In accordance with at least one aspect of this disclosure, there is provided a drive shaft system. In embodiments, the drive shaft system includes a generator shaft extending along a longitudinal axis with a longitudinal bore defined through the generator shaft. A thru shaft extends through the longitudinal bore of the generator shaft. In embodiments, the thru shaft includes, a front coupler mount at a first end operative to receive torque input, and a rear coupler mount at a second end opposite the first end.

A propeller blade arrangement comprising a propeller blade attached to and rotatable with a hub, via a retention bearing, the blade being rotatable about a center line of the blade, the retention bearing configured to tilt the blade such that its center line is tilted with respect to the hub.

A propeller blade arrangement comprising a propeller blade attached to and rotatable with a hub, via a retention bearing, the blade being rotatable about a center line of the blade, the retention bearing configured to tilt the blade such that its center line is tilted with respect to the hub.

The present disclosure relates to an impeller and a method of manufacturing the same. The impeller includes: a hub in which a plurality of spiral first slots are formed; a shroud which is positioned opposite the hub, and has a plurality of spiral second slots formed therein; and a plurality of blades which is coupled to the hub and the shroud, and have an upper protrusion formed on one side and a lower protrusion formed on the other side; and wherein the upper protrusion is inserted into and coupled to a second hole formed in the second slot, and the lower protrusion is inserted into and coupled to a first hole formed in the first slot.

The present disclosure relates to an impeller and a method of manufacturing the same. The impeller includes: a hub in which a plurality of spiral first slots are formed; a shroud which is positioned opposite the hub, and has a plurality of spiral second slots formed therein; and a plurality of blades which is coupled to the hub and the shroud, and have an upper protrusion formed on one side and a lower protrusion formed on the other side; and wherein the upper protrusion is inserted into and coupled to a second hole formed in the second slot, and the lower protrusion is inserted into and coupled to a first hole formed in the first slot.

A gas turbine engine includes a nacelle, and a bypass flow path in a bypass duct within the nacelle of the turbofan engine. A fan section includes a fan with fan blades. The fan section drives air along the bypass flow path. A fan shaft drives a fan that has fan blades and the fan rotates about a central longitudinal axis of the turbofan engine. A speed reduction device includes an epicyclic gear system. A turbine section is connected to the fan section through the speed reduction device and the turbine section rotates about the central longitudinal axis. A first fan bearing for supporting rotation of the fan hub is located axially forward of the speed reduction device. A second fan bearing for supporting rotation of the fan hub is located axially aft of the speed reduction device. A first outer race of the first fan bearing is fixed relative to the fan hub.

A gas turbine engine includes a nacelle, and a bypass flow path in a bypass duct within the nacelle of the turbofan engine. A fan section includes a fan with fan blades. The fan section drives air along the bypass flow path. A fan shaft drives a fan that has fan blades and the fan rotates about a central longitudinal axis of the turbofan engine. A speed reduction device includes an epicyclic gear system. A turbine section is connected to the fan section through the speed reduction device and the turbine section rotates about the central longitudinal axis. A first fan bearing for supporting rotation of the fan hub is located axially forward of the speed reduction device. A second fan bearing for supporting rotation of the fan hub is located axially aft of the speed reduction device. A first outer race of the first fan bearing is fixed relative to the fan hub.

System for selectively contacting a cleaning composition with a surface of a turbine engine component is presented. The system includes a cleaning apparatus and a manifold assembly. The cleaning apparatus includes an upper portion and a lower portion defining a cleaning chamber configured to allow selective contact between the cleaning composition and a surface of the first portion of the turbine engine component. The upper portion includes a plurality of fill holes in fluid communication with the cleaning chamber, and the lower portion includes a plurality of drain holes in fluid communication with the cleaning chamber. The manifold assembly is configured to selectively circulate the cleaning composition from a reservoir to the cleaning chamber via the plurality of fill holes, and recirculate the cleaning composition from the cleaning chamber to the reservoir via the plurality of drain holes. Methods for selectively cleaning a turbine engine component is also presented.

System for selectively contacting a cleaning composition with a surface of a turbine engine component is presented. The system includes a cleaning apparatus and a manifold assembly. The cleaning apparatus includes an upper portion and a lower portion defining a cleaning chamber configured to allow selective contact between the cleaning composition and a surface of the first portion of the turbine engine component. The upper portion includes a plurality of fill holes in fluid communication with the cleaning chamber, and the lower portion includes a plurality of drain holes in fluid communication with the cleaning chamber. The manifold assembly is configured to selectively circulate the cleaning composition from a reservoir to the cleaning chamber via the plurality of fill holes, and recirculate the cleaning composition from the cleaning chamber to the reservoir via the plurality of drain holes. Methods for selectively cleaning a turbine engine component is also presented.

A method of wire electric discharge machining (wEDM) a feature in a part includes using wEDM, cutting and detaching a slug from a portion of the part that is to be detached from the part to define the feature, and thereby defining a validation cut-out in the portion, and using wEDM, cutting and detaching the portion having the validation cut-out from the part and thereby defining the feature.