A use of a sheet material including a laminate of a first layer of a resilient polymer and a membrane outwardly of the first layer, the membrane being a polymer harder than the resilient polymer, for application to an exterior surface of an aircraft fuselage for noise reduction within the cabin. A method for mitigating vibroacoustic noise in a passenger cabin of an aircraft having a fuselage, the method comprising: coating a portion of an exterior surface of the fuselage with a resilient sheet material.

An aircraft with an in-boom lift propulsor includes a fuselage, a boom with a recess in the upper surface, and a lift propulsor comprising of a motor assembly and a propulsive element. Motor on the aircraft is operated through an interaction between the motor's magnetic field and electric current in a wire winding to generate force on a shaft of the motor. The in-boom lift propulsor helps prevent damages to the motor assembly and the aircraft by absorbing torque from the rotor and absorbing moment from the mating flange 328, where the mating flange 328 joins the motor assembly to the boom. The boom includes an access panel to service the motor assembly and invertor during maintenance.

An aircraft with an in-boom lift propulsor includes a fuselage, a boom with a recess in the upper surface, and a lift propulsor comprising of a motor assembly and a propulsive element. Motor on the aircraft is operated through an interaction between the motor's magnetic field and electric current in a wire winding to generate force on a shaft of the motor. The in-boom lift propulsor helps prevent damages to the motor assembly and the aircraft by absorbing torque from the rotor and absorbing moment from the mating flange 328, where the mating flange 328 joins the motor assembly to the boom. The boom includes an access panel to service the motor assembly and invertor during maintenance.

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.

A sound-absorbing panel includes: an inner skin traversed by holes and intended to be oriented towards a channel in which a fluid flows, a heating mat formed by strips fixed to the inner skin on the side opposite to the channel and oriented in a first direction, wherein two adjacent strips are distant from each other in order to define a slot between them, a base fixed to the strips on the side opposite to the inner skin, wherein the base includes, on the strips side, grooves extending in a second direction different from the first direction and wherein the base has, between two successive grooves, a rib, a cellular core fixed to the base on the side opposite to the strips, and an outer panel fixed to the cellular core on the side opposite to the base.

A sound-absorbing panel includes: an inner skin traversed by holes and intended to be oriented towards a channel in which a fluid flows, a heating mat formed by strips fixed to the inner skin on the side opposite to the channel and oriented in a first direction, wherein two adjacent strips are distant from each other in order to define a slot between them, a base fixed to the strips on the side opposite to the inner skin, wherein the base includes, on the strips side, grooves extending in a second direction different from the first direction and wherein the base has, between two successive grooves, a rib, a cellular core fixed to the base on the side opposite to the strips, and an outer panel fixed to the cellular core on the side opposite to the base.

An assembly is provided for an aircraft propulsion system. This assembly includes a nacelle inner structure that extends axially along and circumferentially about an axial centerline. The nacelle inner structure includes an internal compartment and a cowl. The internal compartment is configured to house a core of a gas turbine engine. The cowl is configured to form an outer radial periphery of the internal compartment. An aft end portion of the cowl is also configured to form an outer radial periphery of a compartment exhaust to the internal compartment. The aft end portion of the cowl includes a plurality of axial fingers arranged circumferentially about the axial centerline in an array.

An assembly is provided for an aircraft propulsion system. This assembly includes a nacelle inner structure that extends axially along and circumferentially about an axial centerline. The nacelle inner structure includes an internal compartment and a cowl. The internal compartment is configured to house a core of a gas turbine engine. The cowl is configured to form an outer radial periphery of the internal compartment. An aft end portion of the cowl is also configured to form an outer radial periphery of a compartment exhaust to the internal compartment. The aft end portion of the cowl includes a plurality of axial fingers arranged circumferentially about the axial centerline in an array.

A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a pre-cooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the pre-cooler into a core compartment.

A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a pre-cooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the pre-cooler into a core compartment.