A propulsion system for an aircraft, which has a chassis, a propeller able to move in rotation about an axis of rotation, a main gear as one with the propeller, an electric generator, at least one linear electric motor having a fixed element and a slider able to move in translation, for each linear electric motor, a secondary gear meshing with the main gear and mounted to be able to move in rotation about an axis of rotation perpendicular to the axis of rotation, and a rod of which one end is articulated on the corresponding slider and of which the other end is articulated on the corresponding secondary gear at an articulation that is offset with respect to the axis of rotation of the secondary gear.

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 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.

In the method for propelling an aircraft, to obtain electric energy, a fuel is combusted, and an electric machine is used, wherein the fuel is used to cool at least one part of the electric machine and contains natural gas. The propulsion system is configured to propel an aircraft, in particular according to the above-mentioned method. The propulsion system has an electric machine configured to obtain electric energy by combusting a fuel. The propulsion system further includes a natural gas tank configured to supply the fuel formed with natural gas, and a cooling device configured to cool at least one part of the electric machine. The aircraft has such a propulsion system.

In the method for propelling an aircraft, to obtain electric energy, a fuel is combusted, and an electric machine is used, wherein the fuel is used to cool at least one part of the electric machine and contains natural gas. The propulsion system is configured to propel an aircraft, in particular according to the above-mentioned method. The propulsion system has an electric machine configured to obtain electric energy by combusting a fuel. The propulsion system further includes a natural gas tank configured to supply the fuel formed with natural gas, and a cooling device configured to cool at least one part of the electric machine. The aircraft has such a propulsion system.

An aircraft, such as a rotorcraft, may have (an) area(s) designated to house (a) fuel cell(s) and (an) aircraft structure(s) that may translate, during a drop impact of the aircraft, into the area(s) designated to house the fuel cell(s). (A) shaped fuel cell(s) may be provided and deployed therein, in accordance with the present systems and methods. Each respective shaped fuel cell may define (a) respective through-void(s) defined through the respective shaped fuel cell, and/or (an) respective edge cavit(y)(ies) defined along an edge of the shaped fuel cell, wherein the respective through-void(s) and/or the respective edge cavit(y)(ies) correspond to the respective aircraft structure(s) that may translate, during the drop impact of the aircraft, into the area(s) of the aircraft designated to house the respective fuel cell(s) to receive and accommodate the respective structure(s) during the drop impact.

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.

An environmental control system (ECS) for an aircraft includes a primary heat exchanger, a compressor including an inlet fluidically connected to the primary heat exchanger, a turbine operatively connected to the compressor, and a cryogenic fluid heat exchanger fluidically connected to the primary heat exchanger.

Aircraft systems including a fuel tank containing a cryogenic fuel, an engine configured to consume the fuel, and an ECS having a precooler arranged to receive the fuel and air from the engine. The precooler includes a first heat exchanger configured to receive a first state of the fuel and output a second state of the fuel and a second heat exchanger configured to receive the second state fuel and output a third state fuel. The first state has a first density, the second state has a second density, and the third state has a third density, wherein the first density is greater than the second density, and the second density is greater than the third density. The engine air is directed through the second heat exchanger first and then through the first heat exchanger.

Aircraft systems including a fuel tank containing a cryogenic fuel, an engine configured to consume the fuel, and an ECS having a precooler arranged to receive the fuel and air from the engine. The precooler includes a first heat exchanger configured to receive a first state of the fuel and output a second state of the fuel and a second heat exchanger configured to receive the second state fuel and output a third state fuel. The first state has a first density, the second state has a second density, and the third state has a third density, wherein the first density is greater than the second density, and the second density is greater than the third density. The engine air is directed through the second heat exchanger first and then through the first heat exchanger.