An air starter for starting a turbine engine that includes a housing, a turbine member, a drive shaft, and at least one bearing assembly. The housing can define an interior where the turbine couples to the drive shaft that is rotatably supported by the least one bearing assembly. A lubricant passageway can provide lubrication to the at least one bearing assembly.

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 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.

A disclosed drive assembly for an auxiliary power unit includes a first drive shaft driven by an auxiliary power unit, a second drive shaft driven by a first electric motor, a differential gear system including a ring gear driven by the second drive shaft, a and planet gears supported within a carrier attached to the ring gear. The first drive shaft and an output shaft are coupled to the planet gears and a generator is driven by the output shaft. The electric motor and the auxiliary power unit combine to drive the output shaft.

An air turbine starter for starting an engine, comprising a housing having an interior surface defining an interior, at least one turbine member rotatably mounted within the interior about a rotational axis, and having a plurality of circumferentially spaced blades, and a containment structure radially overlying and circumferentially surrounding at least a portion of the at least one turbine member.

An air turbine starter for starting an engine, comprising a housing having an interior surface defining an interior, at least one turbine member rotatably mounted within the interior about a rotational axis, and having a plurality of circumferentially spaced blades, and a containment structure radially overlying and circumferentially surrounding at least a portion of the at least one turbine member.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.

An air starter for starting a turbine engine that includes a housing, a turbine, an output shaft, and at least one bearing. The housing can define an interior where the turbine couples to the output shaft. A primary air flow path extends through the housing where air from the turbine can be exhausted through a primary outlet or a cooling outlet.