The helicopter had two main rotors at either end of the fuselage tube, linked by a transmission but powered by a single Pratt & Whitney R-2800-50m, which was an 18-cylinder air-cooled radial engine.

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.

[1] Because of the urgency of the requirement, low-rate production was ordered almost immediately after Bell received a contract for three XHSL-1s.

Although all were delivered, after service test and acceptance only a handful were used, for the development of airborne mine sweeping.

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.