hey crammed a jet engine into a fighter plane, then bolted a propeller onto the front. Once it took off, the blade tips spun faster than sound, firing shockwaves every time they passed through the air. Because it rotated thousands of times per minute, more than a hundred sonic booms could hit in just one second. The force was so brutal it made nearby workers lose balance and throw up. The program was canceled, and one of history’s loudest aircraft now rests silently in a museum.