Abstract: A man portable aircraft system includes first and second wings with first and second pylons couplable between pylon stations thereof to form an airframe. Each of a plurality of propulsion assemblies is couplable to one of a plurality of nacelle stations of the wings to form a two-dimensional distributed thrust array. A flight control system is couplable to the airframe and is operable to independently control each of the propulsion assemblies. A payload is couplable between payload stations of the first and second pylons. A man portable container is operable to receive the wings, pylons, propulsion assemblies, flight control system and payload in a disassembled configuration. The connections between the wings, pylons, propulsion assemblies and payload are operable for rapid in-situ assembly. In an assembled configuration, the aircraft is operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation.

Abstract: Systems and methods for automated configuration of mission specific aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation.

Abstract: In a first aspect, there is a method of making a rotor blade, including designing at least one of an upper skin, a lower skin, a support network, and components therefor; and forming at least one of the upper skin, the lower skin, a support network, and components therefor using an additive manufacturing process. In a second aspect, there is an airfoil member having a root end, a tip end, a leading edge, and a trailing edge, the airfoil member including an upper skin; a lower skin; and a support network having a plurality of interconnected support members in a lattice arrangement and/or a reticulated arrangement, the support network being configured to provide tailored characteristics of the airfoil member. Also provided are methods and systems for repairing an airfoil member.

Abstract: A mission configurable aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation. The aircraft includes an airframe having first and second wings with first and second pylons extending therebetween. A two-dimensional distributed thrust array is attached to the airframe. The thrust array including a plurality of inboard propulsion assemblies coupled to first and second inboard nacelle stations of the first and second wings. The thrust array also includes a plurality of outboard propulsion assemblies coupled to first and second outboard nacelle stations of the first and second wings. A flight control system is operable to independently control each of the propulsion assemblies. A payload is coupled to the airframe. The inboard propulsion assemblies have a thrust type that is different from the thrust type of the outboard propulsion assemblies.

Abstract: An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation. The aircraft includes an airframe having first and second wings with first and second pylons extending therebetween. The first and second wings each having first and second outboard nacelle stations. A two-dimensional distributed thrust array is attached to the airframe. The thrust array including a plurality of outboard propulsion assemblies coupled to the first and second outboard nacelle stations of the first and second wings. A flight control system is coupled to the airframe and is operable to independently control each of the propulsion assemblies. A cargo hook module is coupled to the airframe. The cargo hook module is operable for external load operations.

Abstract: According to one embodiment, a rotorcraft includes a body, a rotor blade, a drive system that can be operated to rotate the rotor blade, and an emergency valve control unit. The drive system contains a first gearbox assembly, a second gearbox assembly, a first lubrication system that can deliver lubricant to the first gearbox assembly, and a second lubrication system that can deliver lubricant to the second gearbox assembly. The drive system also contains an emergency valve that can be opened to deliver lubricant from the first lubrication system to the second gearbox assembly. The emergency valve control unit can instruct the emergency valve to open.

Abstract: A flapping control system for a proprotor assembly of a tiltrotor aircraft includes one or more sensors operable to detect one or more flight parameters of the tiltrotor aircraft to form sensor data. The sensors include a proprotor flapping sensor to detect a proprotor flapping measurement. The flapping control system includes a flapping control module in data communication with the sensors. The flapping control module includes a maneuver detection module to detect whether the tiltrotor aircraft is in a maneuver mode using the sensor data. The flapping control module identifies a maneuver flapping threshold associated with the maneuver mode. The flapping control module generates a swashplate command using the proprotor flapping measurement and the maneuver flapping threshold, and sends the swashplate command to the proprotor assembly to reduce flapping of the proprotor assembly.

Abstract: A rotor hub assembly that includes a yoke configured to attach blades thereto, a universal joint configured to attach to, and transmit forces between, a mast and the yoke, and an elastomeric member configured to attenuate vibrations transmitted from the universal joint to the mast.

Abstract: A method of optimizing a planetary gear system for continued operation after failure of a planet gear includes providing a planetary gear system and reducing a backup ratio of a planet gear of the planetary gear system by reducing a rim thickness of the planet gear.

Abstract: A method of avoiding gear tooth interference in a planetary gear system includes designing and building a planetary gear system comprising a selected base pitch and tooth length for planet gears, breaking a rim of one of the planet gears, and verifying whether tooth tip interference occurs during operation of the planetary gear system.

Abstract: A clutch that has a synchronizer for matching a rotational velocity of a drive input with a rotational velocity of a driven output prior to engagement of a locking mechanism.

Abstract: In some embodiments, an aircraft includes a flying frame having an airframe, a distributed propulsion system attached to the airframe, a flight control system operably associated with the distributed propulsion system and a pod assembly selectively attachable to the flying frame. The distributed propulsion system includes a plurality of propulsion assemblies that are independently controlled by the flight control system, thereby enabling the flying frame to have a vertical takeoff and landing mode and a forward flight mode.

Abstract: An aircraft is described and includes a fuselage, a wing coupled to the fuselage, and a rotor system including a proprotor system and an engine. An interconnect driveshaft gear is configured to communicate mechanical energy between a gearbox and an interconnect driveshaft. An accessory gear is coplanar with and in mechanical communication with the driveshaft gear. A proprotor gear is coplanar with and in mechanical communication with the interconnect driveshaft gear and the accessory gear and communicates mechanical energy to the proprotor system. An engine gear coplanar and in mechanical communication with the interconnect driveshaft ear, the accessory gear, and the proprotor gear transmits mechanical energy to the proprotor system via the proprotor gear.

Abstract: A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode. The proprotor system includes a yoke having a plurality of blade arms with inboard pockets. A centrifugal force and shear bearing assembly is disposed in each of the inboard pockets of the yoke. Each of a plurality of proprotor blades is coupled to the yoke by one of the bearing assemblies such that each proprotor blade has a pitch change degree of freedom about a pitch change axis and a tilting degree of freedom about a focal point. Each bearing assembly includes a centrifugal force bearing coupled to the yoke, a shear bearing coupled to the yoke and an inboard beam coupled between the centrifugal force bearing and the shear bearing. Each inboard beam is coupled to a respective proprotor blade.

Abstract: A mechanism for folding a rotor blade that is rotatably coupled to a blade cuff about a blade-fold axis between an extended position and a folded position. The mechanism includes a swash plate configured to translate relative to a mast, a pitch link rotatably coupled to the swash plate, a pitch horn rotatably coupled to the pitch link, a crank coupled to the pitch horn, and a link rotatably coupled to the crank and rotatably coupled to the rotor blade. The pitch horn and the crank being configured to commonly rotate relative to the blade cuff about a crank axis in response to translation of the swash plate, wherein the crank axis passes through the blade cuff.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. Hub bolts couple each of the bearing cages to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assemblies and the yoke inboard of the inboard pockets.

Abstract: A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode includes a yoke having a plurality of blade arms each having an inboard pocket with a load transfer surface. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets. Each of a plurality of inboard beams is disposed at least partially between a centrifugal force bearing and a shear bearing of each bearing assembly and has a proprotor blade coupled thereto. Each of a plurality of independent shoes is coupled between one of the centrifugal force bearings and the yoke. Each shoe has a load transfer surface that has a contact relationship with the load transfer surface of the respective inboard pocket forming a centrifugal force load path therebetween.

Abstract: A bearing assembly for coupling a proprotor blade to a yoke in a proprotor system. The bearing assembly is positionable within an inboard pocket of a blade arm of the yoke. The proprotor system is operable for use on a tiltrotor aircraft having helicopter and airplane flight modes. The bearing assembly includes a centrifugal force bearing and a shear bearing having an inboard beam coupled therebetween. The centrifugal force bearing has a mating surface, a lateral movement constraint feature and at least one radially extending anti-rotation feature. The inboard beam has a mating surface in a contact relationship with the mating surface of the centrifugal force bearing, a lateral movement constraint feature operably associated with the lateral movement constraint feature of the centrifugal force bearing and at least one radially extending anti-rotation feature that corresponds with the at least one radially extending anti-rotation feature of the centrifugal force bearing.

Abstract: A proprotor system for a tiltrotor aircraft includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets. Each of a plurality of inboard beams is disposed at least partially between a centrifugal force bearing and a shear bearing of each bearing assembly and has a proprotor blade coupled thereto. Each of a plurality of latch assemblies selectively couples one of the bearing assemblies to the yoke. Each latch assembly is rotatable relative to the yoke between an engaged position wherein the latch assembly is engagable with one of the bearing assemblies to couple the bearing assembly to the yoke and a disengaged position wherein the latch assembly is disengaged from the respective bearing assembly enabling installation and removal of the respective bearing assembly relative to the respective pocket.

Abstract: A variable-speed gearbox for a tiltrotor with fixed engine and rotating proprotor includes an input shaft coupled to the respective fixed engine, an output shaft coupled to the respective proprotor; a high-speed clutch integrated into a high-speed gear train, the high-speed gear train having an input coupled to the input shaft and an output coupled to the output shaft; and a low-speed clutch integrated into a low-speed gear train, the low-speed gear train having an input coupled to the input shaft and an output coupled to the output shaft. The high-speed clutch and the low-speed clutch can be freewheeling clutches capable of disconnecting the output and the input of the respective gear train of the high and low-speed gear trains in an overrunning condition when the output rotates faster than the input of the respective gear train. The low-speed clutch can be permanently engaged. In accordance to some embodiments the variable-speed gearboxes may include an accessory drive.