Planet Models 129 Republic XF-91 Thunderceptor

The Republic XF-91 Thunderceptor was a prototype American-made fighter with an all-metal mid-wing structure. The propulsion was provided by a single General Electric J47-GE-3 turbojet engine and four auxiliary rocket engines Reaction Motors XLR11-RM-9 . The flight of the prototype took place in 1949 - the machine never entered mass production. The deck armament was to consist of 4 20 mm cannons.

The Republic XF-91 Thunderceptor was created on the wave of fascination with the oblique wing, which took place in the second half of the 1940s. Airplanes with such wings could achieve high speeds in horizontal and diving flight, but they were characterized by worse longitudinal stability than machines with a traditional wing. A solution to this problem was tested on the XF-91 in the form of the so-called a divergent wing, i.e. one that is wider at the ends than at the point where it meets the fuselage. The machine turned out to be successful, and what's more, in 1951 during the tests it was the first US Air Force fighter to exceed the speed of sound! The XF-91 Thunderceptor, however, was complicated to manufacture, was not suitable for use in all weather conditions, and had worse performance than the F-102 Delta Dagger or the F-106 Delta Dart. As a result, it was not intended for mass production. Only two prototypes of this aircraft were built.