Ah, good ol' Thunderscreech[0]! > The XF-84H was almost certainly the loudest aircraft ever built, earning the nickname "Thunderscreech" as well as the "Mighty

Ah, good ol' Thunderscreech[0]! > The XF-84H was almost certainly the loudest aircraft ever built, earning the nickname "Thunderscreech" as well as the "Mighty Ear Banger". On the ground "run ups", the prototypes could reportedly be heard 25 miles (40 km) away. Unlike standard propellers that turn at subsonic speeds, the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down. [0] https://en.m.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech#Noise https://en.m.wikipedia.org/wiki/Republic_XF-84H_Thunderscree...