A transition duct defining an airflow pathway between a low pressure compressor and a high pressure compressor of a gas turbine engine is disclosed. The transition duct may comprise an inner wall and an outer wall located radially outward of the inner wall with respect to a central axis of the gas turbine engine. It may further comprise a first bend configured to turn the airflow radially inward with respect to the central axis, and a turning vane located at the first bend between the inner wall and the outer wall. The turning vane may be configured to assist the first bend in turning the airflow radially inward.