A propulsion system for an aircraft includes a gas turbine engine and a fuel tank, wherein the fuel includes at least a proportion of a sustainable aviation fuel—SAF—having a density between 90% and 98% of the density, ρ.sub.K, of kerosene and a calorific value between 101% and 105% the calorific value CV.sub.K, of kerosene. The engine includes a combustor; and a fuel pump arranged to supply a fuel thereto at an energy flow rate, C, the pump being arranged to output fuel at a volumetric flow rate, Q, the percentage of fuel passing through the pump not provided to the combustor being referred to as a spill percentage. The fuel include X % SAF, where X % is in the range from 5% to 100%, and has a density, ρ.sub.F, and a calorific value CV.sub.F. The propulsion system is arranged so: the fuel-change spill ratio, R.sub.s, of: $R_s=\frac{\mathrm{spill}\mathrm{percentage}\mathrm{at}\mathrm{cruise}\mathrm{using}\mathrm{kerosene}}{\mathrm{spill}\mathrm{percentage}\mathrm{at}\mathrm{cruise}\mathrm{using}\mathrm{the}\mathrm{fuel}\mathrm{with}X\%SAF}$ is equal to: $\frac{Q-\left(C/\left({\mathrm{CV}}_K\times {\rho }_K\right)\right)}{Q-(C/({\mathrm{CV}}_F\times {\rho }_{}}$

A fuel tank system is disclosed that includes a fuel tank and a first fluid flow path between a gas space in the fuel tank and outside of the fuel system. A gas separation membrane is disposed with a first side in communication with the first fluid flow path and a second side in communication with a second fluid flow path. A fluid control device is in communication with the second fluid flow path and is configured to provide fluid flow from the second fluid flow path to a liquid space in the fuel tank or to outside of the fuel system. A prime mover is disposed in communication with the second fluid flow path, and is configured to move fluid on the second fluid flow path from the second side of the separation membrane to the fuel tank liquid space or to outside of the fuel system.

This invention is a connecting device for earth grounding aircraft and aerospace equipment. The connector assembly has two parts, an upper and lower. The upper part of the connector provides a receptacle to secure an aerospace chassis ground wire. An internal magnet holds the upper part to the lower part. The lower part is secured in the ground and is flush with the surrounding surface. It is subterraneously connected to a ground rod. Upon disconnection and removal of the upper part, the lower part stays in place and provides a smooth and unencumbered surface.

Methods, apparatus, systems, and articles of manufacture are disclosed to house a vehicle, including a first container leg disposed on a first corner of a first container, a second container leg disposed on a second corner of the first container, a third container leg disposed on a third corner of the first container, a fourth container leg disposed on a fourth corner of the first container, at least one of the first, second, third, and fourth container legs each having an upper portion with a ramped receiving slot and a lower portion with a first ramped foot, and wherein the ramped receiving slot is to receive a protrusion associated with a second ramped foot of a second container different from the first container.

Methods, apparatus, systems, and articles of manufacture are disclosed to house a vehicle, including a first container leg disposed on a first corner of a first container, a second container leg disposed on a second corner of the first container, a third container leg disposed on a third corner of the first container, a fourth container leg disposed on a fourth corner of the first container, at least one of the first, second, third, and fourth container legs each having an upper portion with a ramped receiving slot and a lower portion with a first ramped foot, and wherein the ramped receiving slot is to receive a protrusion associated with a second ramped foot of a second container different from the first container.

The present disclosure relates to an improved pilot valve assembly for a hydrant pit valve. The pilot valve assembly includes a poppet that is movable between an open position and a closed position. The poppet has a molded seal with an interlock feature to hold the seal rigidly. The pilot valve assembly also includes a manually reset mechanism. The reset mechanism can be horizontally positioned and can function to reset the pilot actuator for the next refueling operation. A lanyard can be connected to the poppet to be used a deactuation mechanism.

A VTOL aircraft system includes a first unit having a cockpit, at least one propeller, at least two landing legs and at least two locking mechanisms. A second unit has a housing with a base portion, a first unit engaging portion, and at least two lock mechanism-engaging structure, each corresponding to one of the at least two locking mechanisms of the first unit. The housing of the second unit defines at least one interior cavity with at least one cargo area, a central passage providing access between the first and second unit, and a fuel cell configured around the central passage.

A receiver surge test tool (STT) assembly, system and method for receiver surge pressure testing. The receiver STT assembly has a receiver surge test tool (STT) configured to simulate surge pressure conditions of a receiver aircraft, and to measure one or more surge pressures generated when receiving a fuel flow of fuel from a refueling source during the receiver surge pressure testing that is ground based. The receiver STT has a pipe manifold structure with inlet port(s), outlet port(s), and one or more flow lines disposed therebetween. Each flow line includes a flow meter, a pressure transducer, a shutoff valve having varying valve close rates, and a manual back pressure valve. The receiver STT assembly has a control system for controlling open and close positions of the shutoff valve, and the receiver STT, and has a data system for collecting and recording data generated during the receiver surge pressure testing.

A receiver surge test tool (STT) assembly, system and method for receiver surge pressure testing. The receiver STT assembly has a receiver surge test tool (STT) configured to simulate surge pressure conditions of a receiver aircraft, and to measure one or more surge pressures generated when receiving a fuel flow of fuel from a refueling source during the receiver surge pressure testing that is ground based. The receiver STT has a pipe manifold structure with inlet port(s), outlet port(s), and one or more flow lines disposed therebetween. Each flow line includes a flow meter, a pressure transducer, a shutoff valve having varying valve close rates, and a manual back pressure valve. The receiver STT assembly has a control system for controlling open and close positions of the shutoff valve, and the receiver STT, and has a data system for collecting and recording data generated during the receiver surge pressure testing.

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.