US Patent 7905083 Turbofan engine assembly and method of assembling same

A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a booster compressor coupled upstream from the core gas turbine engine, an intermediate-pressure turbine coupled to the booster compressor, the intermediate-pressure turbine disposed downstream from the core gas turbine engine, a counter-rotating fan assembly disposed upstream from the booster compressor, the counter-rotating fan assembly comprising a first fan configured to rotate in a first direction and a second fan configured to rotate in an opposite second direction, and an intermediate-pressure turbine disposed downstream from the core gas turbine engine, wherein the intermediate-pressure turbine drives the booster compressor and the second fan assembly. A method of assembling the above turbofan engine assembly is also described herein.