A system includes a fuel level sensing probe inside a fuel tank and an exciter wire bundle to connect the fuel level sensing probe to a power source outside the tank. The exciter wire bundle includes an excitation wire and a grounded guard wire. The excitation wire and the grounded guard wire each include a resistive non-metallic wire. The system also includes a return signal wire bundle to connect the fuel level sensing probe to a device configured to measure a quantity of fuel within the tank. The return signal wire bundle includes a return signal wire and a grounded guard wire. The grounded guard wire of the return signal wire bundle and the grounded guard wire of the exciter wire bundle are configured to shield the return signal wire from electromagnetic interference. The return signal wire and the grounded guard wire each include a resistive non-metallic wire.

A method of delivering fuel to an engine during operation of the engine, that includes, sensing the speed of sound in the fuel, determining a density or property of the fuel, and based on that density or fuel property adjusting the flow rate of the fuel. Further, an established fuel profile or determined energy density value can also be used to adjust the flow rate of the fuel.

Herein provided are methods and systems for assessing a fuel burn level of an aircraft for a planned mission. Flight information relating to the planned mission is obtained via a graphical user interface, the flight information comprising configurable number of passengers for the aircraft. A requisite engine bleed level for the planned mission is determined based on the flight information. The fuel burn level is assessed based on the requisite engine bleed level.

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.

A pipeline including at least first and second portions, each comprising outer and inner pipes, at least one coupling system connecting the first and second portions and including at least a downstream flange ring connected to at least one of the outer and inner pipes of the first portion, at least an upstream flange ring connected to at least one of the outer and inner pipes of the second portion, connecting elements connecting the upstream and downstream flange rings, first and second annular seals interposed between the upstream and downstream flange rings and configured to delimit, with the upstream and downstream flange rings, a buffer space containing an atmosphere, the pipeline comprising at least one leak detection system configured to determine at least one characteristic of the atmosphere of the buffer space.

In accordance with at least one aspect of this disclosure, a fuel seal for an aircraft fuel system includes a seal ring of a metallic material configured to retain a shape of the seal ring under compression, and a coating of elastomeric material, over molded onto the seal ring and configured to conform to a shape of a sealing surface. In embodiments, the seal ring and coating can be configured to provide drop-tight sealing at a temperature of at least 400 degrees F. In certain embodiments, the seal ring and coating can be configured to seal one or more fuel system components of an aircraft fuel system.

Provided is a flight vehicle which makes it possible to more reliably retain the sealability of a sealing member of a valve provided on a hydrogen tank even in continuous supply of hydrogen or a low-temperature environment. The flight vehicle having a fuel cell, and a hydrogen tank in which hydrogen for generation of electricity by the fuel cell is stored includes: a valve including a sealing member, the valve being disposed on the hydrogen tank, via the valve hydrogen being taken out from a body of the tank; and a warming unit in which fluid conducts part of waste heat from any portion of the flight vehicle to the sealing member.

Method of adjusting the pressure balance or a control device, in particular of a servo valve, the requisite adjusting movement being applied by a disc translator.