It features a substantially revised fuselage with a rear loading ramp, a conventional, though watertight, hull instead of the S-61's boat-hull, and retractable tricycle landing gear.

Problems were encountered with its stability and the main transmission was limited to 2,000 horsepower, even though at peak power the engines could produce more.

[3]: 50 Notwithstanding the loss of the HRX competition, Sikorsky built an S-61R prototype as a private venture, with its first flight in 1963.

[6] In 1965, the U.S. Coast Guard ordered a version designated HH-3F Sea King (more commonly known by its nickname "Pelican") for all-weather air-sea rescue.

[4] The Pelican featured search radar with a nose antenna radome offset to port,[1][6] and water landing capability.

Between 31 May and 1 June 1967, two HH-3Es of the United States Air Force made the first nonstop flight across the Atlantic Ocean by helicopter.

Departing from New York in the early hours, the two helicopters arrived at the 1967 Paris Air Show at Le Bourget after a 30 hr 46 min flight.

[8] Agusta began production in 1974 and delivered 22 helicopters as replacements for the Grumman HU-16 Albatross used for SAR (Search and Rescue) missions at sea.

15º Stormo was also engaged with SAR missions in the hostile zones of the several operations abroad where Italian Armed Forces were deployed - Somalia, Albania, Bosnia, Kosovo, Iraq and Afghanistan.