Abstract: In an embodiment, a method includes acquiring a current condition indicator of a condition indicator set associated with an operating condition of a machine, the condition indicator set indicating sensor readings associated with an operating element of the machine under the operating condition. The method also includes determining, by a data server, a relative trend significance over a trend window of the condition indicator set based, at least in part, on an evaluation of the trend window in relation to a historical window of the condition indicator set. The method also includes determining, by the data server, whether trend criteria associated with the operating element is satisfied, where the trend criteria may include criteria related to the relative trend significance. The method also includes executing, by the data server, an alerting process in response to the determining that the trend criteria is satisfied.

Abstract: Systems and methods include providing an aircraft with a flight control system, a hybrid electrical or hybrid hydraulic propulsion system, and three ducted fan configuration. Each of two ducted fore fans include a single rotor system having multiple rotor blades, and a single ducted aft fan includes dual, coaxial, counter-rotating rotor systems each having multiple rotor blades. The aircraft is a vertical takeoff and landing (VTOL) aircraft that is capable of operation in an airplane mode and a helicopter mode and designed to provide an urban air-taxi that would relieve ground traffic congestion, reduce carbon emissions, and increase productivity, thereby providing a faster, more efficient means of transportation.

Abstract: The present invention includes a bypass apparatus for lubricant in an unregulated pressurized gearbox including: a block including a lubricant inlet in fluid communication with a pressure relief valve, wherein the pressure relief valve diverts lubricant into the gearbox or into an oil filter, wherein lubricant is returned to the gearbox when the lubricant is cold and/or pressure at the pressure relief valve is high to reduce damage to the gearbox caused by high pressure during a cold start, and when the lubricant temperature increases and the pressure is reduced the pressure relief valve closes and lubricant enters the oil filter.

Abstract: A rotorcraft including a main rotor, flight controls connected to the main rotor the main rotor, a plurality of engines connected to the main rotor and operable to drive the main rotor, a main rotor revolutions per minute (RPM) sensor, and a monitoring system operable to determine an engine failure of the plurality of engines. The monitoring system is further operable to engage an automated autorotation entry assist process in response to at least determining the engine failure and according to the measured main rotor RPM, where the automated autorotation entry assist process comprises the monitoring system generating one or more rotor RPM related commands according to at least a target main rotor RPM and the measured main rotor RPM, where the automated autorotation entry assist process further comprises controlling the one or more flight controls according to the one or more rotor RPM related commands.

Abstract: According to one implementation of the present disclosure, a method for determining airspeed for an unpowered vehicle is disclosed. The method includes: during flight, determining, by an accelerometer disposed on the unpowered vehicle, first and second accelerometer outputs, where the first and second accelerometer outputs correspond to respective first and second body-fixed load factor measurements; determining an angle-of-attack parameter; determining a body Z-force coefficient based on the angle-of-attack parameter; and determining an airspeed value based on the second body-fixed load factor measurement and the second body-fixed coefficient.

Abstract: A system includes an input/output interface, a processor, and a non-transitory computer-readable medium having instructions stored thereon. The instructions, when executed, cause the processor to receive a fault code, display on the input/output interface a first component of an aircraft that is associated with the fault code, upon selection by a user of a first hyperlink associated with the first component, display a physical layout of the aircraft in which the first component is indicated, and upon selection by the user of a second hyperlink associated with the first component, display a first wiring diagram of the aircraft in which the first component is indicated.

Abstract: In some embodiments, a rotorcraft may include a yoke, a blade, a spindle associated with the yoke, and an elastomeric bearing assembly. The center length of the spindle may define a center axis that passes through a center of the elastomeric bearing assembly. The elastomeric bearing assembly may contain a housing coupled to the blade and disposed around the center axis that is configured to rotate in relation to the center axis. The elastomeric bearing assembly may contain an elastomeric shear bearing that has an interior portion coupled to the spindle and an exterior portion coupled to the housing. The elastomeric bearing assembly may contain an elastomeric centrifugal force bearing pressed against the housing. The shear bearing may be configured to counteract a torsional force, and the centrifugal force bearing may be configured to counteract a compression force.

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

Abstract: An architecture for an electric distributed propulsion system includes one or more generators connected to a gearbox, a first and a second plurality of motors connected to the one or more generators, each motor of the plurality of motors connected to a blade to provide thrust, a first and a second power bus electrically connected between the one or more generators and the first and the second plurality of motors, each power bus independent of the other power bus, a first and a second controller independently connected to each of the first and second plurality of motors, each of the first and second controllers serving as a primary and a backup controller to provide redundant control to both the first and the second plurality of motors, and dual channels in communication between pilot input sensors and the first and the second controllers, each channel of the dual channels independent of the other channels, and the dual channels including an additional channel to provide redundant communication to the first an

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: 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 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.

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 proprotor blade for a ducted aircraft including a duct includes a main body having a distal end and a sacrificial blade tip coupled to the distal end of the main body. The sacrificial blade tip includes a deformable core material and a shell layer at least partially covering the deformable core material. The sacrificial blade tip deforms upon contact with the duct, thereby reducing damage to the ducted aircraft.

Abstract: A proprotor system for a ducted aircraft includes a duct and proprotor blades surrounded by the duct. Each proprotor blade is rotatable about a respective pitch change axis. The proprotor blades are configured to change collective pitch about the pitch change axes. The proprotor blades are extendable along the pitch change axes into various positions including a retracted position and an extended position. The proprotor blades change between the retracted position and the extended position based on the collective pitch of the proprotor blades, thereby controlling a tip gap between the proprotor blades and the duct.

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; and 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.

Abstract: A system for storing and supplying water to an internal combustion engine of a motor vehicle with a reservoir (1) for the water, with at least a delivery pump (5) for the water, and with at least a pipeline system comprising at least a feed line (4) to a consumer which is preferably designed in the form of at least a metering unit, and at least a return line (9) into the reservoir (1) as well as with means for demineralizing the water which are disposed inside the reservoir (1) or in the pipeline system.

Abstract: A proprotor system for a ducted aircraft includes a duct and proprotor blades surrounded by the duct. Each proprotor blade is rotatable about a respective pitch change axis. The proprotor blades are configured to change collective pitch about the pitch change axes. The proprotor blades are extendable along the pitch change axes into various positions including a retracted position and an extended position. The proprotor blades change between the retracted position and the extended position based on the collective pitch of the proprotor blades, thereby controlling a tip gap between the proprotor blades and the duct.

Abstract: An oleo strut includes an outer cylinder forming a first fluid chamber and an inner cylinder forming a second fluid chamber. The inner cylinder is adapted for sliding concentrically within the outer cylinder in a longitudinal direction. An orifice plate, which is located within the inner cylinder, has holes for fluidly coupling the first fluid chamber with the second fluid chamber. A free-floating washer is constrained in a slot of the orifice plate adjacent the holes and is adapted to move in the longitudinal direction for alternatively blocking and unblocking at least a portion of the holes. During compression of the oleo strut, fluid pushes the washer away from the holes for reducing resistance to fluid flow. During extension of the oleo strut, fluid pushes the washer against the orifice plate covering at least a portion of the holes, which increases the damping force and reduces the extension speed.

Abstract: A mount system for tiltably supporting a pylon assembly of a rotorcraft. First, second, third and fourth pylon links are each coupled between the pylon assembly and the airframe of the rotorcraft. The first pylon link has a first axis, the second pylon link has a second axis, the third pylon link has a third axis and the fourth pylon link has a fourth axis. Each of the axes intersects at a focal point located proximate a coaxial rotor system having counter-rotating upper and lower rotor assemblies such that the focal point provides a virtual pivot point about which the pylon assembly tilts to generate a control moment about a center of gravity of the rotorcraft that counteracts lateral and fore/aft moments generated by the upper and lower rotor assemblies during rotorcraft maneuvers.