The Berliner-Joyce XF3J was an American biplane fighter.
It was submitted to the United States Navy for their request for a single seat carrier based fighter powered by a 625 hp (466 kW) Wright R-1510-26 engine
The XF3J had elliptical fabric covered wings which gave it the appearance of a butterfly.
The fuselage was semi monocoque metallic with an aluminium skin.
The undercarriage was fixed, and would be the last biplane fighter without a retractable gear that the U.S. Navy would test.
The aircraft performed satisfactorily in testing, but more promising aircraft had been developed and, in September 1935, the program was terminated.