Almost by accident, its designers stumbled upon the most maneuverable aerodynamic design in history. Mathematically, the XF-41's airframe was in a "zone of perfection" that made the plane able to pull off any maneuver with ease. It was impossible to stall the plane and it could make a 180 degree turn in about a second. The plane could not carry ordinance, the slightest adjustment of the plane's airframe would negate the 'zone of perfection" and the entire aircraft would become completely unstable. Therefore, the aircraft was also very sensitive to combat damage.
A squadron of five XF-41s operated from an unnamed carrier in the pacific where they were deployed in utmost secrecy, no Japanese aircraft spotted could be allowed to get away, and any crew of an allied aircraft would be taken in for questioning if it they spotted a XF-41. They could be held in custody till the end of the war in some cases.
Despite it's incredible qualities, it came too late. The Navy decided to keep the project secret, even though it was obsolete for most military purposes. One of the designers said it was akin to, "inventing a supersonic car, then having somebody invent a time machine the next morning".
(note: this aircraft and its story is fictional)-Andrew