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Sikorsky R-6

Ordered in 1943, the Sikorsky XR-6 prototype (43-47955) made its maiden flight on 15 October 1943. As its manufacturer's designation indicated, it was essentially a refined and developed version of the R-4, and the same rotor and transmission system was used in both types. A 225hp Lycoming O-435-7 engine provided the power, and the fuselage was transformed into a highly streamlined, metal-skinned unit with a one-piece moulded plexiglas cabin for the 2 crew members. On a March 1944 the XR-6 set new helicopter distance, endurance and altitude records when it made a non-stop flight of 623km from Washington, D.C, to Dayton, Ohio, in 4 hr. 55 min, climbing to 1524m over the Allegheny Mountains en route. The XR-6 was followed by five 2-seat service test XR-6A's for the USAAF and U.S. Navy, built by Sikorsky with 240hp Franklin O-405-9 engines, and twenty-six generally similar pre-production YR-6A's built by the Nash-Kelvinator Corporation. The latter company also carried out the production of the one hundred and ninety-three R-6A's built from 1945. Thirty-six of these were delivered to the U.S. Navy as the HOS-1, and formed the equipment of that service's first helicopter squadron, which commissioned in July 1946. Forty R-6A's were supplied to Britain under Lend-Lease, these being named Hoverfly II in British service. Fifteen of them were allocated to the Fleet Air Arm for communications and training in 1946; others served with No.657 (AOP) Squadron RAF and the Airborne Forces Experimental Establishment. Like the R-4, the R-6 could be fitted with pontoons as an alternative to a wheeled landing gear, and was employed on a variety of duties including air/sea rescue, casualty evacuation and observation. Its career was, however, a short one: it was frequently beset by engine difficulties, and soon gave way to the more reliable R-5 and its derivatives. A proposed Lycoming-powered R-6B version by Nash-Kelvinator was cancelled.

K.Munson "Helicopters And Other Rotorcraft Since 1907", 1968

Sikorsky R-6

The R-4's rotor and transmission system was installed in a new streamlined fuselage with an all-metal semi-monocoque tail boom to become the VS-316B or XR-6, powered by a 168kW Avco Lycoming O-435 engine. Some 193 production helicopters were built for the USAAF as the R-6A, for the US Navy as the HOS-1 and for the British as the Hoverfly Mk II.

D.Donald "The Complete Encyclopedia of World Aircraft", 1997

Photo Gallery 

The Sikorsky R-6 was developed parallel with the improved R-5 but was basically a refinement of the R-4 design. Note its four-wheel landing gear arrangement, streamlined structure and improved frontal visibility.

An R-6A assigned to SAR operations, with Rescue painted on the top of the tailboom and high-visibility markings. Beginning with the R-6, helicopters flown by the U.S. Coast Guard had Navy designations with the suffix letter G (as HOS-1G) until the 1962 redesignation of U.S. military aircraft.

Sikorsky R-6

Technical data for Sikorsky R-6

Crew: 1, passengers: 1, engine: 1 x Avco Lycoming O-435 rated at 168kW, rotor diameter: 11.6m, length: 11.7m, height: 3.2m, take-off weight: 1317kg, empty weight: 923kg, max speed: 161km/h, cruising speed: 120km/h, rate of climb: 4.0m/s, service ceiling: 3050m, range: 185km

Doug Schaeffer, e-mail, 30.01.2013reply

I head up the restoration team at the American Helicopter Museum in West Chester, Pa. We are currently restoring an R-6.....1 of 4 in the U.S. that we are aware of....1- Fort Rucker, Alabama, 2-Air Force Museum in Dayton, Ohio, 3-New England Air Museum and ours.
I just printed a set of the Comet Model Plans so we can add that to the mix.


KARL R. RENZ III, e-mail, 04.09.2020 Doug Schaeffer

Do you have a set of specs for the R6 as I have to move one and I need to know if it will fit on my trailer, thanks


Stan Berman, e-mail, 28.06.2011reply

I too have aquired the plans from the old "COMET" kit. I am in the process of building the model of the Sikorsk R-6.
As Jon Winder asked, does anyone have any good photos of this aircraft.

While I'm at, does anyone have any othe plans or kits of balsa wood models of other helicopters ?

Barrie R Burns, e-mail, 24.08.2011reply

I have aquired a copy of the old Comet drawing, through the kindness of Bill Parker of Texas USA. I am three parts through the build, will send photo. to any one interested when finished, thought it was good challenge for me to have ago at.

don, e-mail, 03.06.2010reply

This helicopter would have beat the Bell 47 to Korea but after the war they were stored in the open,The magnesium rotted and the helicopters were junk .When war broke out it was a big break for Bell.

Jon Winder, e-mail, 28.02.2010reply

I am going to build a model of this helicopter. I have the plans from an old "COMET" model kit but I wanted to find some pictures.

kiran, e-mail, 20.04.2009reply

will u send me model sketch of your project let me know something about your project please

kiran, e-mail, 20.04.2009reply

will u send me model sketch of your project let me know something about your project please

Keith Besherse, e-mail, 02.11.2007reply

What was the R6's manufacturer's designation? The R4 article lists it as the VS316A but this article doesn't tell us what Sikorsky called the design.

Erik H., e-mail, 14.06.2007reply

219 R-6A's were built by Nash-Kelvinator in 1944-45 under license from Sikorsky

Ed B., e-mail, 23.04.2007reply

I lived near Nash-Kelvinator during the production years of the helicopter. (Canadian Air Attache rented space in my home.) Was wondering if any of the R-4s were built by

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