The invention discloses a gas turbine engine which includes a turbomachine and a fan rotatable by the turbomachine. The fan includes a plurality of fan blades. The gas turbine engine also includes anouter nacelle surrounding the plurality of fan blades and including an inner wall, the inner wall of the outer nacelle including a plurality of pre-swirl contours positioned forward of the fan bladesof the fan along an axial direction and extending inwardly along a radial direction.