A fuel tank inerting system is provided including an air flow comprising air from a first source having a first temperature and air from a second source having a second temperature. The second temperature is cooler than the first temperature. At least one separating module is configured to separate an inert gas from the air flow.

Cabin outflow temperature control systems and methods for use on aircraft are described. The systems include an aircraft cabin, a heat load source, a heat exchanger configured to receive cabin outflow air from the aircraft cabin and heat load discharge air, the heat exchanger configured to enable thermal transfer from the heat load discharge air to the cabin outflow air to generate high temperature cabin outflow air and low temperature discharge air as outputs from the heat exchanger, and one or more downstream operation systems configured to receive the high temperature cabin outflow air and perform a downstream operation using said high temperature cabin outflow air.

A fuel tank inerting system is provided including an air flow comprising air from a first source having a first temperature and air from a second source having a second temperature. The second temperature is cooler than the first temperature. At least one separating module is configured to separate an inert gas from the air flow.

A ram air system for an aircraft having an engine and a fuselage with an outer mold line. The ram air system includes an engine air pathway having an opening in the outer mold line defining an engine inlet. The engine air pathway is configured to supply operating air for combustion in the engine. An auxiliary air pathway includes a first intake disposed inside the outer mold line in the engine inlet and a second intake disposed externally to the engine air pathway. The auxiliary air pathway is configured to draw in cooling air to cool ancillary aircraft components from at least one of the first intake and the second intake based on the airspeed of the aircraft.

An aircraft fuel tank inerting system includes an inlet, an oxygen absorption unit, and a vent to discharge oxygen from the system. The inlet may be configured to be in fluid communication with a ullage of a fuel tank. In embodiments, the oxygen absorption unit is in communication with the inlet and includes a chamber, a temperature reversible oxygen absorption medium within said chamber, and a temperature controller for selectively heating or cooling the medium. The reversible oxygen absorption medium may be a medium which absorbs oxygen by chemisorption.

An aircraft fuel system architecture which reduces the fleet-wide flammability exposure of the fuel tanks. In one embodiment, the aircraft center fuel tank fuel is cooled at certain times in a flight to reduce its flammability exposure to be similar to that of an unheated conventional metal wing fuel tank. Aircraft fuel tanks that have adjacent heat sources are also insulated to minimize heat flow into the fuel. Fuel tanks that have lower cooling properties, such as composite wing tanks are cooled at certain times during flight such that their temperatures are reduced to be similar to metal wing tanks when the fuel is flammable. A fuel tank that is pressurized relative to outside pressure at altitude having a lower flammability exposure than unpressurized tanks is combined with the cooling of fuel in the tank to reduce the fleet-wide flammability exposure of the fuel tank to be similar to that of an unpressurized metal wing tank. Fuel is cooled by recirculating flow from a tank, passing through a heat exchanger and returning to the tank to be cooled. The heat exchanger is optionally cooled by flow of air from the outside of the aircraft, or by conditioned air from the aircraft environmental control system. The system is controlled by start and stop of fuel flow to the various tanks by means of a system controller. The controller uses sensors in the fuel tanks to command flow only when required to reduce the flammability exposure of the fuel tanks.

An environmental control system for an aircraft according to an example of the present disclosure includes a first turbine coupled to an engine and a second turbine coupled to a compressor. One or more ducts are configured to provide bleed air from the engine to the first and second turbines and the compressor such that the first and second turbines and the compressor condition the bleed air. A method of conditioning air is also disclosed.

An electronics cooling system for an aircraft includes a heat exchanger comprising a coolant circuit, an air circuit, and a fuel circuit such that each of the circuits is in thermal communication with at least one of the other circuits. The coolant circuit is in thermal communication with one or more aircraft electronics. The air circuit is in fluid communication with at least one air source. The fuel circuit is in fluid communication with a fuel tank between the fuel tank and an engine of the aircraft.

An integrated fuel and environmental control system is provided and includes a first heat exchanger in which fuel and oil thermally communicate and a second heat exchanger disposable in a super-cooled fluid flow. The second heat exchanger is receptive of at least one of the fuel and oil from the first heat exchanger whereby the at least one of the fuel and oil thermally communicate with the super-cooled fluid flow. The second heat exchanger is also receptive of a second fluid whereby the second fluid thermally communicates with the super-cooled fluid flow downstream from the thermal communication of the super-cooled fluid flow with the at least one of the fuel and oil.

A fuel storage system is disclosed having a fuel tank configured to store a liquid fuel; a controllable pressure source for altering the pressure in an ullage space of the fuel tank; and a controller. The controller is configured to determine a target pressure for the ullage space at a given time based on information relating to a temperature of fuel inside the fuel tank at the given time; and to control the pressure source such as to cause the pressure in the ullage space to be substantially equal to the target pressure.