Air Enthusiast 1971-12
In print
One of the stages in the evolution of the Sikorsky VS-300, the first practical helicopter developed by Igor Sikorsky. The VS-300 on its first flight on 14 September 1939;
One of the stages in the evolution of the Sikorsky VS-300, the first practical helicopter developed by Igor Sikorsky. The VS-300 with a single horizontal tail rotor in 1941.
One of the stages in the evolution of the Sikorsky VS-300, the first practical helicopter developed by Igor Sikorsky. The VS-300 after the addition of outrigged tail rotors in 1940