Keywords: HRP-1s in flight NAN7-49.jpg U S Marines Corps Piasecki HRP-1 helicopters in flight in 1949 U S Navy Naval Aviation News July 1949 http //www history navy mil/nan/backissues/1940s/1949/Jul49 pdf 1949 USN PD-USGov-Military-Navy Piasecki HRP Rescuer |