An exhaust system for an APU in a gas turbine engine aircraft having a tail cone in which exhaust noise is reduced. An APU exhaust liner is attached to the APU and extending to an oval cutout at the tail cone The liner has a first constant cross section from the APU to a point proximate the tail cone, and a second, increasing cross section from the point proximate the tail cone to the liner cutout. The liner is turned toward the side of the tail. The liner cutout is further enlarged with at least one larger cutout.