Sikorsky HO5S-1/HO5S-1G
Historical Information:
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. According to Pearcy, however, their performance was less than expected. "With a top speed of 90 knots, its small size, short range, and low life capability limited its effectiveness with the Coast Guard." The surviving helicopters were placed in storage beginning in April of 1954 and were eventually transferred to the U.S. Army with one example, CG-1251, being transferred to the U.S. Air Force Museum at Wright Patterson AFB. Two others were transferred to CAA Technical Development & Evaluation Center in Indianapolis.
No caption/date; Photo No. 80-G-197440; National Archives photo.
Coast Guard HO5S-1, #1244, during a test flight at the Sikorsky factory in Connecticut, prior to delivery to the Coast Guard during September 1952.
No caption/date/photo number; photographer unknown.
U.S. Army Field Forces HO5S-1.
Sources:
Arthur Pearcy, U.S. Coast Guard Aircraft Since 1916 (Annapolis: Naval Institute Press, 1991), pp. 292-293.
HO5S A/C Historical File, Coast Guard Historian's Office.