Abstract: One example of a tiltrotor aircraft includes a rotor system, a pylon coupled to the rotor system, a spindle coupled to the pylon, an actuator arm coupled to the spindle, and an actuator. The actuator can cause the actuator arm to rotate, thereby causing the spindle to rotate the pylon and the rotor system. In an example, the actuator is in front of a forward spar of the wing of the tiltrotor aircraft and the actuator arm is about one-half (0.5) of an inch to about five (5) inches from the wing.

Abstract: An inlet barrier filter system for a tiltrotor aircraft comprising a filter duct extending from a filter to a filter outlet, a ram air duct extending from a ram air inlet to an engine where the filter duct connects to the ram air duct at the filter outlet, and a closure member movable between a first position blocking the ram air duct and a second position blocking the filter outlet. In use, the inlet barrier filter system provides for two mutually exclusive air flow paths, one for introducing ram air to the engine while closing off the filter and another air flow path for introducing filtered air to the engine while closing off the ram air duct.

Abstract: A torque box rib includes an upper rib cap configured to be coupled to an upper skin of a wing, a lower rib cap configured to be coupled to a lower skin of the wing, a forward post configured to be coupled to a forward spar of the wing, an aft post configured to be coupled to an aft spar of the wing, and a rib web configured to be coupled to the upper rib cap, the lower rib cap, the forward post, and the aft post.

Abstract: A propulsion and lift system of a tiltrotor aircraft includes a wing having an outboard end, a wing tip assembly having an inboard end, a fixed nacelle coupled to the wing tip assembly and a wing-nacelle splice assembly having inboard and outboard sides. The inboard side of the wing-nacelle splice assembly is coupled to the outboard end of the wing, and the outboard side of the wing-nacelle splice assembly is coupled to the inboard end of the wing tip assembly, thereby coupling the fixed nacelle to the wing.

Abstract: A pedestal assembly receives a pylon assembly of a tiltrotor aircraft having an airframe including a fuselage and a wing. The pedestal assembly includes inboard and outboard tip ribs that extend above the wing and respectively define inboard and outboard slots. The pedestal assembly also includes inboard and outboard bearing cartridges. The inboard bearing cartridge is received within the inboard slot, is coupled to the inboard tip rib and includes an inboard bearing assembly. The outboard bearing cartridge is received within the outboard slot, is coupled to the outboard tip rib and includes an outboard bearing assembly. The inboard and outboard bearing assemblies are operable to receive the pylon assembly therein such that the pylon assembly is rotatably mounted between the inboard and outboard tip ribs to selectively operate the tiltrotor aircraft between a helicopter mode and an airplane mode.

Abstract: A pedestal assembly for receiving a pylon assembly of a tiltrotor aircraft having a helicopter mode and an airplane mode, the tiltrotor aircraft having an airframe including a fuselage and a wing. The pedestal assembly includes an inboard pedestal supported by the airframe and positioned above the wing. The inboard pedestal includes an inboard bearing assembly disposed within an inboard pillow block housing. The pedestal assembly also includes an outboard pedestal supported by the airframe and positioned above the wing. The outboard pedestal includes an outboard bearing assembly disposed within an outboard pillow block housing. The inboard and outboard bearing assemblies are operable to receive the pylon assembly therein such that the pylon assembly is rotatably mounted between the inboard and outboard pedestals to selectively operate the tiltrotor aircraft between the helicopter mode and the airplane mode.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to an input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a spherical bearing providing a self-aligning coupling with the pylon assembly.

Abstract: A pedestal assembly for receiving a pylon assembly of a tiltrotor aircraft having a helicopter mode and an airplane mode, the tiltrotor aircraft having an airframe including a fuselage and a wing. The pedestal assembly includes an inboard pedestal supported by the airframe and positioned above the wing. The inboard pedestal includes an inboard bearing assembly disposed within an inboard pillow block housing. The pedestal assembly also includes an outboard pedestal supported by the airframe and positioned above the wing. The outboard pedestal includes an outboard bearing assembly disposed within an outboard pillow block housing. The inboard and outboard bearing assemblies are operable to receive the pylon assembly therein such that the pylon assembly is rotatably mounted between the inboard and outboard pedestals to selectively operate the tiltrotor aircraft between the helicopter mode and the airplane mode.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to an input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a spherical bearing providing a self-aligning coupling with the pylon assembly.

Abstract: A pedestal assembly receives a pylon assembly of a tiltrotor aircraft having an airframe including a fuselage and a wing. The pedestal assembly includes inboard and outboard tip ribs that extend above the wing and respectively define inboard and outboard slots. The pedestal assembly also includes inboard and outboard bearing cartridges. The inboard bearing cartridge is received within the inboard slot, is coupled to the inboard tip rib and includes an inboard bearing assembly. The outboard bearing cartridge is received within the outboard slot, is coupled to the outboard tip rib and includes an outboard bearing assembly. The inboard and outboard bearing assemblies are operable to receive the pylon assembly therein such that the pylon assembly is rotatably mounted between the inboard and outboard tip ribs to selectively operate the tiltrotor aircraft between a helicopter mode and an airplane mode.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to the input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a pillow block housing such as a full or a split pillow block housing.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard tip ribs extend above the wing and define slots. Inboard and outboard bearing cartridges are received in respective slots. The inboard and outboard bearing cartridges respectively include inboard and outboard bearing assemblies. A pylon assembly is rotatably coupled between the inboard and outboard bearing assemblies. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to the input gear of the spindle gearbox.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to an input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a spherical bearing providing a self-aligning coupling with the pylon assembly.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard tip ribs extend above the wing and define slots. Inboard and outboard bearing cartridges are received in respective slots. The inboard and outboard bearing cartridges respectively include inboard and outboard bearing assemblies. A pylon assembly is rotatably coupled between the inboard and outboard bearing assemblies. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to the input gear of the spindle gearbox.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to an input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a spherical bearing providing a self-aligning coupling with the pylon assembly.

Abstract: A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to the input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a pillow block housing such as a full or a split pillow block housing.