A method, system and apparatus are provided for reducing or eliminating contrails formed by an aircraft as it travels through the sky, and more particularly, to disrupting formation of contrails and altering the electromagnetic properties of already-formed contrails through use of one or more lasers. Methods include: positioning at least one laser such that at least one beam from the at least one laser is directed to a position at which contrails form aft of a wing of the aircraft; detecting contrail formation in the position at which contrails form aft of the wing of the aircraft; activating the at least one laser source in response to detecting contrail formation; and reducing or eliminating the contrail in response to activating the at least one laser source.

A method, system and apparatus are provided for reducing or eliminating contrails formed by an aircraft as it travels through the sky, and more particularly, to disrupting formation of contrails and altering the electromagnetic properties of already-formed contrails through use of one or more lasers. Methods include: positioning at least one laser such that at least one beam from the at least one laser is directed to a position at which contrails form aft of a wing of the aircraft; detecting contrail formation in the position at which contrails form aft of the wing of the aircraft; activating the at least one laser source in response to detecting contrail formation; and reducing or eliminating the contrail in response to activating the at least one laser source.

An aircraft includes a fuel cell-powered electric engine system configured to power the aircraft and produce water vapor exhaust, and an exhaust system configured to receive the water vapor exhaust, condense the water vapor into ice or water, and expel the ice or water from the aircraft such that water vapor cloud formation is inhibited. A method of powering an aircraft includes operating a fuel cell-powered electric engine system to power the aircraft, condensing water vapor exhaust of the fuel cell-powered electric engine system into ice or water, and expelling the ice or water from the aircraft such that water vapor cloud formation is inhibited.

An aircraft includes a fuel cell-powered electric engine system configured to power the aircraft and produce water vapor exhaust, and an exhaust system configured to receive the water vapor exhaust, condense the water vapor into ice or water, and expel the ice or water from the aircraft such that water vapor cloud formation is inhibited. A method of powering an aircraft includes operating a fuel cell-powered electric engine system to power the aircraft, condensing water vapor exhaust of the fuel cell-powered electric engine system into ice or water, and expelling the ice or water from the aircraft such that water vapor cloud formation is inhibited.

An aircraft may have one or more electrically powered thrust-generating engines and a combustion engine forming part of a power generator system for powering the electric engine and/or recharging a battery system that powers the electric engine. An exhaust pipe leads via an interior space within the aircraft from the exhaust of the combustion engine, or other source of hot gases, to an exhaust outlet. The direction of the exhaust pipe at the outlet is transverse to the longitudinal axis of the aircraft. A fairing immediately upstream of the outlet has a trailing edge, for example with a sawtooth profile, which creates turbulence and/or chaotic airflow over and downstream of the outlet, and thus mixes the freestream air and the hot gases from inside the aircraft more efficiently.

An aircraft may have one or more electrically powered thrust-generating engines and a combustion engine forming part of a power generator system for powering the electric engine and/or recharging a battery system that powers the electric engine. An exhaust pipe leads via an interior space within the aircraft from the exhaust of the combustion engine, or other source of hot gases, to an exhaust outlet. The direction of the exhaust pipe at the outlet is transverse to the longitudinal axis of the aircraft. A fairing immediately upstream of the outlet has a trailing edge, for example with a sawtooth profile, which creates turbulence and/or chaotic airflow over and downstream of the outlet, and thus mixes the freestream air and the hot gases from inside the aircraft more efficiently.

An aircraft comprises a machine body. The machine body encloses a turbofan gas turbine engine and a plurality of ancillary systems. The turbofan gas turbine engine comprises, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, a combustor module, a turbine module, and an exhaust module. The machine body comprises a single fluid inlet aperture, with the fluid inlet aperture being configured to allow a fluid cooling flow to enter the machine body and to pass through the heat exchanger module. The heat exchanger module is configured to transfer a waste heat load from the gas turbine engine and the ancillary systems to the fluid cooling flow prior to an entry of the entire fluid cooling flow into the fan module.

An aircraft comprises a machine body. The machine body encloses a turbofan gas turbine engine and a plurality of ancillary systems. The turbofan gas turbine engine comprises, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, a combustor module, a turbine module, and an exhaust module. The machine body comprises a single fluid inlet aperture, with the fluid inlet aperture being configured to allow a fluid cooling flow to enter the machine body and to pass through the heat exchanger module. The heat exchanger module is configured to transfer a waste heat load from the gas turbine engine and the ancillary systems to the fluid cooling flow prior to an entry of the entire fluid cooling flow into the fan module.

A propulsion system for an aircraft includes a rotor and a nacelle fairing that extends around the rotor in relation to an axis. The nacelle fairing includes an upstream portion forming an inlet section of the nacelle fairing as well as a downstream portion, a downstream end of which forms an outlet section of the nacelle fairing. The downstream portion includes radially inner and outer walls, both of which are made of a deformable shape memory material. The wall has independently actuatable piston actuator mechanisms, each actuator mechanism being actuatable independently of the others and being designed to cooperate with means built into an inner surface of the wall to deform the wall in a radial direction in relation to the axis under the effect of a predetermined displacement command.

An acoustic panel with a cellular core includes cells that are provided with one or more obstacles, each of the obstacles extending transversely in relation to the main axis of the associated cell so as to increase the length of the path (F) that sound waves travel through the cell. Methods enabling the production of such a panel implements steps of cutting, folding and bonding that are suitable for creating cells provided with such obstacles.