High Quality Content by WIKIPEDIA articles! Originally designated XF-106, the project and its resultant prototype aircraft were renamed XF-84H, suggesting it was a mere F-84 variant, rather than an entirely new type. The initial inception for the program came from a U.S. Navy requirement for a carrier fighter not requiring catapult assistance, although the USAF Wright Air Development Center was the key sponsor of the project. The XF-84H was created by modifying a F-84F Thunderstreak aircraft. The engine was changed to an Allison XT-40-A-1, capable of 5,850 hp (4,362 kW). An afterburner was installed though never used, which could increase power to 7,230 hp (5,391 kW). The 12 ft diameter Aeroproducts propeller consisted of three steel, square-tipped blades turning at a constant 3,000 rpm, with the tips travelling at approximately Mach 1.18.