In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes.

In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes.

The invention concerns a method for measuring the concentration of a substance or mixture of substances and/or determining the level in a fluid with intrinsic fluorescence, preferably fuel systems. The invention also refers to the optical device suitable for implementing the method, which comprises a unit which generates light for excitation of the sample; a unit of detection of the signal emitted by the sample and a unit of signal processing. The device and method by which it is implemented also allow the determination of the spatial distribution of the substance or mixture of liquid substances and/or the fluid level in a container. One of the main applications is the measurement of the concentration of oxygen in the fuel tank of aircrafts, based on the measurement of the intrinsic fluorescence of the fuel.

Fuel tank inerting systems are provided. The systems include a fuel tank, an air source arranged to supply air into a reactive flow path, a catalytic reactor having a plurality of sub-reactors along the flow path, and a heat exchanger. The sub-reactors are arranged relative to the heat exchanger such that the flow path passes through at least a portion of the heat exchanger between two sub-reactors along the flow path. At least one fuel injector is arranged relative to at least one sub-reactor. The fuel injector is configured to inject fuel into the flow path at at least one of upstream of and in the respective at least one sub-reactor to generate a fuel-air mixture. A fuel tank ullage supply line fluidly connects the flow path to the fuel tank to supply an inert gas to a ullage of the fuel tank.

Fuel tank inerting systems are provided. The systems include a fuel tank, an air source arranged to supply air into a reactive flow path, a catalytic reactor having a plurality of sub-reactors along the flow path, and a heat exchanger. The sub-reactors are arranged relative to the heat exchanger such that the flow path passes through at least a portion of the heat exchanger between two sub-reactors along the flow path. At least one fuel injector is arranged relative to at least one sub-reactor. The fuel injector is configured to inject fuel into the flow path at at least one of upstream of and in the respective at least one sub-reactor to generate a fuel-air mixture. A fuel tank ullage supply line fluidly connects the flow path to the fuel tank to supply an inert gas to a ullage of the fuel tank.

A system, and associated method, for reducing oxidation of a friction disk may include a braking assembly comprising the friction disk and a conduit coupled to the braking assembly, with the conduit being in selectable fluid providing communication with the braking assembly. That is, the conduit may be configured to deliver inert fluid to the braking assembly, thus reducing the concentration of oxygen in the vicinity of the friction disks and thus reducing/mitigating oxidation of the friction disks.

A system and method for providing inerting gas to a protected space is disclosed. The system includes an air separation module that includes an air inlet, a membrane with a permeability differential between oxygen and nitrogen, a nitrogen-enriched air outlet, and an oxygen-enriched air outlet. The system also includes an air flow path between an air source and the air separation module inlet, and an inerting gas flow path between the air separation module nitrogen-enriched air outlet and the protected space.

A system and method for providing inerting gas to a protected space is disclosed. The system includes an air separation module that includes an air inlet, a membrane with a permeability differential between oxygen and nitrogen, a nitrogen-enriched air outlet, and an oxygen-enriched air outlet. The system also includes an air flow path between an air source and the air separation module inlet, and an inerting gas flow path between the air separation module nitrogen-enriched air outlet and the protected space.

Certain aspects relate to a ground support cart for charging an electric aircraft. An exemplary ground support cart includes a frame, at least a wheel operatively coupled to the frame and configured to facilitate rolling translation of the ground support cart, a cart battery mounted to the frame and configured to provide a first electrical charging current, a conductor in electric communication with the at least a cart battery, a coolant source mounted to the frame and configured to provide a coolant flow, a hose in fluidic communication with the coolant source, and a controller configured to control the first electrical charging current within the conductor and the coolant flow within the hose.

Certain aspects relate to a ground support cart for charging an electric aircraft. An exemplary ground support cart includes a frame, at least a wheel operatively coupled to the frame and configured to facilitate rolling translation of the ground support cart, a cart battery mounted to the frame and configured to provide a first electrical charging current, a conductor in electric communication with the at least a cart battery, a coolant source mounted to the frame and configured to provide a coolant flow, a hose in fluidic communication with the coolant source, and a controller configured to control the first electrical charging current within the conductor and the coolant flow within the hose.