Abstract: A movable barrier operator comprising a motor, communication circuitry configured to receive a control signal and communicate with a door lock associated with a passageway door, and a controller. The controller is configured to authenticate the control signal, wherein authenticating the control signal includes associating the signal with a first level of access or a second level of access. The controller is further configured to communicate with the door lock via the communication circuitry to permit opening of the passageway door in response to associating the control signal with the first level of access and inhibit opening of the passageway door in response to associating the control signal with the second level of access. The controller is configured to cause the motor to open the movable barrier regardless of association of the control signal with the first level of access or the second level of access.

Abstract: A movable barrier operator comprising a motor, communication circuitry configured to receive a control signal and communicate with a door lock associated with a passageway door, and a controller. The controller is configured to authenticate the control signal, wherein authenticating the control signal includes associating the signal with a first level of access or a second level of access. The controller is further configured to communicate with the door lock via the communication circuitry to permit opening of the passageway door in response to associating the control signal with the first level of access and inhibit opening of the passageway door in response to associating the control signal with the second level of access. The controller is configured to cause the motor to open the movable barrier regardless of association of the control signal with the first level of access or the second level of access.

Abstract: A dual-film damper has a housing defining an annular damper fluidly connected to a source of pressurized oil. First and second damper rings are coaxially nested within the damper cavity. A first set of spacers allows for the formation of a first oil film annulus between the first and second damper rings. A second set of spacers allows for the formation of a second oil film annulus between the second damper ring and the housing. The first and second oil film annuli have a thickness-to-length ratio (T/L) selected to provide a desired damping capacity.

Abstract: A process for repairing an aircraft engine component includes receiving a plurality of component measurements of a damaged component, comparing the plurality of component measurements of the damaged component to a finite element model of an ideal component, generating a finite element model of the damaged component based at least partially on the comparison, determining a corrective material removal operation based at least in part on the finite element model of the damaged component, and removing material from the damaged component according to the corrective material removal operation, thereby creating a repaired component.

Abstract: A dual-film damper has a housing defining an annular damper fluidly connected to a source of pressurized oil. First and second damper rings are coaxially nested within the damper cavity. A first set of spacers allows for the formation of a first oil film annulus between the first and second damper rings. A second set of spacers allows for the formation of a second oil film annulus between the second damper ring and the housing. The first and second oil film annuli have a thickness-to-length ratio (T/L) selected to provide a desired damping capacity.

Abstract: A method of operation for a gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, reducing a rotational speed of a fan relative to a shaft through a gear train, driving the shaft with a low pressure turbine, driving a high pressure compressor with a high pressure turbine, communicating airflow from the fan through a bypass passage defined by a nacelle, the nacelle extending along an engine axis and surrounding the fan, discharging the airflow through a variable area fan nozzle defining a discharge airflow area, detecting an airfoil flutter condition associated with adjacent airfoils of the fan, and moving the variable area fan nozzle to vary the discharge airflow area and mitigate the airfoil flutter condition.

Abstract: A gas turbine engine includes a circumferential array of stator vanes that have first and second vanes with different vibrational frequencies than one another. The first vanes are arranged in circumferentially alternating relationship with the second vanes.

Abstract: A gas turbine engine includes a fan rotating with a fan shaft, a compressor and a turbine section. The turbine section includes a fan drive rotor driving the fan through the fan shaft. At least one bearing is between an inner static case and the fan shaft. The inner static case is cantilever mounted to static structure, and has a forward end spaced in a forward direction toward the fan rotor from a cantilever mount. A damping assembly is associated with the inner static case.

Abstract: A method of operation for a gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, reducing a rotational speed of a fan relative to a shaft through a gear train, driving the shaft with a low pressure turbine, driving a high pressure compressor with a high pressure turbine, communicating airflow from the fan through a bypass passage defined by a nacelle, the nacelle extending along an engine axis and surrounding the fan, discharging the airflow through a variable area fan nozzle defining a discharge airflow area, detecting an airfoil flutter condition associated with adjacent airfoils of the fan, and moving the variable area fan nozzle to vary the discharge airflow area and mitigate the airfoil flutter condition.

Abstract: An anti-ice arrangement for a gas turbine engine may comprise an engine static structure, a fan blade housed for rotation within the engine static structure, and a magnetic field source mounted in close proximity to the fan blade and configured for inducing eddy currents in the fan blade to increase a surface temperature of the fan blade.

Abstract: A rotor assembly for a gas turbine engine includes a rotor defining an outer periphery; and a plurality of blades attached to the outer periphery. The plurality of blades includes a material property different than the other of the plurality of blades to provide mistuning of the rotor.

Abstract: A gas turbine engine includes a fan section that has a fan. A fan casing surrounds the fan section. A compressor section defines an engine axis. A gear train reduces a rotational speed of the fan relative to a shaft. A low pressure turbine is coupled to the shaft. A nacelle extends along the engine axis and surrounds the fan casing, a bypass ratio of greater than 10. A variable area fan nozzle defines a discharge airflow area. A flutter sensing system includes a controller programmed to move the variable area fan nozzle to vary the discharge airflow area in response to detecting an airfoil flutter condition associated with adjacent airfoils of the fan.

Abstract: A method of operation for a gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, reducing a rotational speed of a fan relative to a shaft through a gear train, driving the shaft with a first turbine, driving a compressor with a second turbine, communicating airflow from the fan through a bypass passage defined by a nacelle, the nacelle extending along an engine axis and surrounding the fan, and having a bypass ratio of greater than 10, discharging the airflow through a variable area fan nozzle defining a discharge airflow area, detecting an airfoil flutter condition associated with adjacent airfoils of the fan, and moving the variable area fan nozzle to vary the discharge airflow area and mitigate the airfoil flutter condition.

Abstract: A process for repairing an aircraft engine component includes receiving a plurality of component measurements of a damaged component, comparing the plurality of component measurements of the damaged component to a finite element model of an ideal component, generating a finite element model of the damaged component based at least partially on the comparison, determining a corrective material removal operation based at least in part on the finite element model of the damaged component, and removing material from the damaged component according to the corrective material removal operation, thereby creating a repaired component.

Abstract: A gas turbine engine includes a fan rotating with a fan shaft, a compressor and a turbine section. The turbine section includes a fan drive rotor driving the fan through the fan shaft. At least one bearing is between an inner static case and the fan shaft. The inner static case is cantilever mounted to static structure, and has a forward end spaced in a forward direction toward the fan rotor from a cantilever mount. A damping assembly is associated with the inner static case.

Abstract: An anti-ice arrangement for a gas turbine engine may comprise an engine static structure, a fan blade housed for rotation within the engine static structure, and a magnetic field source mounted in close proximity to the fan blade and configured for inducing eddy currents in the fan blade to increase a surface temperature of the fan blade.

Abstract: A gas turbine engine includes a fan section that has a fan with a plurality of airfoils, a compressor section, a gear train that reduces a rotational speed of the fan relative to a shaft in operation, a turbine section that has a first turbine and a second turbine, and a bypass ratio of greater than 10. The first turbine drives the shaft. A nacelle extends along an engine axis and surrounds the fan. A variable area fan nozzle defines a discharge airflow area. A fan airfoil flutter sensing system has a first sensor that actively and selectively detects a fan airfoil flutter condition in operation, and communicates with a controller programmed to move the variable area fan nozzle and vary the discharge airflow area to mitigate the flutter condition.

Abstract: A bearing assembly for an engine is disclosed. The bearing assembly includes a first structure, a second structure that is movable relative to the first structure, and a foil membrane disposed between the first structure and the second structure. The foil membrane includes at least one perforation that supplies liquid fuel in a region between the foil membrane and the second structure, where the liquid fuel is combusted by the engine.

Abstract: A hollow blade of a gas turbine engine has a sacrificial elongated damper disposed slideably in a chamber for minimizing modes of vibration during operation. The chamber is defined between two opposing surfaces generally spanning radially outward from an axis of the engine and a face facing radially inward. The damper is constructed and arranged to make loaded contact with the face via a centrifugal force created by rotation of the engine.

Abstract: A bearing assembly is provided. The bearing assembly includes an inner race configured to couple to a shaft, an outer race disposed around the inner race, and a housing disposed around the outer race. The housing and the outer race define an annulus and a buffer region, and the buffer region defines an axial boundary of the annulus.