Abstract: A computer-implemented method for matching material names from one or more material sources with safety data sheet material names from one or more safety data sheets. The method includes: extracting the material names from the one or more material sources; preprocessing the material names and removing extraneous data from one or more of the material names; selecting one of the material names; comparing the selected material name with the safety data sheet material names; identifying the safety data sheet material names that match the material name; and transmitting an output to a user device to display the material name and the matching safety data sheet material names.

Abstract: A rotor system for an aircraft includes an open rotor assembly comprising a plurality of rotor blades connected to a rotor mast via a yoke, wherein the rotor assembly is tiltable between a first position corresponding to an airplane mode and a second position corresponding to a helicopter mode; and a drive system for providing rotational energy to the open rotor assembly via the rotor mast, the drive system comprising at least one electric motor for providing rotational energy to a drive shaft and a gearbox connected to the drive shaft for receiving rotational energy from the at least one electric motor via the drive shaft and providing rotational energy to the rotor mast via a rotor shaft; wherein the drive system is rotatable relative to the wing about a tilt axis and the rotor shaft is coaxial with the drive shaft.

Abstract: A ducted-rotor aircraft includes a fuselage and first and second ducts that are coupled to the fuselage. Each duct includes a duct ring, a rotor having a plurality of blades, a hub that positions the rotor such that the blades define a blade plane of rotation within the duct ring, and a plurality of stators that are coupled to the hub at respective locations aft of the blade plane of rotation. Each of the plurality of stators defines a leading edge that is slanted toward the blade plane of rotation. The leading edges of the stators are slanted to follow a contour defined by the blades. The leading edges may also be slanted to maintain a distance of at least one blade inboard chord length between the leading edges of the stators and respective trailing edges of the blades.

Abstract: A rotor system for an aircraft includes an open rotor assembly comprising a plurality of rotor blades connected to a rotor mast via a yoke, wherein the rotor assembly is tiltable between a first position corresponding to an airplane mode and a second position corresponding to a helicopter mode; and a drive system for providing rotational energy to the open rotor assembly via the rotor mast, the drive system comprising at least one electric motor for providing rotational energy to a drive shaft and a gearbox connected to the drive shaft for receiving rotational energy from the at least one electric motor via the drive shaft and providing rotational energy to the rotor mast via a rotor shaft; wherein the drive system is rotatable relative to the wing about a tilt axis and the rotor shaft is coaxial with the drive shaft.

Abstract: A rotor system for an aircraft is described and includes an open rotor assembly comprising a plurality of rotor blades connected to a rotor mast; and a drive system for providing rotational energy to the open rotor assembly via the rotor mast. The drive system includes at least one electric motor for providing rotational energy to a motor shaft; and a gearbox connected to the drive shaft for receiving rotational energy from the at least one electric motor via the motor shaft and providing rotational energy to the rotor mast via a rotor shaft.

Abstract: A rotor system includes a rotor assembly and a duct system. The rotor assembly includes rotor blades extending from a mast axis and configured to rotate about the mast axis. The duct assembly includes a moveable duct portion and a stationary duct portion. In a first duct configuration, the moveable duct portion surrounds a first portion of the rotor assembly, the stationary duct portion surrounds a second portion of the rotor assembly, and the moveable duct portion and the stationary duct portion enclose the rotor assembly. In a second duct configuration, the stationary duct portion surrounds the second portion of the rotor assembly, and the moveable duct portion is moved away from the first portion of the rotor assembly, such that the rotor assembly is not enclosed.

Abstract: In an embodiment, a duct for a ducted-rotor aircraft includes a hub, the hub including a rotor and one or more motors configured to drive the rotor. The duct also includes a duct ring that defines an opening surrounding at least a portion of the hub. The duct also includes a plurality of stators that extend outward from the hub. The duct also includes at least one battery electrically coupled to the rotor and configured to power the one or more motors.

Abstract: A rotor system includes a rotor duct; at least one rotor blade that includes an outboard end; a tip extension mechanism affixed at the outboard end of the at least one rotor blade, the tip extension mechanism including at least one shim, the at least one rotor blade with the tip extension mechanism affixed thereto including an extended rotor blade; and a blade tip affixed to an outboard end of the extended rotor blade, wherein the blade tip is affixed to the extended rotor blade via at least one removable fastener.

Abstract: An aircraft having multiple wing planforms. The aircraft includes an airframe having first and second half-wings with first and second pylons extending therebetween. A distributed thrust array is attached to the airframe. The thrust array includes a plurality of propulsion assemblies coupled to the first half-wing and a plurality of propulsion assemblies coupled to the second half-wing. A flight control system is coupled to the airframe. The fight control system is configured to independently control each of the propulsion assemblies and control conversions between the wing planforms. The aircraft is configured to convert between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. In addition, the aircraft is configured to convert between a biplane configuration and a monoplane configuration in the forward flight orientation.

Abstract: A proprotor system for a ducted aircraft convertible between a vertical takeoff and landing flight mode and a forward flight mode includes a plurality of proprotor blades and a duct surrounding the proprotor blades. The duct includes an adaptive geometry device movable into various positions including a hover position and a cruise position. One or more actuators coupled to the adaptive geometry device are configured to move the adaptive geometry device between the hover position and the cruise position based on the flight mode of the ducted aircraft, thereby improving flight performance of the ducted aircraft.

Abstract: A fitting for securing a rotor blade in pivotable engagement with a yoke that is coupled to a mast of an aircraft for rotation therewith about a mast axis has a body that extends from an inboard end to an outboard end. The body of the fitting has an opening that extends into the body from the outboard end and that is adapted to receive a root end of the blade. The body further has a first bearing race that is defined along an outer surface of the body and is located between the inboard and outboard ends. The body further has an array of apertures that is located between the inboard end and the first bearing race, each aperture adapted to receive a respective fastener for retaining the blade within the opening.

Abstract: A tip gap monitoring system for a ducted aircraft having a proprotor system including a duct and a plurality of proprotor blades includes sensors coupled to the proprotor system. The sensors are configured to detect one or more parameters of the proprotor system to form a plurality of sensor measurements. The tip gap monitoring system also includes a flight control computer in data communication with the sensors. The flight control computer includes a tip gap measurement module configured to determine a tip gap distance between the duct and the proprotor blades based on the sensor measurements.

Abstract: A rotor assembly configured to increase the stiffness of a rotor mast. The rotor assembly includes the rotor mast, a rotor hub, a mast nut, a mast bearing, and a cuff disposed between the mast nut and the mast bearing. The cuff is captured and compressed between the mast nut and the inner race of the mast bearing along an uninterrupted load path that extends between the mast nut and the mast bearing.

Abstract: A bearing system includes an inboard bearing assembly and an outboard bearing assembly. The inboard bearing assembly includes an inboard fitting and an inboard race. The inboard fitting includes a plate with a convex mating surface and a first aperture formed through the plate for receiving a blade root of a rotor blade. The inboard race comprising a concave mating surface configured to receive the convex mating surface a second aperture formed the inboard race. The outboard bearing assembly includes an outboard bearing assembly comprising an outboard fitting having an aperture formed therethrough for receiving the blade root of the rotor blade.

Abstract: One embodiment is a rotor system comprising a duct ring; a hub disposed centrally to the duct ring; first and second stators each connected between the duct ring and the hub; first and second control vanes rotatably connected to the first and second stators, respectively; a structural hoop having a first end connected to the first control vane and a second end connected to the second control vane, the structural hoop for translating rotation of the first control vane about a vane axis to the second control vane; and a mechanism for restricting at least one of forward-aft movement and side-to-side movement of the structural hoop relative to the duct ring.

Abstract: A spherical bearing centrifugal force retention link includes an inboard spherical bearing to attach to a rotor hub and an outboard spherical bearing to attach to a rotor blade. In use, the inboard spherical bearing and the outboard spherical bearing react centrifugal force radially and a torsional moment of the centrifugal force link is substantially constant throughout the rotor blade pitch range.

Abstract: A spherical bearing centrifugal force retention link includes an inboard spherical bearing to attach to a rotor hub and an outboard spherical bearing to attach to a rotor blade. In use, the inboard spherical bearing and the outboard spherical bearing react centrifugal force radially and a torsional moment of the centrifugal force link is substantially constant throughout the rotor blade pitch range.

Abstract: A rotor assembly including a rotor mast, a rotor hub coupled to the rotor mast, a plurality of rotor blades coupled to the rotor hub, a control tube extending through the rotor mast, a crosshead coupled to the control tube, and a mechanism configured to drive the rotor mast in rotation. Wherein the mechanism is longitudinally positioned between a top portion and a bottom portion of the control tube and translation of the control tube relative to the rotor mast causes rotation of the rotor blades about their pitch-change axes. While the crosshead is installed, the crosshead is prevented from angular rotation about the mast axis. A pin of a rotor blade assembly is captured between opposing tabs of the crosshead and movable relative to the opposing tabs in response to translation of the crosshead along the mast axis.

Abstract: A seal system for coaxially aligned shafts includes an input shaft and an output shaft coaxially aligned with the input shaft. The seal system includes a seal adapter support housing coupled to the output shaft and a seal positioned between an end of the input shaft and an end of the seal adapter support housing. The input shaft is configured to rotate at a speed that is different than a speed of the output shaft.

Abstract: A tip gap control system for a ducted aircraft includes a flight control computer including an inner duct surface control module configured to generate an inner duct surface actuator command and a proprotor system in data communication with the flight control computer. The proprotor system includes a duct having active inner duct surfaces movable into various positions including a retracted position and an extended position. The proprotor system also includes proprotor blades surrounded by the duct and one or more actuators coupled to the active inner duct surfaces. The one or more actuators move the active inner duct surfaces between the various positions based on the inner duct surface actuator command, thereby controlling a tip gap between the proprotor blades and the duct.