H.Nowarra, G.Duval Russian Civil and Military Aircraft 1884-1969

Two years later, and no doubt inspired by the first helicopter flight made in 1909 by Paul Cornu in France, Sikorski tried again with his S.2 helicopter, using the same 25 h.p. engine, but this time driving three-blade rotors. The machine weighed about 400 lb., and only developed lift equal to its weight. Therefore, although capable of hovering flight, it could not carry a pilot. Sikorski now turned to the design of fixed-wing aircraft.

A.Durkota, T.Darcey, V.Kulikov The Imperial Russian Air Service (Flying Machines)

Igor Ivanovich Sikorsky

Helicopter No.2

  In February 1910, Sikorsky began construction of helicopter No.2 (H-2). The H-2 had two three-bladed rotors that were situated on top of a small fuselage cage made of steel tube and wire braced. The blades were constructed with spars and ribs and were wire braced to the shaft. Power was provided by a 25hp Anzani engine. Like the first machine, this helicopter seems to have had collective pitch control only; no provision had been made for horizontal flight controls.
  Testing took place during April and early May of 1910. About mid-May Sikorsky concluded that the 400-pound machine was incapable of flying with a person on board. As a result, Sikorsky "temporarily postponed" further helicopter research as his first fixed-wing design, the S-1, was rapidly nearing completion. The H-2 was exhibited at the First Kiev aeronautics show in June of 1910, and disassembled soon afterwards.