A gas turbine engine includes a compressor with an inner casing and an outer casing. The inner casing defines a primary flow path for airflow through the compressor, the inner casing and the outer casing define a bleed air cavity therebetween. The inner casing at least partially defines a first bleed air channel between the primary flow path and the first bleed air cavity. The first bleed air channel is defined between a first wall and a second wall, wherein the first wall is upstream from the second wall. The first wall includes a plurality of holes in fluid communication with the primary flow path and fluidly coupled to a suction manifold. The plurality of holes is configured to energize a fluid boundary layer along the first wall.