Bell HTL-6
United States — three-seat general utility helicopter

Archive Photos

1955 Bell HTL-6 (Model 47G, RCN 1387, c/n 1387) c.2003 at the Canada Aviation Museum, Ottawa, Ontario, Canada


The H-13 Sioux was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT.2.


In 1947, the United States Army Air Forces (later United States Air Force) ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name "Sioux".

Initially, the United States Navy procured several Bell 47s, designated HTL-1, between 1947 and 1958. The United States Coast Guard evaluated this model, and procured two HTL-1s for multi-mission support in the New York Harbor. The most common US Navy version of the 47 was designated the HTL-4, and dispenses with the fabric covering on the tail boom. The US Coast Guard procured three HTL-5s in 1952 (similar to the HTL-4 but powered by a Franklin O-335-5 engine) and used these until 1960. The Coast Guard procured two of Bell’s Model 47G and designated them HUL-1G in 1959.

The H-13 was used as observation helicopter early in the Vietnam War, before being replaced by the OH-6 Cayuse.

The Sioux was ordered by the British Army to meet specification H.240, the first contract was for 200 helicopters. The first 50 helicopters of the contract were built by Agusta at Gallerate in Italy followed by 150 built by Westland Aircraft at Yeovil. The first Westland Sioux made its first flight on 9 March 1965.


The Sioux is a three seat observation and basic training helicopter. The Bell 47G design was introduced in 1953. This design can be recognized by the full bubble canopy, exposed welded-tube tail boom, saddle fuel tanks, and skid landing gear.

The H-13 and its military variants were often equipped with medical evacuation panniers, one to each skid, with an acrylic glass shield to protect the patient from wind.

A single 260 hp Lycoming VO-435 piston engine was fitted to the 47G variant. The fuel were fed from two high level mounted external tanks. A two bladed single rotor with short inertial stabilizing minor blades was used on the Sioux.


Civil Variants

Military Variants

Licensed Versions



Specifications (Sioux AH.1)

General Characteristics



Specifications (Model 47D-1 / OH-13E) 3

General Characteristics


Weights and Loadings


Popular Culture

The Bell 47 appeared, and played key roles, in film and television productions. It has been associated with both the M*A*S*H film, and the M*A*S*H television series, and the Whirlybirds TV series (1957-1959).


  1. In the military of the United States, the Bell 47 carried several designations prior to 1962.
  2. R-13 was the first designation by the United States Army Air Forces, while the Navy designated their training version as HTL.
  3. In 1948, the United States Air Force changed the designation to H-13 which was also adopted by the Army, adding the name Sioux.
  4. The Navy and Coast Guard designated utility models as HUL.
  5. In 1962, under a joint designation system created by the Department of Defense, the designations for all of the helicopters were changed to a mission symbol followed by the vehicle type designator creating a two-letter prefix (OH, UH, XH, etc.), but the Bell 47 retained its original series number, 13 and the Army’s popular name.
  6. To denote different models, a letter suffix was appended to the designation.


  1. Shupek, John. Photos via The Skytamer Archive, copyright © 2009 Skytamer Images. All Rights Reserved
  2. Wikipedia, the free encyclopedia. H-13 Sioux
  3. Bridgman, Leonard, "Bell: The Bell Model 47 Helicopter." Jane’s All The World’s Aircraft 1950-51. Sampson Low Marston & Company Limited, London, 1950. pp. 202c


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