Sikorsky S-60 The helicopter accumulated 333 hours of flight in its two-year flight career, and was evaluated by the US Navy, with demonstrations also flown for the US Army. While effective in its designed role, the helicopter proved to be underpowered. Sikorsky was already working on an enlarged, turboshaft-powered successor, the Model S-64, which was ordered into production for the US Army as the Sikorsky CH-54 Tarhe. Igor Sikorsky was fully involved in the development of the prototype S-60, from the initial design through flight testing. It was one of the last aircraft to have this distinction. The prototype crashed in April
Sikorsky S-11 Sikorsky S-11 The Sikorsky S-11 " Polukroogly " (Half Round) was a Russian single engine prototype reconnaissance aircraft completed in July 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-11 was a two seat mid-wing monoplane with wire-braced wings powered by a Gnome Monosoupape air-cooled rotary engine rated at . It was smaller and lighter than the S-7 on which it was based, and had a conventional wooden fuselage. The cockpit featured side-by-side seating with controls for the pilot only on the left. Originally built with ailerons