Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Uploaded on Mar 1, 2009
The Sikorsky R-4 was the world's first mass-produced helicopter and the United States Air Force's first service helicopter.
The VS-316, was developed from the famous experimental VS-300 helicopter, invented by Igor Sikorsky and publicly demonstrated in 1940. The VS-316 was designated the XR-4, under the United States Army Air Forces' series for "Rotorcraft". The XR-4 made its initial flight on 13 January 1942 and as a result of its successful flight tests, the United States Army Air Forces ordered three YR-4As and 27 YR-4Bs.