A gas turbine engine (10, 10') including: an engine core including a compressor (14, 15, 44, 45), a combustor (16, 46), and a turbine (17, 18, 19, 47, 49), the compressor being connected to the turbines through a respective shaft; an accessory gearbox arranged within an accessory gearbox casing; and a cabin blower system (200-200", 400-400", 500-500", 600) adapted to be driven by the accessory gearbox and comprising: an electric variator comprising a first electrical machine connected to a drive pad of the accessory gearbox by a first shaft (234, 234') arranged along a first axis (209, 401), a second electrical machine connected to a second shaft (236, 236') arranged along a second axis (209, 402), and a power management system interconnecting the first and second electrical machines and controlling whether each of the first and second electrical machines operate as a motor or a generator; a differential gearbox having a first input connected to a drive pad of the accessory gearbox to receive drive therefrom, a second input connected to the second shaft of the second electrical machine, and an output; and a cabin blower comprising a compressor driven by the output of the differential gearbox by a third shaft (238, 238') arranged along a third axis (209, 403), the compressor comprising an air inlet and an air outlet; characterized in that the cabin blower, the first electrical machine, the second electrical machine and the differential gearbox are configured as modules, and in that the first and second electrical machines (212, 214) are arranged on a first side of the accessory gearbox casing and the cabin blower is arranged on a second side of the accessory gearbox casing opposite the first side. an engine core including a compressor (14, 15, 44, 45), a combustor (16, 46), and a turbine (17, 18, 19, 47, 49), the compressor being connected to the turbines through a respective shaft; an accessory gearbox arranged within an accessory gearbox casing; and a cabin blower system (200-200", 400-400", 500-500", 600) adapted to be driven by the accessory gearbox and comprising: an electric variator comprising a first electrical machine connected to a drive pad of the accessory gearbox by a first shaft (234, 234') arranged along a first axis (209, 401), a second electrical machine connected to a second shaft (236, 236') arranged along a second axis (209, 402), and a power management system interconnecting the first and second electrical machines and controlling whether each of the first and second electrical machines operate as a motor or a generator; a differential gearbox having a first input connected to a drive pad of the accessory gearbox to receive drive therefrom, a second input connected to the second shaft of the second electrical machine, and an output; and a cabin blower comprising a compressor driven by the output of the differential gearbox by a third shaft (238, 238') arranged along a third axis (209, 403), the compressor comprising an air inlet and an air outlet; an electric variator comprising a first electrical machine connected to a drive pad of the accessory gearbox by a first shaft (234, 234') arranged along a first axis (209, 401), a second electrical machine connected to a second shaft (236, 236') arranged along a second axis (209, 402), and a power management system interconnecting the first and second electrical machines and controlling whether each of the first and second electrical machines operate as a motor or a generator; a differential gearbox having a first input connected to a drive pad of the accessory gearbox to receive drive therefrom, a second input connected to the second shaft of the second electrical machine, and an output; and a cabin blower comprising a compressor driven by the output of the differential gearbox by a third shaft (238, 238') arranged along a third axis (209, 403), the compressor comprising an air inlet and an air outlet; characterized in that the cabin blower, the first electrical machine, the second electrical machine and the differential gearbox are configured as modules, and in that the first and second electrical machines (212, 214) are arranged on a first side of the accessory gearbox casing and the cabin blower is arranged on a second side of the accessory gearbox casing opposite the first side.