An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust propulsor driven by the power source; and a wing extending from the fuselage, the vertical thrust propulsor positioned on or at least partially within the wing, the wing including a diffusion assembly, the diffusion assembly including at least one diffusion member fixed in position and located downstream of the vertical thrust propulsor for diffusing an airflow from the vertical thrust propulsor.