A method for operating a turbofan engine assembly is provided. The turbofan engine assembly includes a core cowl which circumscribes the core gas turbine engine, a nacelle positioned radially outward from the core cowl, a fan nozzle duct having an area defined between the core cowl and a portion of the nacelle, a first cowl and a second cowl that define a portion of the nacelle wherein the second cowl is repositionable with respect to the first cowl, and a thrust reverser assembly wherein the second cowl surrounds the thrust reverser assembly. The method includes varying an operating speed of the fan assembly from a first operating speed to a second operating speed. The method further includes selectively positioning the second cowl between a first operational position and a second operational position to vary the area of the fan nozzle duct to facilitate improving engine efficiency at the second operating speed. The method further includes selectively positioning the second cowl between the second operational position and a third operational position to vary an amount of air flowing through the fan nozzle duct and the thrust reverser assembly, wherein the second operational position substantially prevents airflow from flowing through the thrust reverser assembly to improve the efficiency of the turbofan engine, and wherein the third operational position directs airflow through the thrust reverser assembly.