XF-84H Thunderscreech

The Republic XF-84H "Thunderscreech" is an American experimental turboprop aircraft derived from the F-84F Thunderstreak. Powered by a turbine engine that was mated to a supersonic propeller, the XF-84H had the potential of setting the unofficial air speed record for propeller-driven aircraft, but was unable to overcome aerodynamic deficiencies and engine reliability problems, resulting in the program's cancellation. Its name, Thunderscreech, is a reference to its extremely loud supersonic propeller.