"Everyman's Jet Engine" - Why Valveless Pulsejets? Extremely easy to repair if damaged Of course we can always imagine an engine so mangled in a crash that there's no point in trying to salvage it, but repair is probably far easier for valveless pulsejets than for any other propulsion powerplant. This is due to the complete absence of internal moving parts or finely mated machined surfaces. A damaged area can often be simply hammered out straight; if not, the damaged area can be "sectioned" in the familiar manner of auto body repair. These engines should offer the minimum possible downtime in any damage situation, with sheet metal cutting and welding being the only basic procedures needed.