Integrated tailcone muffler assemblies and methods for using the same

Methods integrated tailcone muffler (ITM) is provided for minimizing noise generated while discharging pressurized air from one or more aircraft gas turbine engines. The ITM comprises a tail cone defining a conical backing cavity, the conical backing cavity having a large forward end and a narrow aft end and a porous exhaust liner with a first end and a second end, the first end coupled to an oil cooler eductor discharge plenum of a first gas turbine engine of the one or more gas turbine engines and a second end discharging to atmosphere via the narrow aft end of the conical backing cavity. The ITM further comprises a bleed air discharge conduit configured to discharge pressurized bleed air from the one or more gas turbine engines into the conical backing cavity and a firewall bulkhead defining the large forward end of the conical backing cavity, defining a first aperture passing the cylindrical porous exhaust liner and defining a second aperture passing the bleed air discharge conduit, the firewall bulkhead extending radially from both of the cylindrical porous exhaust liner and the bleed air discharge conduit.