5 Fast Facts On The 1st US Army Helicopter Deployment In WW2
But the United States was not far behind and by January 1943, the US Army had introduced its first successful helicopter (the ...
Sikorsky R-4B Hoverfly: The US Army Air Force's 1st Helicopter
The Sikorsky R-4 first took to the skies in January 1942, and it expanded upon the capabilities of the experimental VS-300, a ...