Abstract: A noise reduction kit is provided for installation on a bypass turbine engine having a core engine, an outer casing and a thrust reverser. The kit comprises a mixer downstream of the core engine for mixing fan air of the engine with the exhaust gas from the core engine to reduce the peak velocity of the exhaust gas; a structure for supporting and positioning said mixer relative to the engine; a spacer for extending the length of the exhaust gas flow path between said mixer and the thrust reverser to permit sufficient mixing of the fan air with the exhaust gas prior to reaching the thrust reverser; and an acoustic tail pipe assembly configured to define an outlet area for the engine exhaust gas flow path. The outlet area is sized and shaped to reduce pressure loss in the exhaust gas stream in an amount necessary to compensate for the pressure increase in the exhaust gas stream created by the mixer.