"Everyman's Jet Engine" - Why Valveless Pulsejets? All-weather operation without special care or modifications A few experimentors (most notably Eric Beck of Beck Technologies, Inc.) have shown that valveless pulsejets can be readily started and run in outdoor air temperatures far below freezing, and also during rain- and snow-storm conditions without special protection from the elements. Airborne water droplets, snowflakes and ice crystals pass through the engine with no noticeable negative effects on operation. The only obvious exception is that the engine's intake and tailpipe openings will probably need to be protected from the influence of strong or gusty winds during starting.