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-9 Sikorsky S-9 The Sikorsky S-9 "Kruglyj" (Rounded One) was a Russian single engine prototype aircraft completed in the spring of 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-9 was a three-seat mid-wing monoplane with constant-chord wire-braced wings originally powered by a Gnome air-cooled rotary engine rated at . It was the first monocoque monoplane built in Russia and the cylindrical tapered fuselage was constructed of plywood 5 mm thick in the forward section and 3mm thick aft. Construction was completed in the spring of 1913. Upon