Sikorsky Aircraft Corporation’s two-seat S-52, the first helicopter to have all-metal rotor blades, first flew on 12 February 1947. Sikorsky developed a four-seat model and gave it the more powerful Franklin 0-425-1 engine. This model was first accepted first by the Marine Corps. It received the designation HO5S-1.
The Coast Guard acquired their HO5S-1Gs in September 1952. They proved to be weight limited. Short ranged and the cabin space was too small.