Sikorsky had pursued helicopters since the company's founding in 1923, yet the S-55 did not fly until 1949. During those 26 years, carrier aviation went through about six aircraft generations in Royal Navy, US Navy, and Imperial Japanese Navy service. Rotary-wing engineering took much longer to reach practical reliability during an otherwise rapid period of aviation development. The result could carry useful troop or anti-submarine loads, a decisive advance over experimental vertical flight.
Chapter · 2:55-5:23
Why a practical helicopter took decades
Sikorsky spent 26 years between the company's founding in 1923 and the S-55's first flight in 1949, a measure of how slowly practical rotary-wing aviation developed.