An environmental control system that includes a first environmental control system pack, a first recirculation fan assembly, and a cabin air sensor unit. The first environmental control system pack is arranged to provide conditioned air to an aircraft cabin. The first recirculation fan assembly is arranged to recirculate a first cabin air fluid flow back to the aircraft cabin. The cabin air sensor unit is arranged to provide a first air quality signal indicative of an air quality of the first cabin air fluid flow to a controller.

There is provided an apparatus for preparing a ventilation gas mixture for pilots and crew of aircraft, the apparatus comprising a first gas mixer feed configured to receive exhaled air from a person, wherein the exhaled air comprises carbon dioxide, a second gas mixer feed configured to receive an air mixture comprising at least one gas, and a gas mixing device configured to receive the exhaled air and the air mixture from the first and second gas mixer feeds and combine the exhaled air with the air mixture in the gas mixing device to form a ventilation gas mixture. The apparatus further comprises a pressure adjuster configured to increase the pressure of the exhaled air in the first gas mixer feed so that it substantially matches the pressure of the air mixture in the second gas mixer feed.

An environmental control system in a vehicle includes a pressurized tank of nitrox, which is a mixture of nitrogen and oxygen, and a delivery valve to block or allow a flow of the nitrox from the pressurized tank to a cabin of the vehicle. The environmental control system also includes a controller to control the delivery valve based on a total pressure or an oxygen partial pressure in the cabin.

A gas turbine engine includes a compressor section and a turbine section operably coupled to the compressor section. The gas turbine engine further includes a means for selectively releasing a cooling fluid flow produced at a cryogenic temperature and a plumbing system in fluid communication with the means for selectively releasing the cooling fluid flow. The plumbing system is configured to route the cooling fluid flow to one or more of the compressor section and the turbine section.

A fuel oxygen reduction unit assembly for a fuel system is provided. The fuel oxygen reduction unit assembly includes: a fuel oxygen reduction unit located downstream from the fuel source and defining a stripping gas flowpath and a liquid fuel flowpath, the fuel oxygen reduction unit comprising a means for transferring an amount of oxygen from a liquid fuel flow through the liquid fuel flowpath to a gas flow through the stripping gas flowpath; and an oxygen conversion unit in flow communication with the stripping gas flowpath configured to extract a flow of oxygen from a gas flow through the stripping gas flowpath, the oxygen conversion unit defining an oxygen outlet configured to provide the extracted flow of oxygen to an external system.

A fuel system is provided for an aircraft having a fuel source. The fuel system includes a fuel oxygen reduction unit defining a liquid fuel supply path, a stripping gas supply path, a liquid fuel outlet path, and a stripping gas return path, wherein the stripping gas return path is in airflow communication with the fuel source.

An apparatus for preparing a ventilation gas mixture to a user comprises: a gas mixing device configured to receive oxygen through a first gas feed, the gas mixing device being further configured to received exhaled air from a person; a gas reservoir configured to receive the exhaled air from the gas mixing device through a second gas feed, wherein the gas reservoir is further configured to re-supply the exhaled air to the gas mixing device through the second gas feed; an altitude sensor configured to determine altitude information; a control system configured to receive the altitude information from the altitude sensor and further configured to control the flow of oxygen through the first gas feed based on the received altitude information; wherein the gas mixing device is arranged to combine the oxygen received through the first gas feed with the re-supplied exhaled air received through the second gas feed in order to prepare a ventilation gas mixture.

An emergency oxygen system for aircraft comprising: a breathing gas supply circuit to be connected upstream to a source of breathing gas and downstream to at least one mask, a flow control valve configured to adjust the flow of breathing gas supplied to the mask, an electronics board configured to control the flow control valve, a power source, a switching device interposed between the power source and the electronics board, the switching device comprising a switch configured to have a first state in which power from the power source is supplied to the electronics board and a second state in which the electronics board is not supplied with power from the power source.

A cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for collecting liquid air. The first air cycle machine is operable to output a cooling air stream based on a first air source. The second air cycle machine is operable to output a chilled air stream at a cryogenic temperature based on a second air source cooled by the cooling air stream of the first air cycle machine. An output of the second air cycle machine is provided to the means for collecting liquid air.

Described herein are a system for providing oxygen to oxygen masks in an aircraft, and an associated method for regulating the oxygen flow in an efficient manner. The system has an oxygen tank, oxygen masks, first and second oxygen lines, and an electrically controllable valve. The valve is coupled to the oxygen tank and the two oxygen lines. The oxygen masks are coupled to the oxygen lines downstream of the valve to accommodate the transfer of oxygen from the oxygen tank via the valve. In a working state when an electrical signal is applied the valve produces a connection between the oxygen tank and the first oxygen line when required, and permanently prevents a connection between the oxygen tank and the second oxygen line. When in a rest state, the valve produces a permanent connection between the oxygen tank and the second oxygen line.