The Bell HSL (Model 61) was an American 1950s

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are t ...

(ASW) helicopter built by the

Bell Helicopter Bell Textron Inc. is an American aerospace manufacturer headquartered in Fort Worth, Texas. A subsidiary of Textron, Bell manufactures military rotorcraft at facilities in Fort Worth, and Amarillo, Texas, as well as commercial helicopters in M ...

company, the only

tandem rotor Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two ...

type designed by Bell.

Design and development

The prototype Bell Model 61 first flew on 3 March 1953; it had been designed to meet a

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

requirement for an anti-submarine warfare helicopter. In June

1950 Events January * January 1 – The International Police Association (IPA) – the largest police organization in the world – is formed. * January 5 – 1950 Sverdlovsk plane crash, Sverdlovsk plane crash: ''Aeroflot'' Lisunov Li-2 cr ...

, the Model 61 was announced as the winner of the competition, and three XHSL-1 evaluation aircraft were ordered. The Model 61 had a rectangular-section fuselage structure and four-leg, six-wheel landing gear. It was powered by a

Pratt & Whitney R-2800 The Pratt & Whitney R-2800 Double Wasp is an American twin-row, 18-cylinder, air-cooled radial aircraft engine with a displacement of , and is part of the long-lived Wasp family of engines. The R-2800 saw widespread use in many importan ...

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

mounted in the aft fuselage. Crew included two pilots and two sonar operators. Because of the urgency of the requirement, low-rate production was ordered almost immediately after Bell received a contract for three XHSL-1s. The Navy eventually contracted for at least 160 production aircraft, including 18 intended for the

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

. Bureau Numbers were assigned for a total of 234. Because of development problems that resulted in poor schedule performance to the contract, only 50 were built. Although all were delivered, after service test and acceptance only a handful were used, for the development of airborne mine sweeping. The rest were delivered directly into storage and were subsequently struck off.

Operational history

The HSLs were not used operationally. Approximately seven were assigned to the U.S. Naval Air Mine Defense Unit at Panama City, Florida, for the development of airborne mine-sweeping, the first arriving in September 1956 and the last being struck off in early 1960.

Variants

;XHSL-1 :two experimental flight test and one static test article ;HSL-1 :production version, 50 built. ;Bell Model 61 :Company designation for the HSL ;Bell D-116 : A proposed civil variant of the Model 61, not proceeded with. ;Bell D-216 : A proposed variant of the HSL, not proceeded with. ;Bell D-238 : A proposed variant of the HSL, not proceeded with.

Operators

; *

Specifications (HSL-1)

References

;Notes ;Bibliography * Andrade, John M. ''U.S.Military Aircraft Designation and Serials since 1909''. Leicester, UK: Midland Counties Publications, 1979. . * ''The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985)''. London, Orbis Publishing, 1985. * Thomason, Tommy H. ''The Forgotten Bell HSL''. Simi Valley, CA: Ginter Books, 2005.

External links

helis.com: Helicopter history site
{{USN helicopters 1950s United States anti-submarine aircraft Tandem rotor helicopters 1950s United States helicopters Single-engined piston helicopters Aircraft first flown in 1953 HSL