{"type":"programs","slug":"1942-flying-pancake","title":"Flying Pancake Program","url":"https://disclosdex.com/programs/1942-flying-pancake","description":"Experimental aircraft development program that produced the V-173 and XF5U-1 prototypes featuring a revolutionary circular wing design","date":"1942-11-23T00:00:00.000Z","tags":["Craft"],"updated":"2025-06-13T13:26:43.000Z","connectionCount":0,"content":{"markdown":"## Origins and Context\n\nCharles H. Zimmerman developed the Flying Pancake concept from 1933-1937 while working at NACA Langley Field.[^1] The design featured a circular wing with propellers at the wingtips to minimize drag and enable extremely short takeoff and landing capabilities.[^2]\n\n## Program Structure\n\nThe program consisted of two phases: the wooden V-173 proof-of-concept aircraft and the all-metal XF5U-1 fighter prototype.[^3] The V-173 first flew on November 23, 1942, powered by two 80-hp Continental A-80 engines,[^4] while the XF5U-1 used more powerful 1,600-hp Pratt & Whitney R-2000-7 engines.\n\n## Legacy\n\nThe V-173 completed 131 flight hours across 199 flights, proving the viability of Zimmerman's circular wing concept.[^5] Though the XF5U-1 showed promise with projected speeds of 425 mph, the Navy canceled the program in March 1947 as jet technology superseded propeller-driven aircraft.[^6]\n\n[^1]: [Vought Heritage, \"V-173 Flying Pancake\"](https://www.vought.org/products/html/v-173.html); [NASA, \"Charles H. Zimmerman\"](https://www.nasa.gov/history/charles-h-zimmerman/).\n\n[^2]: [NASA, \"Charles H. Zimmerman\"](https://www.nasa.gov/history/charles-h-zimmerman/).\n\n[^3]: [Vought Heritage, \"V-173 Flying Pancake\"](https://www.vought.org/products/html/v-173.html); [SAE Technical Paper 470229, \"Experiences of an Aircraft Manufacturer with Sandwich Material\"](https://saemobilus.sae.org/papers/experiences-aircraft-manufacturer-sandwich-material-470229).\n\n[^4]: [Vought Heritage, \"The V-173 Aircraft\"](https://www.vought.org/special/html/sv1732.html).\n\n[^5]: [Vought Heritage, \"The V-173 Aircraft\"](https://www.vought.org/special/html/sv1732.html).\n\n[^6]: [Vought Heritage, \"XF5U-1 Flying Pancake\"](https://www.vought.org/products/html/xf5u-1.html); [Vought Heritage, \"XF5U-1 Specifications\"](https://www.vought.org/products/html/xf5u-1spec.html).","readingTime":"1 min read"},"relatedRecords":[],"citation":{"canonicalUrl":"https://disclosdex.com/programs/1942-flying-pancake","title":"Flying Pancake Program","publisher":"Disclosdex","retrievedFrom":"https://disclosdex.com/api/v1/programs/1942-flying-pancake","license":"CC-BY-4.0"}}