[3] In developing the concept of rotary-wing flight, Sikorsky was the first to introduce a single engine to power both the main and tail rotor systems.

The only previous successful attempt at a single-lift rotor helicopter, the Yuriev-Cheremukhin TsAGI-1EA [ru] in 1931 in the Soviet Union, used a pair of uprated, Russian-built Gnome Monosoupape rotary engines of 120 hp each for its power.

[4][5] For later flights of his VS-300, Sikorsky also added a vertical airfoil surface to the end of the tail to assist anti-torque but this was later removed when it proved to be ineffective.

[6] Sikorsky fitted utility floats (also called pontoons) to the VS-300 and performed a water landing and takeoff on 17 April 1941, making it the first practical amphibious helicopter.

The VS-300 was modified over a two-year period, including the removal of the two vertical tail rotors, in 1941, when a new cyclic control system gave it much-improved flight behavior.