Abstract: A system and method of air routing for an air-breathing engine is disclosed. Air enters the front of a scramjet engine via an inlet region. The inlet region is connected to a duct, which extends to the aft region of the scramjet engine where a base area of the air-breathing engine is located. The duct walls are formed using a porous structure fluidly coupled to apertures in both the inlet region and the base area. The air that enters the inlet region is routed through the porous walls of the duct and expelled at the base area. This expulsion of air through apertures in the base area causes base pressure to increase, which reduces base drag. Additionally, pulling air through perforations in the inlet region reduces the amount of low momentum flow entering the engine, which improves engine performance.