S-52

The Sikorsky S‑52, also known as the HO5S, was a light, single‑engine helicopter developed by Sikorsky Aircraft Corporation in the late 1940s. First flown on 17 March 1947, the prototype demonstrated a novel three‑bladed main rotor and a fully articulated hub, which gave the machine superior stability and low‑vibration performance compared to earlier two‑bladed designs. Powered by a 275‑horsepower Warner R-550-1 radial engine, the S‑52 could reach a maximum speed of 115 mph, a service ceiling of 13 500 feet and a useful load of about 2 000 pounds, making it suitable for liaison, rescue and utility missions. Over 250 units were produced for the United States Navy, Army, Coast Guard and several foreign services, where the aircraft earned a reputation for reliable operation in harsh maritime and jungle environments. Its distinctive bubble canopy offered excellent visibility, a feature that later influenced the design of the iconic H‑19 Chickasaw. The S‑52’s successful integration of advanced rotor technology and compact powerplant paved the way for subsequent Sikorsky helicopters, cementing its role as a transitional platform that bridged early experimental rotors and the modern utility helicopters of the 1950s.

Sikorsky Aircraft Corporation

Classification

Design & Classification