According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

According to an aspect, a system for a gas turbine engine includes a reduction gear train operable to drive rotation of a starter gear train that interfaces to an accessory gearbox of the gas turbine engine. The reduction gear train includes a starter interface gear that engages the starter gear train and a core-turning clutch operably connected to the starter interface gear. The reduction gear train also includes a geared rotary actuator including a primary planetary gear system, where the geared rotary actuator is operably connected to the core-turning clutch. The reduction gear train further includes a secondary planetary gear system operably connected to the primary planetary gear system and a core-turning input. The system also includes a mounting pad with an interface to couple a core-turning motor to the core-turning input of the reduction gear train.

According to an aspect, a system for a gas turbine engine includes a reduction gear train operable to drive rotation of a starter gear train that interfaces to an accessory gearbox of the gas turbine engine. The reduction gear train includes a starter interface gear that engages the starter gear train, a core-turning clutch operably connected to the starter interface gear, and a plurality of stacked planetary gear systems operably connected to the core-turning clutch and a core-turning input. The system also includes a mounting pad including an interface to couple a core-turning motor to the core-turning input of the reduction gear train.

An air starter for an engine, such as a turbine engine, that includes a turbine for rotatably extracting mechanical power from a flow of fluid. The turbine includes a drive shaft that can be coupled to an output shaft to provide a rotational output. The interface between the drive shaft and the output shaft can be offset and include piloted portions.

An engine control system may be configured to perform a method of controlling thermal bias in a turbomachine. An exemplary method may include determining a thermal bias-value for the turbomachine, and performing a cooling treatment based at least in part on the thermal bias-value. The thermal bias-value may include a difference between an upward temperature-value corresponding to a first one or more temperature measurements of an upward portion of the turbomachine and a downward temperature-value corresponding to a second one or more temperature measurements of a downward portion of the turbomachine. The cooling treatment may include at least one of: circulating air through at least a portion of the turbomachine, and rotating a shaft of the turbomachine with a motoring system.

A cabin blower for an aircraft, the system comprising: a cabin blower compressor; an electric machine; and a controller configured to control the cabin blower system so that: in a cabin blower mode of operation, the cabin blower compressor is driven by power extracted from one or more spools of a gas turbine engine of the aircraft and provides a flow of air to a cabin of the aircraft. The controller may be further configured to control the system so that: in a rotor bow mitigation mode of operation, the cabin blower compressor is driven by the electric machine using electrical power from an electrical power source and provides a flow of air through a core of the gas turbine engine to remove heat from the core. A method of operating a cabin blower system of an aircraft is also provided.

There is provided a dynamic motoring system and method for an aircraft engine. Motoring of the engine is initiated for an initial motoring duration and at an initial motoring interval. At least one engine parameter is measured in real-time during the motoring, the at least one engine parameter comprising a temperature of the engine. The initial motoring duration and the initial motoring interval are modified in real-time, based on a value of the at least one engine parameter during the motoring, to obtain a modified motoring duration and a modified motoring interval. The motoring continues for the modified motoring duration and at the modified motoring interval, with a speed of rotation of the engine being controlled using the modified motoring interval.

There is provided a dynamic motoring system and method for an aircraft engine. Motoring of the engine is initiated for an initial motoring duration and at an initial motoring interval. At least one engine parameter is measured in real-time during the motoring, the at least one engine parameter comprising a temperature of the engine. The initial motoring duration and the initial motoring interval are modified in real-time, based on a value of the at least one engine parameter during the motoring, to obtain a modified motoring duration and a modified motoring interval. The motoring continues for the modified motoring duration and at the modified motoring interval, with a speed of rotation of the engine being controlled using the modified motoring interval.

A maintenance system for a turbine engine includes a pump and a crank device operatively coupled to the pump. The pump includes a pump housing and a pump drive that is configured to operatively couple to the turbine engine. The crank device is operatively coupled to the pump and includes a crank drive that is configured to enable movement of the pump drive and thereby movement of the turbine engine during non-operational periods, such as during a maintenance or inspection period.

A maintenance system for a turbine engine includes a pump and a crank device operatively coupled to the pump. The pump includes a pump housing and a pump drive that is configured to operatively couple to the turbine engine. The crank device is operatively coupled to the pump and includes a crank drive that is configured to enable movement of the pump drive and thereby movement of the turbine engine during non-operational periods, such as during a maintenance or inspection period.