Space History Photo: Sikorsky HNS-1 (YR-4B)
Friday, February 15, 2013 - 09:30
in Astronomy & Space
One of Langley's Sikorsky YR-4B/HNS-1 helicopters is seen in a wind tunnel.
One of Langley's Sikorsky YR-4B/HNS-1 helicopters is seen in a wind tunnel.