World Library  
Flag as Inappropriate
Email this Article

Sikorsky R-6

Article Id: WHEBN0026686909
Reproduction Date:

Title: Sikorsky R-6  
Author: World Heritage Encyclopedia
Language: English
Subject: Sikorsky S-61R, Sikorsky S-52, Sikorsky SH-60 Seahawk, Sikorsky UH-60 Black Hawk, List of United States military helicopters
Publisher: World Heritage Encyclopedia

Sikorsky R-6

R-6, Hoverfly II
R-6A Hoverfly II at the USAF Museum
Role Helicopter
National origin United States
Manufacturer Sikorsky Aircraft
Designer Igor Sikorsky
First flight 15 October 1943
Introduction 1945
Status Several preserved in museums
Primary users United States Navy
Royal Air Force
Number built 225
Developed from Sikorsky R-4

The Sikorsky R-6 was an American-built light two-seat helicopter of the 1940s. In Royal Air Force and Royal Navy service, it was named the Hoverfly II.


The R-6 Hoverfly II was developed to improve on the successful Sikorsky R-4. In order to enhance performance a completely new streamlined fuselage was designed and the boom carrying the tail rotor was lengthened and straightened. The main rotor and transmission system of the R-4 was retained.[1] Sikorsky allotted their Model 49 designation to the new design. Later, dynamically balanced modifications to the rotor were carried out by Doman Helicopters Inc. The new aircraft could attain 100 mph compared with 82 mph by the earlier design.

Initial production was by Sikorsky, but most examples were built by Nash-Kelvinator. Some of the later aircraft were fitted with more powerful engines.

Operational history

The first R-6s were delivered to the United States Army Air Forces (USAAF) in late 1944 and some were transferred to the United States Navy (USN). It was initially intended to pass 150 R-6s to the Royal Air Force (RAF), but delays caused by the switch of production from Sikorsky's factory at Stratford, Connecticut to Nash-Kelvinator at Detroit Michigan meant that only 27 R-6As were actually delivered to the RAF as the Hoverfly II.[2] 15 of these were passed on to the Royal Navy's Fleet Air Arm (FAA).[3]

Some of the RAF examples were allotted to 657 Squadron RAF for proving the use of helicopters in the Army Co-operation role, and two external stretchers could be fitted to the fuselage. 657 Squadron operated their Hoverfly IIs as Air Observation Posts, spotting for Army artillery units. The Hoverfly IIs remained in operation until April 1951, and one squadron example was displayed at the September 1950 Farnborough Air Show.[4]

The FAA used their Hoverfly IIs in the training and liaison roles. Naval units to use the type included 771 Squadron from December 1945, followed by 705 Squadron.

The USAAF operated their R-6s in secondary roles and the survivors were redesignated H-6A in 1948. The USN examples were designated the HOS-1 and a further 64 were intended to be transferred from the USAAF, but this did not take place.

Disposals of surplus military Model 49s were made in the civil market in the late 1940s but none now remain in operation. Four are currently displayed in US museums.[5]


R-6A Hoverfly II at USAF Museum
The R-6 was the basis for the Doman LZ-1A, which used the fuselage of a R-6A Hoverfly II. This example exhibited at the New England Air Museum at Windsor Locks, Connecticut in 2005
prototype powered by a 225 h.p. Franklin O-435-7 (1)
as XR-6 but powered by the 240 h.p. O-405-9 (5) of which 3 to the US Navy as XHOS-1
as XR-6A with small changes (26) built by Nash-Kelvinator
production model (193) built by Nash-Kelvinator of which 36 to US Navy as HOS-1 and 27 to the RAF as Hoverfly II
projected variant with 225 h.p. O-435-7, but not proceeded with
projected development of the XR-6 with a 240hp O-405-9 engine, not built.
Doman LZ-1A
One R-6A modified as a test bed with a Doman-designed hingless rotor blades and self-lubricating rotor hub.

R-6A aircraft on display

(data from Ogden, 2007)

Specifications (R-6A)

Data from Thetford, 1977

General characteristics
  • Crew: 1
  • Capacity: 1 observer
  • Length: 47 ft 11 in (14.61 m)
  • Gross weight: 2,600 lb (1,179 kg)
  • Powerplant: 1 × Franklin 0-405-9 piston, 240 hp (180 kW)
  • Main rotor diameter: 38 ft 0 in (11.58 m)


  • Maximum speed: 100 mph (161 km/h; 87 kn)
  • Service ceiling: 10,000 ft (3,048 m)


  1. ^ Swanborough, 1963, p.529
  2. ^ Butler, 2004, p.278
  3. ^ Thetford, 1977, p.422
  4. ^ Thetford, 1976, p.603
  5. ^ Ogden, 2007, p.602
  6. ^ "Sikorsky R-6 Doman Conversion (LZ-1A)


External links

Data and image of R-6

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.