Abstract: A rotor system for an aircraft includes an open rotor assembly comprising an open rotor assembly comprising a plurality of rotor blades connected to a rotor mast, wherein the rotor assembly is tiltable relative to a wing of the aircraft between a first position corresponding to an airplane mode of the aircraft and a second position corresponding to a helicopter mode of the aircraft; 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 generating rotational energy to a motor shaft; and a gearbox connected to receive rotational energy from the at least one electric motor via the motor shaft and to provide rotational energy to the rotor mast via a rotor shaft, wherein the at least one electric motor is fixed relative to the wing of the aircraft.

Abstract: Various implementations described herein are directed to an aircraft having a multi-engine configuration with multiple engines. The aircraft may have a flight control system coupled to the multiple engines with a multi-engine interface. The flight control system may be configured to shutdown at least one engine of the multiple engines during reduced-engine operation by continuously calculating altitude for the reduced-engine operation based on one or more of an aircraft descent rate of the aircraft and an engine restart time of the at least one engine.

Abstract: A method for reducing form drag on a tailsitter aircraft during at least one of takeoff or landing includes vertically taking off from the ground in a tailsitter orientation. The method also includes determining an actual pitch of the tail sitter aircraft in the tailsitter orientation. The method also includes determining a difference between the actual pitch and a predetermined pitch. The method also includes adjusting a heading of the tailsitter aircraft based on the difference to minimize a pitch angle to reduce the form drag on the tailsitter aircraft.

Abstract: A reduced performance monitoring system for a tiltrotor aircraft includes a physical component of the tiltrotor aircraft configured to displace over time in response to an input, a simulation component configured to generate a simulated displacement response of the physical component, and a comparison module configured to compare a measured physical displacement response of the physical component to the simulated displacement response of the physical component.

Abstract: A torque measurement system determines torque on a shaft by monitoring angular deflection of the shaft under load using phase shift measurements. Calibration of the system uses a defined offset that is determined using a reference operating condition. The offset calibration value is determined for a rotorcraft using the following steps: defining a reference operational condition in which the shaft is rotating, estimating the torque at the reference condition based on aerodynamic knowledge of the rotors coupled to the shaft, operating the shaft at the reference operational condition, capturing sensor data to determine the phase difference at the operational condition, and associating the phase difference and an estimated torque as a calibration value to enable calculation of torque in the torque measurement system.

Abstract: An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

Abstract: A handle assembly for an access panel is described and includes a support structure attached to the access panel; a handle engaging with the support structure, the handle comprising a grip portion and upper and lower flanges extending perpendicularly from the grip portion; and a retention/extension mechanism for retaining the handle in a first position and for transitioning the handle to a second position after pressure is applied to and subsequently released from the handle.

Abstract: A spline assembly, including a spline shaft having a first end and a second end, wherein the first end is splined to engage a spline receiver of a primary drive system and includes a substantially spherical alignment head, wherein the spherical alignment head comprises an expendable hydrocarbon material that is caused to melt by operation of the primary drive system over time.

Abstract: In an aircraft, the airframe includes a windshield frame, with an energy attenuating windshield corner support extending across a corner of the windshield frame. The energy attenuating windshield corner support is configured to deform upon an impact to a windshield disposed in the windshield frame. This energy attenuating windshield corner support may be shaped and/or sized to enable, and/or comprised of a material that enables, the aircraft windshield corner support to deform upon the impact to the windshield disposed in the windshield frame, attenuating energy of the impact to the windshield disposed in the windshield frame.

Abstract: A dual-motor system includes a first motor rotationally coupled to a first drive shaft. The first drive shaft is coupled to a common shaft couplable to a rotationally driveable member. The dual-motor system also includes a second motor rotationally coupled to a second drive shaft. The second drive shaft is coupled to the common shaft. The first motor and the second motor are coaxially aligned with the first drive shaft passing through the second drive shaft.

Abstract: A system includes a driver monitor system configured to receive information about driver operation, a relationship table comprising information about an expected relationship between driver operation and a preload force, and a driver controller configured to control a driver in response to the information about driver operation and according to the relationship table. A method of managing a preload force includes providing a first component, providing a second component for compression against the first component, operating a driver to move the first component into contact with the second component, monitoring an operation of the driver, and determining an expected preload force in response to the operation of the driver.

Abstract: Methods and systems are described for increasing the safety of unmanned vehicles. Failure rates of components can be combined and adjusted if necessary given sensor data or statistical or historical data that impacts failure rates. The failure rates of components can be combined to give an overall failure or success rate for a vehicle and can be compared to an accepted failure or success rate in connection with a hazard. Hazards with heightened safety requirements can be avoided by a contingency maneuver if the unmanned vehicle's failure or success rate is not acceptable.

Abstract: A rotor-hub-flap anisotropic-sensor system includes a rotor hub, a plurality of anisotropic-sensor arrangements interoperably coupled to the rotor hub and operable to measure flapping of the rotor hub, a plurality of rotor blades connected to the rotor hub, and at least one flight control computer interoperably coupled to the plurality of anisotropic-sensor arrangements.

Abstract: An exemplary method to determine an airspeed and an angle of attack of a propeller powered vehicle includes determining the power delivered to the propeller, the air density, a propeller power coefficient, an advance ratio for the propeller, and the airspeed using the advance ratio and determining the angle of attack using the airspeed.

Abstract: The present invention includes a hybrid propulsion system for an aircraft comprising: an engine disposed within a fuselage of the aircraft, two electrical generators disposed within the fuselage and connected to the engine, and two nacelles. Each nacelle comprises a proprotor, and each nacelle houses two electric motors connected to the proprotor. Each electrical generator is connected to the two electric motors in each nacelle. The proprotors provide lift for vertical takeoff and landing in a helicopter mode. A fan is coupled to the fuselage and connected to two additional electric motors. Each additional electric motor is connected to one of the two electric generators. The fan provides thrust for forward flight during an airplane mode. The airplane mode includes increasing power to the fan while decreasing power to the proprotors to zero.

Abstract: A drive system for a rotorcraft includes first and second gearbox assemblies and a lubrication assembly. The lubrication assembly includes first and second lubrication systems and a valve connected between the first and second lubrication systems such that when the valve is in a first position, a test mode of operation of the lubrication assembly is enabled and when the valve is in a second position, a normal mode of operation of the lubrication assembly is enabled. The lubrication assembly also includes a valve control unit operable to instruct the valve to selectively move between the first position and the second position.

Abstract: Systems, methods and non-transitory computer readable storage media for airspace management within an airspace region at a node of a peer to peer network having a plurality of nodes and maintaining a blockchain containing a current deconflicted flight schedule for the airspace region. One method includes receiving requests for airspace reservations, each including flight plan data, from other nodes over the peer to peer network, compiling the flight plan data to identify conflicts between the requests and the current deconflicted flight schedule, validating the flight plan data of the requests that do not conflict with the current deconflicted flight schedule to generate validated airspace reservations, creating a block containing the validated airspace reservations and interlinking the block with the blockchain such that the blockchain contains a new deconflicted flight schedule for the airspace region for broadcast to the other nodes over the peer to peer network.

Abstract: A lockout system for an aircraft having a rotor assembly. The lockout system includes a drive shaft coupled to and rotatable with the rotor assembly, a nonrotating airframe structure disposed proximate the drive shaft and a lock assembly having first and second lock members. The first lock member is rotatable with the drive shaft and includes a plurality of bearing assemblies. The second lock member is coupled to the nonrotating airframe structure and includes a cradle having a plurality of asymmetric slots each with a leading ramp and a trailing stop. The lock assembly has a disengaged position in which rotation of the drive shaft is allowed and an engaged position in which each of the bearing assemblies is seated within one of the asymmetric slots to prevent rotation of the drive shaft. The lock assembly is actuatable between the engaged and disengaged positions.

Abstract: An ice protection system is configured for a rotor blade having a leading edge along at least a portion of a spanwise length extending between a root portion and a tip portion. The system has an electric spanwise anti-ice heater configured for placement on the leading edge of the blade and a first electric spanwise de-ice heater adjacent the anti-ice heater and having varying chordwise dimensions. The de-ice heater is configured for placement on an upper surface of the blade or a lower surface of the blade. Electrical connectors for each heater are configured for connection near the root portion of the blade to a source of electrical power.

Abstract: Disclosed is an assembly and a vehicle and apparatus including the assembly, for maintaining a vehicle door in an open position may include at least one rod member configured to connect at a first end to the door and at a second end to a vehicle frame. A tab may be connected to and extend in at least one direction from the rod member. A plunger may be configured to be anchored in the door and including a pin configured to extend from and retract into the plunger. The pin may be configured to engage the tab when extended and disengage from the tab when retracted.