The present disclosure is directed to a gas turbine engine defining a radial direction, a longitudinal direction, and a circumferential direction, an upstream end and a downstream end along the longitudinal direction, and an axial centerline extended along the longitudinal direction. The gas turbine engine includes a low pressure (LP) turbine defining an outer flowpath. The outer flowpath defines a first outer flowpath radius at an upstream-most end of the LP turbine, a last outer flowpath radius disposed at a downstream-most end of the LP turbine, a middle outer flowpath radius disposed therebetween along the longitudinal direction. The middle outer flowpath radius is greater than the last outer flowpath radius.