The XF3U was designed to meet the
Bureau of Aeronautics 1932
Design Specification No. 111, which called for a high-performance fighter with a fixed
undercarriage and powered by a
Pratt & Whitney R-1535 Twin Wasp Junior air-cooled radial engine. Of the seven proposed aircraft the Berliner-Joyce XF3J-1, Curtiss XF12C-1, Chance Vought XF3U-1 and the
Douglas XFD-1 were chosen and prototypes of each aircraft were ordered on 30 June 1932. The XF3U was the first all-metal aircraft produced by Vought. The aircraft was also equipped with an enclosed
cockpit. During flight testing in 1933, it outperformed the Douglas entry and was chosen the winner. The XF3U was also redesignated the XSBU, meaning "scout bomber." ==Operational history==