R-6 Hoverfly II Sikorsky Helicopter
The Sikorsky-designed R-6A two-seat observation helicopter was a refined version of the Sikorsky R-4, the first U.S. Air Corps helicopter to serve in a combat zone (May 1944). The R-6A, first flown in October 1943, used the same rotor and transmission system as the R-4, but had a more powerful engine. The fuselage was completely redesigned to reduce air resistance and provide improved pilot visibility. As a result, the R-6A bore little resemblance to its boxy-looking R-4 predecessor.
Sikorsky built the first six of the helicopters (one XR-6 and five XR-6As), but another 219 R-6As were produced in 1944 and 1945 by Nash-Kelvinator under license from Sikorsky. The production version was designated as the R-6A.
Although primarily an observation and liaison helicopter, many R-6As also were equipped with capsules on each side of the fuselage to carry litters for medical evacuation. Bomb racks also could be installed and the R-6A could be equipped with floats for operation from water.
The Navy procured three of the experimental models, designated XR-6A, from the Army Air Force's acquisitions in late-1943 and were given the Navy designation of XHOS-1. One was sent to Floyd Bennett Field for evaluation by the Coast Guard. The Navy then acquired 36 R-6As (which were redesignated as HOS-1s) from the Army Air Force and the Coast Guard purchased 27 of these between January 1945 and January 1946. Of these, two were destroyed in crashes (no fatalities), and the rest were returned to the Navy by May 1949.
R-6 Sikorsky Specifications and Performance
||10 ft. 5 in.
||3,243 lbs. loaded
||235 hp Franklin 0-405-9
U.S. Army Air Force R-6A parked on a road in China, 1945.
A Coast Guard HOS-1 (Sikorsky R-6A) at San Francisco in the late 1940s. A retriever boom and pulley has been installed to assist with rescue.
Sikorsky R-6A at the National Museum of the United States Air Force.