An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A stabilizer assembly and a boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The stabilizer assembly includes a stabilizer and a root fillet extending between the stabilizer and the fuselage. The root fillet defines a flow directing surface configured for urging a flow of boundary layer air upward along the vertical direction. In addition, an airflow modifying element may protrude from a surface of the fuselage or the root fillet, the airflow modifying element being configured for directing or reducing swirl in the flow of boundary layer air.