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-42 span the oceans. The new design would need increased lifting capacity to carry enough fuel and 300 pounds of mail, but no passengers, for a 2,500 miles (4,023 kilometers) nonstop flight against a 30 mph (48 km/h) wind, at a higher cruising speed than the norm for similar flying boats at that time. Of the six companies tenders had been sent to, only Sikorsky and Martin provided submissions. Sikorsky offered the S-42. The other offer was the more ambitious Martin M-130. The new Sikorsky design, the S-42, had major aerodynamic improvements over the S-40. Igor Sikorsky said, "in its very