Vought XF5U-1 Flying Flapjack

The Vought XF5U-1 was an experimental U.S. Navy fighter aircraft developed during World War II, notable for its flat, disc-like aerodynamic body. Although the project was canceled in 1947 before the prototype could fly, its unconventional shape became legendary in aviation circles. Because of its physical resemblance to a flying saucer, it is frequently cited by aviation historians and skeptics as a potential terrestrial inspiration for early UFO reports.

Its disc-like design is a primary example of experimental military aviation being linked to the origins of the flying saucer phenomenon.