This machine was a failure to the extent that it could not fly. In other respects it was a very important and necessary stepping stone.
Igor SikorskyIt would be right to state that, with the successful flight of the XR-4 in the summer of 1942, the helicopter became a reality in the United States.
Igor SikorskyIf you are in trouble anywhere in the world, an airplane can fly over and drop flowers, but a helicopter can land and save your life.
Igor SikorskyIt is like a dream to feel the machine lift you gently up in the air, float smoothly over one spot.
Igor Sikorsky