Igor Sikorsky’s background as pioneer Russian aviator, designer and World War One flyer, seemed to be just a preparation for his conquest of rotary wing flight. Although acknowledged as the creator of the first multi-engined airliner, the S-23 Ilya Muromets (a development of his ill-fated S-22 Le Grand), the outbreak of WW1 prevented the fame and fortune which would have followed from this design.
Sikorsky had been experimenting in Russia, as far back as 1909, with his first helicopter design but he soon realized that the primitive internal combustion engines of the day would be far too heavy to give the required power to weight ratio for vertical take-off and landing, and abandoned this first attempt. Following the Russian Civil War, Igor Ivanovich Sikorsky emigrated to the USA, as the chaotic situation in Bolshevik Russia in 1919 did not seem to promise him any kind of creative freedom.
Sikorsky Manufacturing Co. Inc., the company that Igor Sikorsky had formed, became Vought-Sikorsky, a part of United Aircraft in Connecticut and, during the 1930s, produced large aircraft such as the S.42, a transAtlantic, 4-engined flying boat. However, Sikorsky was still obsessed with solving the ‘helicopter problem’. There were many others in the field, the Spaniard Juan de la Cierva for example, but Sikorsky seemed to solve the practical problems (anti-torque tail rotor, cyclic pitch control, etc) and gain the all-important military contracts in the later days of WW2.
By 13th May, 1940, his Vought-Sikorsky VS-300 had made its first ‘free’ flight, and this was rapidly developed into the VS-316. Here we see an R-4B of the U S Army (43-46503), at the New England Air Museum, which was a production version of the VS-317; both the Army and the US Navy were eager to obtain practical helicopters for medevac, logistic support, search and rescue and, in the case of the Navy, ‘plane guard’ duties stationed alongside aircraft carriers during ‘launch/recovery’ operations. R-4′s were used towards the end of WW2, particularly in the China-Burma-India theater, where jungle terrain made ‘vertical rescue’ the only safe option for many sick soldiers or downed aircrew. Powered by a Warner Super Scarab R-550-3 of only 200hp, the aircraft had a limit of just 400lb for the two crew!
Despite these limitations, the Royal Air Force was equally eager to obtain the R-4, particularly since Juan de la Cierva (who the British authorities had asked to develop a helicopter) had been killed in the crash of a KLM DC-2 near Croydon Airport, in December, 1936. The RAF and Royal Navy called the R-4 the Hoverfly 1, and formed a Helicopter Training Flight as part of No. 43 Operational Training Unit, at RAF Andover. Using nine Hoverfly 1, Army Air Corps pilots were given a 5 week conversion course, as well as RAF and RN personnel. Ironically, some of these helicopters were detached to the King’s Flight, RAF in from August to September 1947 to fly mail between the Royal Castle of Balmoral in the Scottish Highlands and Aberdeen (Dyce) Airport, when the Royal family were in residence – they landed on the cricket pitch at Balmoral! One of the pilots who performed this new duty was none other than Brian Trubshaw, later to become Chief Test Pilot of the British Aircraft Corporation, and the person who was in command of the first flight of the British-built Concorde prototype, No. 002! The RAF Museum also has a preserved R-4B (painted as a Hoverfly, of course).
Sikorsky helicopters are still being built, and it is safe to say that Igor Ivanovich Sikorsky deserves his reputation as a giant in the field of aeronautical engineering.