Abstract: A gas turbine engine de-icing system includes a heat exchanger. A coolant loop is in fluid communication with the heat exchanger and is configured to circulate a heat transfer fluid. An engine oil loop is in fluid communication with the heat exchanger and is configured to transfer heat to the heat transfer fluid. A gas turbine engine inlet structure has at least one fan inlet guide vane. A spray bar is disposed at least partially in at least one fan inlet guide vane. The spray bar is in fluid communication with the coolant loop. The spray bar is configured to spray the heat transfer fluid onto an inner surface of the at least one fan inlet guide vane to de-ice the fan inlet guide vane.

Abstract: A gas turbine engine de-icing system includes a heat exchanger. A coolant loop is in fluid communication with the heat exchanger and is configured to circulate a heat transfer fluid. An engine oil loop is in fluid communication with the heat exchanger and is configured to transfer heat to the heat transfer fluid. A gas turbine engine inlet structure has at least one fan inlet guide vane. A spray bar is disposed at least partially in at least one fan inlet guide vane. The spray bar is in fluid communication with the coolant loop. The spray bar is configured to spray the heat transfer fluid onto an inner surface of the at least one fan inlet guide vane to de-ice the fan inlet guide vane.

Abstract: Disclosed is a flutter damper, including a chamber having an internal space, a movable diaphragm disposed at least partially within the chamber, the diaphragm separating the chamber into a first chamber and a second chamber, the second chamber forming an acoustic volume, wherein a size of the acoustic volume configures the chamber for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes, and a biasing member that moves the diaphragm responsive to a signal from an aircraft or engine electronic control (EEC) unit, wherein movement of the diaphragm increases or reduces the size of the acoustic volume of the second chamber.

Abstract: Disclosed is a flutter damper, including an acoustic liner having a perforated radial inner face sheet and a radial outer back sheet, the acoustic liner being configured for peak acoustical energy absorption at a frequency range that is greater than a frequency range associated with fan flutter, a chamber secured to the radial outer back sheet, the chamber being in fluid communication with the acoustic liner, and the chamber being configured for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes, and at least one stiffening structure connected to a top surface of the chamber that tunes the top surface out of the frequency range associated with one or more fan flutter modes.

Abstract: A gas turbine engine may include at least one of a fan inlet case and a bypass duct case. Additionally, the gas turbine engine may include a variable volume acoustic damper coupled to the at least one of the fan inlet case and the bypass duct case, wherein the variable volume acoustic damper is configured to damp acoustic energy. The variable volume acoustic damper may include a case and a diaphragm movably coupled within the case. An acoustic volume may be defined by a position of the diaphragm relative to the case and the acoustic volume may correspond to and may be configured to damp acoustic energy of a gas turbine engine.

Abstract: Disclosed is a flutter damper, including an acoustic liner having a perforated radial inner face sheet and a radial outer back sheet, the acoustic liner being configured for peak acoustical energy absorption at a frequency range that is greater than a frequency range associated with fan flutter, a chamber secured to the radial outer back sheet, the chamber being in fluid communication with the acoustic liner, and the chamber being configured for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes, and at least one stiffening structure connected to a top surface of the chamber that tunes the top surface out of the frequency range associated with one or more fan flutter modes.

Abstract: Disclosed is a flutter damper, including a chamber having an internal space, a movable diaphragm disposed at least partially within the chamber, the diaphragm separating the chamber into a first chamber and a second chamber, the second chamber forming an acoustic volume, wherein a size of the acoustic volume configures the chamber for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes, and a biasing member that moves the diaphragm responsive to a signal from an aircraft or engine electronic control (EEC) unit, wherein movement of the diaphragm increases or reduces the size of the acoustic volume of the second chamber.

Abstract: A gas turbine engine may include at least one of a fan inlet case and a bypass duct case. Additionally, the gas turbine engine may include a variable volume acoustic damper coupled to the at least one of the fan inlet case and the bypass duct case, wherein the variable volume acoustic damper is configured to damp acoustic energy. The variable volume acoustic damper may include a case and a diaphragm movably coupled within the case. An acoustic volume may be defined by a position of the diaphragm relative to the case and the acoustic volume may correspond to and may be configured to damp acoustic energy of a gas turbine engine.

Abstract: A gas turbine engine de-icing system includes a heat exchanger. A coolant loop is in fluid communication with the heat exchanger and is configured to circulate a coolant. An engine oil loop is in fluid communication with the heat exchanger and is configured to transfer heat to the coolant. A gas turbine engine inlet structure includes a cavity. A manifold is arranged in the cavity and is in fluid communication with the coolant loop. The manifold is configured to spray the coolant onto the gas turbine engine inlet structure to de-ice the gas turbine engine inlet structure.

Abstract: A nacelle assembly includes a thrust reverser moveable between a stowed position and a deployed position, a variable area fan nozzle, a motor to move the variable area fan nozzle, a drive shaft including a first portion coupled to the motor and a second portion coupled to the variable area fan nozzle, and a clutch mechanism that couples the first portion of the drive shaft and the second portion of the drive shaft The first portion of the drive shaft decouples from the second portion of the drive shaft when the thrust reverser moves from the stowed position to the deployed position.