Chance Vought XF5U-1 Flying Pancake Fighter

The Vought XF5U “Flying Flapjack” was an experimental U.S. Navy fighter aircraft designed by Charles H. Zimmerman during World War II. This unorthodox design consisted of a flat, somewhat disk-shaped body (hence its name) serving as the lifting surface. Two piston engines buried in the body drove propellers located on the leading edge at the wingtips.

The XF5U design was promising: specifications given at the time promised the ability to hover like a helicopter while having an airspeed range of 0 to 550 mph. However, it came at the time when the United States Navy was switching from propeller driven to jet propelled aircraft. By 1946 the XF5U-1 project was already long over its expected development time, and well over budget. With jet aircraft coming into service the Navy finally canceled the project on 17 March 1947 and the prototype aircraft (V-173) was transferred to the Smithsonian Museum for display. Although two aircraft were constructed, a lone XF5U-1 underwent ground runs but never overcame vibration problems. Taxi trials at Vought’s Connecticut factory culminated in short “hops” that were not considered true flights. The only completed XF5U-1 proved to be so structurally solid that it had to be destroyed by a wrecking ball.