A system for cooling a motor operating within an aircraft system includes an enclosure receiving ram air from a first ram air duct and discharging ram air to a second ram air duct to form a cooling path. The second ram air duct is discrete and independent from the second ram air duct. The system can discharge ram air between a heat exchanger and a fan within the second ram air duct that define a reduced or negative pressure region within the second ram air duct.

An aircraft cabin blower system comprises a cabin blower including a compressor configured to provide air to a cabin of the aircraft; a variable drive system configured to drive the compressor and including an electric variator and a summing gearbox; and a main transmission configured, when operating in a blower mode, to receive mechanical power from a gas turbine engine and input mechanical power to the summing gearbox in a forward direction; and configured, when operating in a starter mode, to receive mechanical power from the summing gearbox and input mechanical power to the gas turbine engine. The aircraft cabin blower system further includes a first one-way rotation device adapted to permit free rotation of the main transmission in the forward direction and to prevent rotation of the main transmission in a reverse direction opposite to the forward direction.

An aircraft air conditioning system comprising an ambient air line, for ambient air to flow through, connected to supply ambient air to a mixer of the aircraft air conditioning system. An ambient air compressor is arranged in the ambient air line for compressing the ambient air flowing there through. A refrigerating apparatus comprises a refrigerant circuit for a refrigerant to flow through, including a refrigerant compressor arranged in the refrigerant circuit. The refrigerant circuit is coupled thermally to the ambient air line to transfer heat from the ambient air to the refrigerant before the ambient air is supplied to the mixer. A cabin exhaust air turbine is connected to a cabin exhaust air line, is coupled to the ambient air compressor arranged in the ambient air line, and is configured to expand the cabin exhaust air flowing through the cabin exhaust air line and to drive the ambient air compressor.

An engine driven environmental control system (ECS) air circuit includes a gas turbine engine having a compressor section. The compressor section includes a plurality of compressor bleeds. A selection valve selectively connects each of said bleeds to an input of an intercooler. A second valve is configured to selectively connect an output of said intercooler to at least one auxiliary compressor. The output of each of the at least one auxiliary compressors is connected to an ECS air input.

An air cycle machine is provided. The air cycle machine can be included an environmental control system of an aircraft. The air cycle machine can include a turbine comprising a plurality of inlet gas flow paths, a compressor driven by the turbine from a shaft, and a fan driven by the turbine from the shaft.

The disclosure describes a system that includes an auxiliary power unit (APU), an APU throttle valve, and an environmental control system (ECS) bypass valve. The APU is configured to receive cabin discharge air from an aircraft cabin and receive ECS supply air from an air pressurization system (APS). The APU throttle valve is configured to control flow of cabin discharge air from the cabin to the APU. The ECS bypass valve configured to control flow of ECS supply air from the APS to the APU.

An architecture for an aircraft comprises two air-conditioning systems, two converters, each intended to supply one of the air-conditioning systems, and at least one first electric machine which starts up a first main engine of the aircraft. The electrical architecture is configured such that the two converters can together supply the first electric machine. A method of operating the architecture is also provided.

The invention relates to an electrical air conditioning system for air conditioning a cabin (10) of an aircraft comprising a source (11) of fresh air, a dynamic air circulation duct (12), a motorized compressor (13) comprising an air inlet connected to said source of fresh air, and an air outlet connected to a primary cooling exchanger (PHx) housed in said dynamic air duct; an air cycle turbomachine (14) comprising at least a first compressor (15) and a first turbine (17) that are mechanically coupled to one another, said first compressor comprising an air inlet that can be connected either to said primary cooling exchanger (PHx) or to said source (11) of fresh air, and an air outlet connected to a main cooling exchanger (MHx) housed in said dynamic air duct, said first turbine (17) comprising an air inlet that can be connected either to a discharge port (54) for discharging stale air from said cabin or to said main cooling exchanger (MHx), and an air outlet that can be connected either to said cabin (10) or to an air injector (52) opening into said dynamic air duct.

A cabin blower for an aircraft, the system comprising: a cabin blower compressor; an electric machine; and a controller configured to control the cabin blower system so that: in a cabin blower mode of operation, the cabin blower compressor is driven by power extracted from one or more spools of a gas turbine engine of the aircraft and provides a flow of air to a cabin of the aircraft. The controller may be further configured to control the system so that: in a rotor bow mitigation mode of operation, the cabin blower compressor is driven by the electric machine using electrical power from an electrical power source and provides a flow of air through a core of the gas turbine engine to remove heat from the core. A method of operating a cabin blower system of an aircraft is also provided.

An air duct system is disclosed, and includes an air duct having a main body, where the main body of the air duct defines a passageway having a reflective inner surface. The air duct system also includes an ultraviolet light source configured to generate ultraviolet light. The ultraviolet light source directs the ultraviolet light along the reflective inner surface of the air duct.