An auxiliary power unit for an aircraft. It includes an air compressor coupled to an air-drawing device for drawing in air from outside the aircraft, the compressor supplying compressed air to a manifold. The manifold is configured to supply air to an environmental control system and a start-up module of at least one propulsion system of the aircraft running on hydrogen. The manifold is also configured to supply air to a fuel cell stack arranged to provide an electric generation function configured to power non-propulsive systems of the aircraft, the fuel cell stack also being supplied with hydrogen from a tank supplying hydrogen to the at least one propulsion system of the aircraft.

A system and method for improved system efficiency of an integrated power and control unit (IPCU) of an aircraft is disclosed. The system uses an open-loop cooling system and turbo machine power matching to provide wide operation range without over-sizing. In order to reduce the temperature of the air flow through the cooling heat exchanger, the cooling turbine need to expand further in the same time generating power but the power could be higher than the compressor could absorb so a generator that would convert the power and used in supplying the aircraft would result in more efficient system.

A system for an aircraft is provided. The system includes a compressing device and at least one heat exchanger. The compressing device includes a compressor, a turbine downstream of the compressor, and an electric motor coupled to the turbine and the compressor. Further, the compressor includes a high rotor backsweep. The system can be an air conditioning system.

A high efficiency multifunction power system for an aircraft is provided. The system includes an AC generator and a multifunction power converter-controller module including at least one multifunction power converter-controller. The at least one multifunction power converter-controller is configured to function as a power converter and a controller to perform multiple operation modes.

Air conditioning system for a cabin (10) of an aircraft, comprising: an air bleed device; an air cycle turbine engine (12); at least one main cooling exchanger (16); a water extraction loop (30); and a pipe (26) for distributing water extracted by said extraction loop (30), characterized in that said system further comprises means (40) for heating the water extracted by the water extraction loop so as to be able to spray the water into a ram-air channel (22) which supplies said main exchanger (16).

A method and a system are provided for monitoring the state of a heat exchanger (17) in an air circuit (5) of an aircraft (7), the heat exchanger being intended to cool the air extracted from a source of a main hot air source of the aircraft. An acquisition module (11) is configured to acquire temperature measurements taken by a probe disposed at an outlet of said heat exchanger, the acquisition being carried out when the air circuit is supplied by a secondary hot air source downstream of the heat exchanger and the main hot air source being turned off. A processor (9) is configured to select a relevant temperature measurement from the temperature measurements and to detect a possible leak in the heat exchanger (17) by comparing the relevant temperature measurement to a predetermined alert threshold.

A method of operating an environmental control system of an aircraft includes providing a first medium to the environmental control system including a compressor and a turbine and extracting work from a second medium provided to a second turbine operably coupled to the compressor to drive the compressor. The first medium is provided to the compressor and the turbine sequentially. In a first mode of operation, the first medium to be provided to a downstream load is output from the turbine and in a second mode of operation, at least a portion of the first medium to be provided to the downstream load bypasses the turbine.

An engine assembly for use as an aircraft auxiliary power unit, having internal combustion engine(s) in driving engagement with an engine shaft, a generator having a generator shaft directly engaged to the engine shaft such as to be rotatable at a same speed, a compressor having an outlet in communication with the internal combustion engine inlet, and a turbine having an inlet in communication with the internal combustion engine outlet. The turbine may be a first stage turbine, and the assembly may include a second stage turbine having an inlet in communication with the first stage turbine outlet. A method of providing electrical power to an aircraft is also discussed.

A system for driving an environmental control system (ECS) of a vehicle with ground-based electrical power may include a turbine engine on board the vehicle, coupled to the ECS to pneumatically drive the ECS, and an electric machine, on board the aircraft, mechanically coupled to the turbine engine, to drive the turbine engine. A control system such that the electric machine provides motoring assistance to the turbine engine, and that the motoring assistance is limited to match the available current from the ground-based electrical power.

An aircraft air conditioning system comprises a process air line configured to supply compressed process air provided by a process air source to an air conditioning unit of the aircraft air conditioning system and a trim air line branching off from the process air line upstream of the air conditioning unit and being configured such that trim air flows through the trim air line, the trim air having been branched off from the compressed process air flowing through the process air line. A compressor is arranged in the trim air line and is configured to compress the trim air flowing through the trim air line. A turbine of the aircraft air conditioning system is configured to drive the compressor. A cabin exhaust air line is configured to supply cabin exhaust air discharged from an aircraft cabin to the turbine for driving the turbine.