Keywords: XF9C-1 NAN4-80.jpg The Curtiss XF9C-1 Sparrowhawk prototype BuNo A8731 before being fitted with the hooking equipment in flight in early 1931 U S Navy Naval Aviation News April 1980 http //www history navy mil/nan/backissues/1980s/1980/Apr80 pdf 1931 USN PD-USGov-Military-Navy Curtiss F9C Sparrowhawk Townend rings |