One of Langley's Sikorsky YR-4B/HNS-1 helicopters is seen in the 30 x 60 Full Scale Tunnel. The technician is setting up camera equipment for stopped-action rotor-blade photos. Sikorsky built hundreds of R-4 helicopters during World War II. It was the first mass-produced helicopter. (Image # L-40416)

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Size: 2145px × 1555px
Photo credit: © ART Collection / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: full, helicopter, hns-1, langley, naca, scale, sikorsky, tunnel, yr-4b