It 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 SikorskyThe helicopter appeared so reluctant to fly forward that we even considered turning the pilot's seat around and letting it fly backward.
Igor SikorskyAccording to recognized aero technical tests, the bumblebee cannot fly because of the shape and weight of his body in relation to the total wing area. The bumblebee doesn't know this, so he goes ahead and flies anyway.
Igor Sikorsky