Keywords: XF4F-3 during test flight, 1939.jpg Grumman XF4F-3 prototype Bureau 0383 photographed during flight testing 21 July 1939 http //www history navy mil/photos/images/h97000/h97482 jpg Naval Historical Center 1939-07-21 US Navy Employee PD-USGov-Military-Navy Grumman F4F Wildcat |