The Bell 47 is a two-bladed, single engine, light helicopter manufactured by Bell Helicopter. Based on the third Model 30 prototype, Bell’s first helicopter designed by Arthur M. Young, the Bell 47 became the first helicopter certified for civilian use on 8 March 1946. More than 5,600 Bell 47 aircraft were produced, including those produced under license by Agusta in Italy, Kawasaki Heavy Industries in Japan, and Westland Aircraft in the United Kingdom. The Bell 47J Ranger is a modified version with a fully enclosed cabin and fuselage.
In 1947, the United States Army Air Forces (later the 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 U.S. Navy version of the 47 was designated the HTL-4, and dispenses with the fabric covering on the tail boom. The U.S. 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-1Gin 1959.
The H-13 was used as observation helicopter early in the Vietnam War, before being replaced by the OH-6 Cayuse.
The Bell 47 was ordered by the British Army as the Sioux to meet specification H.240, with licensed production by Westland Helicopters. In order to comply with the terms of its licence agreement with Sikorsky Aircraft, which prevented it building a U.S. competitors aircraft, Westland licenced the Model 47 from Agusta, who had purchased a license from Bell. The first contract was for 200 helicopters. The first 50 helicopters of the contract were built by Agusta at Gallarate in Italy followed by 150 built by Westland at Yeovil. The first Westland Sioux made its maiden flight on 9th March 1965.
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