its distinctive curved fuselage, it was designed for cold-weather operations and became a workhorse for transport and rescue missions. Its service spanned from the mid-1950s into the Vietnam War, where it saw extensive use before being phased out by more advanced turbine-powered designs.

Development

The H-21 originated from a United States Air Force requirement for a helicopter capable of operating in Arctic conditions, specifically to support the construction and maintenance of the Distant Early Warning Line. Building on the success of the earlier Piasecki HRP Rescuer, designer Frank Piasecki and his team at Piasecki Helicopter developed a larger, more powerful model. The company, which would later become Vertol and then part of Boeing Vertol, leveraged its expertise in tandem-rotor designs to create an aircraft with excellent lift capacity and stability. The first flight of the YH-21 prototype occurred on 11 April 1952, leading to a production contract from the United States Air Force.

Design

The H-21 featured a characteristic bent fuselage that accommodated its twin three-bladed tandem rotors, which were powered by a single Wright R-1820 Cyclone radial engine mounted in the rear fuselage. This configuration provided a large, unobstructed cabin space for up to 20 troops or 12 stretchers, accessible via clamshell rear doors. Its fixed tricycle landing gear and robust construction were suited for rough-field operations. For cold-weather performance, it incorporated a winterization kit and could be fitted with fixed skis or Edo floats for water landings. The design, while reliable, was criticized for being underpowered and vulnerable to ground fire due to its large frontal area and reliance on a single engine.

Operational history

Entering service with the United States Air Force in 1954 as the H-21A, the Shawnee initially performed search and rescue and Arctic support duties. The United States Army soon adopted an improved H-21B model for troop transport and medevac roles. During the early stages of the Vietnam War, the H-21 was among the first helicopters deployed by the United States Army and the Army of the Republic of Vietnam, conducting air assault and resupply missions under the operational umbrella of Military Assistance Command, Vietnam. It also saw significant service with allied nations, including the French Air Force during the Algerian War and the Royal Canadian Air Force. Its limitations in hot climates and combat zones led to its replacement by the Bell UH-1 Iroquois and Boeing CH-47 Chinook.

Variants

The primary variants were the H-21A, powered by a Wright R-1820-103 engine for the United States Air Force, and the more powerful H-21B for the United States Army, which used a Wright R-1820-103 engine. A commercial derivative, the Vertol 44, was marketed for civilian cargo and passenger transport. The United States Navy and United States Coast Guard operated a small number of similar helicopters designated as the HRB-1 and later CH-21C for utility duties. The Royal Canadian Air Force flew the CH-127, which was essentially an H-21B under a Canadian designation.

Operators

The primary military operator was the United States Air Force, followed closely by the United States Army. The French Air Force and French Navy used the H-21 extensively in Algeria and French Indochina. The Royal Canadian Air Force operated the type for northern transport and search and rescue. Other operators included the West German Army, the Royal Swedish Air Force, the Japan Ground Self-Defense Force, and the Burmese Air Force. Several were also used by civilian operators like New York Airways and Los Angeles Airways for scheduled passenger service.

Specifications (H-21B)

* **Crew:** 2 * **Capacity:** 20 troops or 12 stretchers * **Length:** 52 ft 6 in (16.0 m) * **Rotor diameter:** 44 ft 0 in (13.41 m) (each) * **Height:** 15 ft 9 in (4.80 m) * **Empty weight:** 8,950 lb (4,060 kg) * **Max takeoff weight:** 15,200 lb (6,895 kg) * **Powerplant:** 1 × Wright R-1820-103 Cyclone 9-cylinder air-cooled radial engine, 1,425 hp (1,063 kW) * **Maximum speed:** 127 mph (204 km/h, 110 kn) * **Range:** 265 mi (426 km, 230 nmi) * **Service ceiling:** 9,450 ft (2,880 m) * **Armament:** Typically unarmed, but could be fitted with door-mounted M1919 or M60 machine guns in Vietnam.

Category:Piasecki aircraft Category:United States military utility aircraft 1950–1959 Category:Tandem-rotor helicopters