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HSL (Bell Model 61)
Role tandem-rotor ASW helicopter
National origin United States
Manufacturer Bell Helicopter
First flight 3 March 1953
Introduction 1957
Primary user United States Navy
Number built 53 including one static test article

The Bell HSL (Model 61) was an American 1950s anti-submarine warfare (ASW) helicopter built by Bell Helicopter company, the only tandem rotor 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 requirement for an anti-submarine warfare helicopter. In June 1950, 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 a four-leg, six-wheel landing gear. It was powered by a Pratt & Whitney R-2800 radial engine mounted in the aft fuselage. Crew included two pilots and two sonar operators.[1]

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 Royal Navy. 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.


two experimental flight test and one static test article
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.


United States

Specifications (HSL-1)

Data from [2]

General characteristics

  • Crew: 4
  • Length: 39 ft 1 in (11.9 m) (fuselage only)
  • Width: 11 ft 6 in (3.5 m) (rotors folded)
  • Height: 14 ft 6 in (4.42 m)
  • Gross weight: 26,500 lb (12,020 kg)
  • Rotor diameter' (both) 51ft 6in (15.7m)
  • Rotor disc area 4,170sq ft (387.4sq m)
  • Powerplant: 1 × Pratt & Whitney R-2800-50 18-cyl. two-row air-cooled radial piston engine, 2,400 hp (1,800 kW)


  • Maximum speed: 115 mph (185 km/h; 100 kn)
  • Cruise speed: 96 mph (83 kn; 154 km/h)
  • Range: 350 mi (304 nmi; 563 km)

See also




  1. "Navy's Most Powerful Helicopter to Hunt Submarines." Popular Mechanics, August 1953, p. 121.
  2. Pelletier, Alain J. (1992). Bell Aircraft since 1935 (1st ed.). London: Putnam & Company Ltd.. pp. 100–102. ISBN 1-55750-056--8. OCLC 91-66350. 
  • Andrade, John M. U.S.Military Aircraft Designation and Serials since 1909. Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9.
  • 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. ISBN 978-0-942612-70-7

External links

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