A compound engine assembly (10, 210, 310) comprising: an engine core; a turbine section having an inlet in fluid communication with an outlet of the engine core, the turbine section including at least one turbine rotor (26', 27') connected to a turbine shaft, the turbine shaft in driving engagement with the engine shaft; a compressor having an outlet in fluid communication with an inlet of the engine core, the compressor including at least one compressor rotor in driving engagement with at least one of the turbine shaft and the engine shaft; a casing (21, 321, 321') connected to the turbine section, the compressor and the engine core; and a mount cage for mounting the compound engine assembly (10, 210, 310) to an aircraft, the mount cage including a plurality of struts (106, 106', 106", 206, 206', 206") connected to mounts attached to the casing (21, 321, 321') outside of a hot zone including the turbine section, the struts (106, 106', 106", 206, 206', 206") being separated from the hot zone by at least one firewall (63, 65, 67, 69); characterized in that: the engine core includes at least one internal combustion engine in driving engagement with the engine shaft; the inlet of the turbine section is in fluid communication with the outlet of the engine core through at least one exhaust pipe, the hot zone further includes the at least one exhaust pipe and a part of the engine core adjacent the at least one exhaust pipe; and the casing (21, 321, 321') is a casing (21, 321, 321') of a gearbox module (20, 220, 320, 320'), the compressor being located on one side of the casing (21, 321, 321'), the turbine section and engine core being located on the opposed side of the casing (21, 321, 321'), the turbine shaft extending through the gearbox module (20, 220, 320, 320') and being in driving engagement with the engine shaft through a gear train (68, 368, 368') of the gearbox module (20, 220, 320, 320'), the at least one compressor rotor being connected to the turbine shaft. an engine core; a turbine section having an inlet in fluid communication with an outlet of the engine core, the turbine section including at least one turbine rotor (26', 27') connected to a turbine shaft, the turbine shaft in driving engagement with the engine shaft; a compressor having an outlet in fluid communication with an inlet of the engine core, the compressor including at least one compressor rotor in driving engagement with at least one of the turbine shaft and the engine shaft; a casing (21, 321, 321') connected to the turbine section, the compressor and the engine core; and a mount cage for mounting the compound engine assembly (10, 210, 310) to an aircraft, the mount cage including a plurality of struts (106, 106', 106", 206, 206', 206") connected to mounts attached to the casing (21, 321, 321') outside of a hot zone including the turbine section, the struts (106, 106', 106", 206, 206', 206") being separated from the hot zone by at least one firewall (63, 65, 67, 69); characterized in that: the engine core includes at least one internal combustion engine in driving engagement with the engine shaft; the inlet of the turbine section is in fluid communication with the outlet of the engine core through at least one exhaust pipe, the hot zone further includes the at least one exhaust pipe and a part of the engine core adjacent the at least one exhaust pipe; and the casing (21, 321, 321') is a casing (21, 321, 321') of a gearbox module (20, 220, 320, 320'), the compressor being located on one side of the casing (21, 321, 321'), the turbine section and engine core being located on the opposed side of the casing (21, 321, 321'), the turbine shaft extending through the gearbox module (20, 220, 320, 320') and being in driving engagement with the engine shaft through a gear train (68, 368, 368') of the gearbox module (20, 220, 320, 320'), the at least one compressor rotor being connected to the turbine shaft. the engine core includes at least one internal combustion engine in driving engagement with the engine shaft; the inlet of the turbine section is in fluid communication with the outlet of the engine core through at least one exhaust pipe, the hot zone further includes the at least one exhaust pipe and a part of the engine core adjacent the at least one exhaust pipe; and the casing (21, 321, 321') is a casing (21, 321, 321') of a gearbox module (20, 220, 320, 320'), the compressor being located on one side of the casing (21, 321, 321'), the turbine section and engine core being located on the opposed side of the casing (21, 321, 321'), the turbine shaft extending through the gearbox module (20, 220, 320, 320') and being in driving engagement with the engine shaft through a gear train (68, 368, 368') of the gearbox module (20, 220, 320, 320'), the at least one compressor rotor being connected to the turbine shaft.