A method is provided involving a turbine engine. During this method, data is received indicative of twist of a shaft of the turbine engine. The data is monitored over time to identity one or more reversal events while the turbine engine is operating, where each of the reversal events corresponds to a reversal in a value sign of the data. Shaft shear is identified in the shaft based on occurrence of N number of the reversal events.

The method can include: monitoring a current value of a rate of reduction of torque of the shaft; providing a threshold value for the rate of reduction of torque of the shaft; and generating a signal indicative of the shaft shear event when the current value exceeds the threshold value.

The method can include: monitoring a current value of a rate of reduction of torque of the shaft; providing a threshold value for the rate of reduction of torque of the shaft; and generating a signal indicative of the shaft shear event when the current value exceeds the threshold value.

The invention relates to a structural assembly for a gas turbine engine, which structural assembly comprises a fan and a forked fan shaft, which is coupled to the fan and comprises a radially outer fan shaft and a radially inner fan shaft being fixedly connected to the fan, and the predetermined breaking point being designed to break when a fan blade is lost. A contact mechanism is provided, which is activated by a decrease in the rotational speed of the fan shafts and which couples the radially inner fan shaft to the radially outer fan shaft when the rotational speed of the fan shafts falls below a predefined rotational speed after the predetermined breaking point has broken. After the fan shafts have been coupled by the contact mechanism, radially acting forces are transmitted from the radially inner fan shaft to the radially outer fan shaft.

A turbomachine includes a fan shaft driven by a turbine shaft via a device for reducing a speed of rotation. The turbomachine includes an uncoupling device interposed between the reduction device and the turbine shaft. The uncoupling device is configured to uncouple the reduction device and the turbine shaft in response to the exceeding of a determined resistant torque exerted by the reduction device on the turbine shaft.

A turbomachine includes a fan shaft driven by a turbine shaft via a device for reducing a speed of rotation. The turbomachine includes an uncoupling device interposed between the reduction device and the turbine shaft. The uncoupling device is configured to uncouple the reduction device and the turbine shaft in response to the exceeding of a determined resistant torque exerted by the reduction device on the turbine shaft.

The invention regards a gas turbine engine control system and a method for limiting turbine overspeed in case of a shaft failure. The control system includes: an overspeed protection system that activates an activation member in case a shaft failure is detected; a fuel limiting mechanism coupled with the activation member, wherein the fuel limiting mechanism is configured to limit the fuel supply to the gas turbine engine combustor if the activation member is activated; a variable stator vane mechanism which is configured to adjust variable stator vanes of a compressor of the gas turbine engine in their rotational position, the variable stator vanes having a closed position which blocks air flow through the compressor. A connecting fuel line connecting the fuel limiting mechanism and the variable stator vane mechanism is provided, wherein upon activation of the activation member the fuel limiting mechanism pressurizes the connecting fuel line, thereby activating the variable stator vane mechanism to move at least one row of the variable stator vanes into the closed position.

Systems and methods for removing heat are provided. For example, a system comprises a support apparatus and a cooling apparatus, including a suction device for forcing air through a gas turbine engine, disposed on the support apparatus, which is moveable with respect to the engine to position the cooling apparatus in contact with an engine exhaust. A nozzle in operative communication with the suction device may force air through the engine. Further, the support apparatus may comprise a lift device, an angle adjustment mechanism, and a nozzle support element disposed on a longitudinal slide rail for adjusting a height, an angle, and a longitudinal position of the nozzle. A method of removing heat from a gas turbine engine after shutdown comprises positioning a cooling apparatus adjacent an exhaust; sealing the cooling apparatus to the exhaust; and operating a suction device of the cooling apparatus to move air through the engine.

Methods and systems for operating a gas turbine engine having variable geometry mechanisms are described. The method comprises detecting a failure event associated with the gas turbine engine, identifying a location of the failure event, selecting an aerodynamic load modulation schedule for the variable geometry mechanisms of the gas turbine engine as a function of the location of the failure event, and applying the aerodynamic load modulation schedule as selected to the variable geometry mechanisms during the failure event.

A method and system for operating a gas turbine engine coupled to an aircraft propeller are described herein. The method comprises detecting a command for unfeathering the propeller, inhibiting shaft shear detection logic in response to detecting the command for unfeathering the propeller, detecting completion of the unfeathering of the propeller, and enabling the shaft shear detection logic in response to detecting the completion of the propeller unfeathering.