Patent ID: 7882693

Claim:
A method of assembling a turbofan engine assembly comprises: providing a core gas turbine engine including a high-pressure compressor, a combustor disposed downstream from the high-pressure compressor, and a high-pressure turbine disposed downstream from the combustor, the high-pressure turbine being coupled to the high-pressure compressor by a first shaft; drivingly coupling a first gearbox to a second shaft of a low-pressure turbine, the first gearbox being disposed upstream from the core gas turbine engine, the low-pressure turbine being disposed downstream of the high-pressure turbine, and the second shaft being concentric with the first shaft; coupling a first fan assembly to the first gearbox; coupling a second gearbox to the first gearbox such that during operation the second gearbox is driven by the first gearbox; and coupling a booster compressor to the second gearbox, the booster compressor being disposed downstream from the first fan assembly, wherein the booster compressor rotates in a rotational direction opposite to a rotational direction of the first fan assembly.