Abstract: A spool of a gas turbine engine includes an outer shaft assembly positioned at and configured to rotate about an engine central longitudinal axis. The outer shaft assembly is secured to one or more rotating components of the gas turbine engine. The outer shaft assembly includes a first shaft portion, and a second shaft portion. The first shaft portion axially overlaps the first shaft portion at a shaft joint. A centering feature dis positioned at the shaft joint and is configured to radially center the second shaft portion relative to the first shaft portion. A tie shaft is concentric with and located radially inboard of the outer shaft assembly. The tie shaft is configured to apply an axially compressive load on the outer shaft assembly.

Abstract: A flange assembly includes a primary flange and a secondary flange positioned adjacent the primary flange. The primary flange includes a primary flange body defining a primary bolt aperture. The secondary flange includes a secondary flange body defining a secondary bolt aperture. The flange assembly further includes a bolt. The bolt includes a bolt body extending between a head end and a distal end along a bolt axis. The bolt body includes an annular surface disposed about the bolt axis. The bolt body further includes an annular groove formed in the annular surface and disposed about the bolt axis. The bolt body is positioned within the primary bolt aperture and the secondary bolt aperture. The flange assembly further includes a clip attached to the bolt body within the annular groove. The clip is positioned between the between the primary flange and the secondary flange.

Abstract: A flange assembly includes a primary flange and a secondary flange positioned adjacent the primary flange. The primary flange includes a primary flange body defining a primary bolt aperture. The secondary flange includes a secondary flange body defining a secondary bolt aperture. The flange assembly further includes a bolt. The bolt includes a bolt body extending between a head end and a distal end along a bolt axis. The bolt body includes an annular surface disposed about the bolt axis. The bolt body further includes an annular groove formed in the annular surface and disposed about the bolt axis. The bolt body is positioned within the primary bolt aperture and the secondary bolt aperture. The flange assembly further includes a clip attached to the bolt body within the annular groove. The clip is positioned between the between the primary flange and the secondary flange.

Abstract: The coupling can have a female member configured to rotate around an axis, defining an axial recess, and having a plurality of connections circumferentially arranged along a radially inner face; a male member extending inside the axial recess concentrically to the female member and having a plurality of connections circumferentially arranged along a radially outer face; and a plurality of circumferentially arranged links, each link having an inner end engaged with a corresponding one of the male member connections, and an outer end engaged with a corresponding female member connection, the links being slanted off the radial orientation, with the inner end being circumferentially offset from the outer end, the links subjected to compression when transmitting torque between the female member and male member.

Abstract: The coupling can have a female member configured to rotate around an axis, defining an axial recess, and having a plurality of connections circumferentially arranged along a radially inner face; a male member extending inside the axial recess concentrically to the female member and having a plurality of connections circumferentially arranged along a radially outer face; and a plurality of circumferentially arranged links, each link having an inner end engaged with a corresponding one of the male member connections, and an outer end engaged with a corresponding female member connection, the links being slanted off the radial orientation, with the inner end being circumferentially offset from the outer end, the links subjected to compression when transmitting torque between the female member and male member.

Abstract: Systems and methods for limiting power of a gas turbine engine for an aircraft are described herein. A blade angle of a propeller blade of the engine and a commanded power for the engine are obtained. A thrust transition direction is determined. The commanded power is compared to a selected threshold based on the blade angle and the thrust transition direction. Power to the engine is limited when the commanded power exceeds the selected threshold.

Abstract: A system and computer-implemented method of determining an acceleration of an engine are provided. The system comprises a processor and a memory comprising instructions stored thereon which when executed by the processor cause the system to perform a method of determining an acceleration of an engine. The method comprises obtaining and storing zero-crossing timestamps in a buffer, determining angular displacement times of the shaft based on the timestamps, applying a conversion factor to the angular displacement times, determining an acceleration of a shaft based on the angular displacement, and causing a fuel flow to the engine to be adjusted as a function of the acceleration as determined. The zero-crossing timestamps correspond to an angular displacement of a shaft associated with the engine. The zero-crossing timestamps are obtained using an angular displacement measurement device. The conversion factor corresponds to an angular displacement of the shaft.

Abstract: Herein provided are methods and systems for detecting failure of a sensor in a control system for a gas turbine engine. A signal is received from the sensor. A high-pass filter is applied to the signal to produce a high-frequency component signal. A rate of occurrence of signal spikes in the high-frequency component signal is determined. The high-frequency component signal is compared to a component signal threshold which is based on at least one known healthy component signal and at least one faulty component signal. The presence of intermittent open circuits caused by the sensor is detected based on the comparing and on the rate of occurrence of signal spikes.

Abstract: Systems and methods for limiting power of a gas turbine engine for an aircraft are described herein. A blade angle of a propeller blade of the engine and a commanded power for the engine are obtained. A thrust transition direction is determined. The commanded power is compared to a selected threshold based on the blade angle and the thrust transition direction. Power to the engine is limited when the commanded power exceeds the selected threshold.

Abstract: Herein provided are methods and systems for detecting failure of a sensor in a control system for a gas turbine engine. A signal is received from the sensor. A high-pass filter is applied to the signal to produce a high-frequency component signal. A rate of occurrence of signal spikes in the high-frequency component signal is determined. The high-frequency component signal is compared to a component signal threshold which is based on at least one known healthy component signal and at least one faulty component signal. The presence of intermittent open circuits caused by the sensor is detected based on the comparing and on the rate of occurrence of signal spikes.

Abstract: Herein provided are methods and systems for detecting failure of a sensor in a control system for a gas turbine engine. A filtered signal is received from the sensor. A high-pass filter is applied to the filtered signal to produce a high-frequency component signal. A rate of occurrence of signal spikes in the high-frequency component signal is determined. The high-frequency component signal is compared to a component signal threshold based on at least one known healthy component signal and at least one faulty component signal, wherein the faulty component signal is based on a known faulty signal caused by intermittent open circuits. The presence of intermittent open circuits caused by the sensor is detected based on the comparing and on the rate of occurrence of signal spikes.