Maddox doesn’t build rockets. He builds pulse-jet engines. There’s a difference. As for the crazy part—that may be true.

This loud, pulse-combustion fire-breather is officially ... In contrast to the rotational components used in other jet engines, Wave's pulsejet eliminates the need for moving parts.

that the pulse detonation engine (PDE) promises higher efficiency than turbofan jet engines. Boeing has a proprietary pulsejet engine technology called Pulse Ejector Thrust Augmentor (PETA), while ...

Wave Engine Corporation, a company founded by the University of Maryland, has developed a modern digitally controlled pulse jet engine for drones and shipped the first batch to customers. The engine ...

Both engines would be used to propel missiles ... Some jet derivatives, such as ramjets and pulse jets, also work without compressors and turbines, but they operate differently and have limitations.