A flexible fuel bladder assembly for an aircraft includes a flexible fuel bladder positioned at an airframe and having an opening to allow a flow of fuel into and/or out of the fuel bladder. A breakaway valve is operably connected to the fuel bladder at the opening to control a flow of fuel therethrough. A non-contacting or loose fitting reaction feature is affixed to the airframe and is interactive with the breakaway valve such that movement of the breakaway valve relative to the reaction feature results in breakage of a valve body of the breakaway valve and closure of the breakaway valve to prevent flow of fuel therethrough while also allowing for a second reaction mode to cause breakage of a valve body should the connecting hose be pulled relative to the breakaway valve.

The application provides an autonomous refueling vehicle for a hydrogen-electric aircraft, which includes two or more wings. The wings are provided with one or more removable electric propulsion pods. The autonomous refueling vehicle includes a hydrogen refueling module adapted to connect to the propulsion pods and to a hydrogen source. The autonomous refueling vehi-cle includes also includes a propulsion pod handling device, which is adapted to remove the propulsion pod from the wings and to position the propulsion pods on the hydrogen refueling module such that the propulsion pods are connected to the hy-drogen refueling module. The autonomous refueling vehicle is also adapted to autonomously move itself to the hydrogen source to allow the hydrogen refueling module to removably connect to the hydrogen source for refueling of the propulsion pods.

The application provides an autonomous refueling vehicle for a hydrogen-electric aircraft, which includes two or more wings. The wings are provided with one or more removable electric propulsion pods. The autonomous refueling vehicle includes a hydrogen refueling module adapted to connect to the propulsion pods and to a hydrogen source. The autonomous refueling vehi-cle includes also includes a propulsion pod handling device, which is adapted to remove the propulsion pod from the wings and to position the propulsion pods on the hydrogen refueling module such that the propulsion pods are connected to the hy-drogen refueling module. The autonomous refueling vehicle is also adapted to autonomously move itself to the hydrogen source to allow the hydrogen refueling module to removably connect to the hydrogen source for refueling of the propulsion pods.

Fuel systems, apparatus and associated methods for preventing or hindering unwanted fuel transfer between fuel tanks of aircraft are described. An exemplary apparatus comprises a conduit portion disposed inside a fuel tank for receiving fuel in the first fuel tank. The conduit portion includes an orifice through a wall of the conduit. The orifice permits venting an interior of the conduit portion to an interior of the fuel tank to prevent unwanted fuel transfer due to siphoning. A deflector is disposed and configured to deflect a stream of fuel discharged from the orifice during fuel transfer.

A system comprises a non-transitory machine readable storage medium storing instructions and a database identifying a plurality of assets and a state of each asset. The instructions configure a processor for receiving updates to a distributed electronic ledger managed by plural peer processors. Each update includes an event or change affecting one of the assets. The peer processors verify portions of the ledger describing each event or change. At least one of the updates has not yet been recorded in the ledger at a time of the receiving. The processor computes a state of each asset, based on the updates, receives a request for a state of one of the assets; and responds to the request, reflecting each event and change affecting that asset. The response is performed without waiting for the peer processors to verify an update that has not yet been recorded in the ledger.

A method for validating a capacitance measurement device including, sending a first drive signal from a capacitance measurement device to a capacitor emulator, modifying the first drive signal by an four quadrant analog multiplier, directing the modified signal across a capacitor to produce a return signal, sending the return signal to the capacitance measurement device to validate the capacitor, and validating the return signal against an expected return signal by the capacitance measurement device.

A fuel sample extractor (FSE) for an aircraft includes a sample chamber, a lid configured to seal the sample chamber, a pump in selective fluid communication with an upper portion of the sample chamber, and a straw in selective fluid communication with a lower portion of the sample chamber and a fuel tank.

A system and method for the transfer of cryogenic fluid fuel includes a nozzle positionable with respect to fuel tank inlet, e.g., of an unmanned aerial vehicle (UAV), a seal to seal the area where the nozzle and inlet are connected, a collapsible and expandable bellows providing an isolation volume where the fluid is transferred from the nozzle into the inlet; a vacuum is provided in the volume to avoid accumulation of fuel or other species in the volume.

A system and method for the transfer of cryogenic fluid fuel includes a nozzle positionable with respect to fuel tank inlet, e.g., of an unmanned aerial vehicle (UAV), a seal to seal the area where the nozzle and inlet are connected, a collapsible and expandable bellows providing an isolation volume where the fluid is transferred from the nozzle into the inlet; a vacuum is provided in the volume to avoid accumulation of fuel or other species in the volume.

A system comprises a non-transitory machine readable storage medium storing instructions and a database identifying a plurality of assets and a state of each asset. The instructions configure a processor for receiving updates to a distributed electronic ledger managed by plural peer processors. Each update includes an event or change affecting one of the assets. The peer processors verify portions of the ledger describing each event or change. At least one of the updates has not yet been recorded in the ledger at a time of the receiving. The processor computes a state of each asset, based on the updates, receives a request for a state of one of the assets; and responds to the request, reflecting each event and change affecting that asset. The response is performed without waiting for the peer processors to verify an update that has not yet been recorded in the ledger.