A gas turbine engine comprises a fan drive turbine, a fan rotor, and a gear reduction driven by the fan drive turbine to, in turn, drive the gear architecture. A main oil supply system supplies oil to components within the gear reduction, and an auxiliary oil supply system. The auxiliary oil system operates to ensure that the gear reduction will be adequately supplied with lubricant for at least 30 seconds at power should the main oil supply system fail.

Embodiments are directed to systems and methods for controlling an aircraft engine inlet comprises determining a required engine RPM for an engine in-flight restart based upon current aircraft parameters, detecting a command to initiate the engine in-flight restart, and managing a position of an engine inlet barrier to control a volume of air entering an engine intake, wherein the ram air causes an engine turbine to achieve the required engine RPM. The required engine RPM may be an N1 gas generator RPM. The engine inlet barrier may be a hinged door positioned within the engine inlet or a series of inlet variable guide vanes that are configured to rotate between a closed position and an opened position. The position of the engine inlet barrier may be controlled by a flight control computer or an engine control computer.

A shaft event is detected, such as a shaft shear, a shaft decoupling, and/or a shaft failure in a gas turbine engine comprising a first spool and a second spool different from the first spool. First and second parameters indicative of the power of the first spool and a load transfer through a shaft of the second spool are obtained. A detection threshold is determined as a function of the first parameter. The second parameter is compared to the detection threshold. The shaft event is detected when the second parameter is beyond the detection threshold and then a signal indicative of the shaft event is transmitted.

A rocket motor has an energetic material between solid fuel (propellent) and a casing that surrounds the solid fuel. The energetic material is configured to be burned along with the solid fuel during normal operation of the rocket motor to produce thrust. The energetic material can also be detonated to cause rupture of the casing. The detonation may be initiated as part of a flight termination process. The detonation may also be initiated as a part of process to prevent as a higher-order reaction, such as in reaction to heating from a fire or other cause. The energetic material may be arranged to function as part of a shaped charge, able to split the casing when detonated. By being located inside the casing, the energetic material does not adversely affect aerodynamics of the flight vehicle of which the rocket motor is a part, such as a missile.

A closing system that includes a closing actuator for doors of a thrust reverser, two sliding members, and a detection device. The closing actuator includes two first connecting rods. Each first connecting rod is configured to be connected to a first lateral edge of each door. The closing actuator is arranged to move each door at least towards the direct jet position. Each sliding member carries a second connecting rod configured to be connected to a second lateral edge of each door. The second connecting rods are arranged to be driven by the doors when the closing actuator moves the doors towards the direct jet position so as to displace the two sliding members. The detection device detects a defect of one of the first and second connecting rods. The detection device is configured to detect the relative position of the two sliding members in the direct jet position.

A closing system that includes a closing actuator for doors of a thrust reverser, two sliding members, and a detection device. The closing actuator includes two first connecting rods. Each first connecting rod is configured to be connected to a first lateral edge of each door. The closing actuator is arranged to move each door at least towards the direct jet position. Each sliding member carries a second connecting rod configured to be connected to a second lateral edge of each door. The second connecting rods are arranged to be driven by the doors when the closing actuator moves the doors towards the direct jet position so as to displace the two sliding members. The detection device detects a defect of one of the first and second connecting rods. The detection device is configured to detect the relative position of the two sliding members in the direct jet position.

An assembly for a turbine engine turbine includes a turbine rotor disc centered on a longitudinal axis and a turbine shaft centered on the longitudinal axis and driven in rotation by the rotor disc. Torque from the rotor disc is transmitted to the shaft, wherein the rotor disc is locked in translation relative to the shaft in the direction of the longitudinal axis by a screwed member on the shaft. Torque from the rotor disc is transmitted from the rotor disc to the screwed member when the torque ceases being transmitted from the rotor disc to the shaft. The screwed member has an unscrewing direction identical to the direction of rotation of the rotor disc in operation.

A shaft apparatus for a gas turbine engine comprising: a first shaft portion; a second shaft portion; and a ratchet mechanism configured to permit the first shaft portion to rotate with respect to the second shaft portion in a first direction, and to prevent the first shaft portion from rotating with respect to the second shaft portion in a second direction opposite to the first direction. A gas turbine engines comprising the shaft apparatus and methods of operating a gas turbine engine are also disclosed.

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.

Methods and systems for detecting a shaft event of a gas turbine engine are described. The method comprises monitoring at least one engine parameter and comparing the at least one engine parameter to a schedule for the at least one parameter defining a first threshold and a second threshold greater than the first threshold; applying a limit to the at least one engine parameter when the at least one engine parameter is inside a parameter limiting region between the first threshold and the second threshold, the first threshold separating the parameter limiting region from a normal operating region, the second threshold separating the parameter limiting region from a hazardous operating region; and detecting the shaft event when the at least one engine parameter crosses the second threshold and issuing a signal in response to the detecting.