We need jet engines to have suction force, for example, if a kerbal comes within 5m of the center of a Goliath engine facing fowards, they will get sucked in and be killed if the engine is on idle. If the engine is full power, suction force starts 15m away from the center of the engine and increases the closer you get, until a kerbal gets within 7m of the center of the engine, which is when they will get sucked in. If parts are light enough they will get sucked in as well. I think that parts 0.2