In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

A ducted fan unmanned aerial vehicle (UAV) docking station is provided. The docking station comprises: a guide sized to receive a ducted fan UAV; and a housing communicatively coupled to the guide. The housing comprises: a storage assembly comprising: at least one compartment sized to store the UAV; and at least one dampening system coupled to the at least one storage compartment for cushioning the UAV.

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.

A propulsion system includes at least one compressor, multiple conduits, a multiple-way valve, and at least one thrust augmentation device. A series of flaps can be retracted, tilted and operated in conjunction with the at least one thrust augmentation device. A converging channel in fluid communication with the valve is configured to allow expansion to ambient of a compressed air stream in a preferred single direction. The at least one thrust augmentation device each contains a mixing section, a throat section and a diffusor. Each said augmentation device receives compressed air from the at least one compressor via at least one of the conduits and valve and uses pressurized air as motive gas to generate thrust by fluidically entraining ambient air, mixing it with the motive gas and ejecting the motive gas at high velocities via the diffusor.

An exemplary aircraft includes a turbine engine having a gas generator spool and a power spool, the power spool operational to drive a rotor, a first generator coupled to the gas generator spool, and a controller operable to increase a load on the gas generator spool when the gas generator spool is on a speed limit thereby increasing a speed limit margin in order to increase power available from the turbine engine.

An exemplary aircraft includes a turbine engine having a gas generator spool and a power spool, the power spool operational to drive a rotor, a first generator coupled to the gas generator spool, and a controller operable to increase a load on the gas generator spool when the gas generator spool is on a speed limit thereby increasing a speed limit margin in order to increase power available from the turbine engine.

A touchscreen fuel panel. In embodiments, the fuel panel includes a touchscreen display and a controller coupled to the touchscreen display. The controller is configured to generate a graphical user interface at the touchscreen display and receive user inputs via the touchscreen display. In embodiments, the graphical user interface includes a pump menu, valve control icons, pump status indications, fuel quantity indications, and fuel calculations. The controller may be configured to present requested information and/or generate a control signal for at least one fuel system component in response to receiving a user input representing a user interaction with the graphical user interface.

A touchscreen fuel panel. In embodiments, the fuel panel includes a touchscreen display and a controller coupled to the touchscreen display. The controller is configured to generate a graphical user interface at the touchscreen display and receive user inputs via the touchscreen display. In embodiments, the graphical user interface includes a pump menu, valve control icons, pump status indications, fuel quantity indications, and fuel calculations. The controller may be configured to present requested information and/or generate a control signal for at least one fuel system component in response to receiving a user input representing a user interaction with the graphical user interface.

A method of determining one or more fuel characteristics of an aviation fuel for powering a gas turbine engine of an aircraft includes: measuring one or more trace substance parameters of the fuel, the one or more trace substance parameters each associated with a respective trace substance in the fuel; and determining one or more fuel characteristics of the fuel based on the one or more trace substance parameters. Further, a fuel characteristic determination system, a method of operating an aircraft, and an aircraft.

A vacuum system for use with a deoxygenator system includes a housing, a movable assembly positioned within the housing, and a biasing mechanism coupling the movable assembly to the housing. The movable assembly is movable between a first position and a second position within the housing to form a low pressure area between the housing and the movable assembly. A control system including at least one pressure source is arranged in fluid communication with the low pressure area. The control system is operable to selectively communicate fluid from the at least one pressure source to the housing to form the low pressure area.