Patent ID: 8726665

Claim:
An airborne mobile platform comprising: at least one turbofan engine assembly having a fan driven by a core engine, a short nacelle around the fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle; a mixer duct shell substantially coaxial with and extending forwardly into the fan exhaust duct to provide a mixer duct between the mixer duct shell and a core engine shroud of the core engine, the core engine shroud having an outer surface that partially form the fan exhaust duct, the mixer duct for mixing pressurized fan exhaust and pressurized core exhaust; and the mixer duct shell including an acoustic lining on at least a portion thereof; the acoustic lining including a honeycomb core structure and being secured to one of an inner surface or an outer surface of the mixer duct shell, the acoustic lining attenuating sound emanating from the turbofan engine assembly.