How The Thunderscreech Became The Loudest Plane Ever Made

The Republic XF-84H Thunderscreech is probably one of the most infamous jets the US has ever produced. Although it looked normal, it didn’t sound normal. In fact, it was so loud that it often made it ground crew physically ill!

Loudest Plane Ever?

The Thunderscreech became so loud that the power of the sound waves emitting from the plane could knock people off.

On one occasion, it even caused an engineer who worked on a plane nearby to suffer a seizure. 

Inception

The XF-84H was built to combine high speed and fast acceleration.

It was fitted with an Allison T40 turboprop engine, with an output of 5,850 hp, making it one of the world’s most powerful engines for a time.

Unfortunately, there were only two XF-84Hs built.

Deafening Noise

The jet’s speed was controlled by the rotating propeller blades. However, the constant speed the propeller turned was supersonic. The blades spun so fast that the outer 60 cm of the blades traveled faster than sound.

Since the propeller’s speed didn’t change, the sonic shock wave emanated out laterally from the propeller up to hundreds of meters.

As a result, one can hear the noise even over 25 miles away. In fact, it was so loud that could knock a man off if he walked through the shock waves. 

Effects

Reportedly, the ground crew would become nauseous just by being near the jet. 

Sensitive instruments at the Edwards AFB control tower were also put at risk because of the noise. Eventually, the airbase gave up on the XF-84H and was towed out to Rogers Dry Lake.

Looking at the effects it had on anyone in the vicinity of the Thunderscreech, it’s likely that it was the loudest plane ever made.