Vought-Sikorsky XR-4C at the Udvar-Hazy Center

Vought-Sikorsky XR-4C at the Udvar-Hazy Center
The XR-4 served as the prototype for the world's first mass-produced helicopter.
  • WEB10835-2008

  • Copyright/Owner: Smithsonian Institution
  • Source: National Air and Space Museum, Smithsonian Institution
  • Photographer: Dane Penland
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