Abstract: An aspect provides a skid landing gear assembly including a cross member disposed between a first skid tube and a second skid tube, and a tension cable member configured to be disposed in the cross member; wherein the tension cable member resists outward deflection of at least a portion of the skid landing gear assembly when a downward load is applied to the skid landing gear assembly. In other aspects, there are methods of avoiding ground resonance in a skid landing gear assembly, methods of assembling a skid landing gear assembly, methods of operating a helicopter with a skid landing gear assembly, and methods of improving the service life of a skid landing gear assembly.

Abstract: An example of an aerial vehicle includes a rudder removably connected to the aerial vehicle by a twist lock mechanism. The twist lock mechanism is biased in a locked position by an elastic member.

Abstract: A mast lockout system for a tiltrotor aircraft having a proprotor assembly. The system includes a mast coupled to and rotatable with the proprotor assembly. A proprotor gearbox having a proprotor gearbox housing is operable to transmit torque and rotation energy to the mast. A lock assembly has first and second lock members. The first lock member is coupled to and rotatable with the mast. The second lock member is coupled to the proprotor gearbox housing. The lock assembly has a first position in which the first and second lock members are disengaged, thereby allowing rotation of the proprotor assembly. The lock assembly has a second position in which the first and second lock members are engaged, thereby preventing rotation of the proprotor assembly. The lock assembly is actuatable between the first and second positions.

Abstract: A navigation system for vehicles, such as rotorcraft, includes a directional gyroscope having a magnetic heading correction mode, a nonmagnetic manual heading correction mode and a nonmagnetic automatic heading correction mode. A magnetic field sensor is operably coupled to the directional gyroscope and is operable to generate magnetic north-based signals. A heading correction input is operably coupled to the directional gyroscope and is operable to generate manual signals upon actuation thereof. A global positioning system sensor is operably coupled to the directional gyroscope and is operable to generate track-based signals. In the magnetic heading correction mode, the directional gyroscope receives the magnetic north-based signals for heading corrections. In the nonmagnetic manual heading correction mode, the directional gyroscope receives the manual signals for heading corrections.

Abstract: An autopilot recoupling system for a rotorcraft having an automatic flight control system with multiple layers of flight augmentation. The autopilot recoupling system includes an autopilot recoupling input operable to generate an autopilot recoupling signal. An autopilot recoupling signal processor is communicably coupled to the autopilot recoupling input. The autopilot recoupling signal processor is configured to receive the autopilot recoupling signal from the autopilot recoupling input and responsive thereto, determine a state of the automatic flight control system, activate a trim systems layer of the automatic flight control system if the trim systems layer is not active, engage an attitude retention systems layer of the automatic flight control system if the attitude retention systems layer is disengage and recouple an autopilot systems layer of the automatic flight control system.

Abstract: A mast lockout system for a tiltrotor aircraft having a proprotor assembly. The system includes a mast coupled to and rotatable with the proprotor assembly. A proprotor gearbox having a proprotor gearbox housing is configured to transmit torque and rotation energy to the mast. A lock assembly has first and second lock members. The first lock member is coupled to the mast between first and second mast bearings and configured to rotate with the mast. The second lock member is coupled to the proprotor gearbox housing. The lock assembly has a first position in which the first and second lock members are disengaged, thereby allowing rotation of the mast. The lock assembly has a second position in which the first and second lock members are engaged, thereby preventing rotation of the mast. The lock assembly is actuatable between the first and second positions.

Abstract: An engine mount assembly for coupling an engine to an airframe. The engine mount assembly includes a torsion bar coupled to the engine and a lateral movement control assembly coupled between the torsion bar and the airframe. The lateral movement control assembly includes a spring having a lateral stiffness. The torsion bar rotates in response to lateral movement of the engine such that the lateral movement of the engine is controllable based on the lateral stiffness of the spring.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining rotational information associated with the component; receiving original data indicating the toothmesh frequency of the drive train; filtering the original data to remove energy above the toothmesh frequency; interpolating the filtered original data to generate an integer number of samples per tooth passage; and generating an amplified differential coherence (ADC). In some embodiments, an amplified differential coherence gearbox arrangement value (ADCT) is generated.

Abstract: A method for calculating torque through a rotor mast of a propulsion system of a tiltrotor aircraft includes receiving the torque being applied through a quill shaft of the rotorcraft. The quill shaft is located between a fixed gearbox and a spindle gearbox, and the spindle gearbox is rotatable about a conversion access. The torque through the rotor mast is determined by using the torque through the quill shaft and the efficiency loss value between the quill shaft and the rotor mast.

Abstract: According to one embodiment, a pitch link includes a first link, a second link coupled to a first end of the first link, a third link coupled to a second end of the first link opposite the first end, and a first bearing housing having a first bearing and a second bearing housing having a second bearing. The first bearing housing is removably coupled to the second link. The second link separates the first bearing housing from the first link. The second bearing housing is removably coupled to the third link. The third link separates the second bearing housing from the first link.

Abstract: According to one embodiment, a clutch may be coupled between a rotor system and a power train of a rotorcraft. The clutch may be operable to disengage the rotor system from the power train during operation of the power train. A clutch control system in communication with the clutch and include a rotorcraft condition sensor operable to sense an operating condition of the rotorcraft and a control unit operable to prevent the clutch from disengaging the rotor system from the power train if the operating condition of the rotorcraft fails to satisfy a predetermined criterion.

Abstract: A system and method for providing state comparison of redundant processors used, e.g. to control a rotor craft. A primary microprocessor is configured to receive input data from a position sensor and a flight condition sensor and determine therefrom a first desired control law state, and a secondary microprocessor is configured to receive input data from the position sensor and the flight condition sensor and determine therefrom a second desired control law state. The first desired control law state from the primary microprocessor and the second desired control law state from the secondary microprocessor are compared, and (a) the first desired control law state is entered when the first desired control law state and the second desired control law state match, and (b) a last known control law state is maintained when the first desired control law state and the second desired control law state do not match.

Abstract: A variable thrust cross-flow fan system for an aircraft including a rotatable wing member having a first housing member; an actuator assembly operably coupled to the first housing member; and a variable thrust cross-flow fan assembly including a first and second driver plates having a plurality of blades rotatably mounted therebetween. The plurality of blades has a circular path of travel when rotating and includes a control assembly coupled to the plurality of blades to generate a variable thrust force. The control assembly includes a control cam that is substantially non-rotatable relative to the first and second driver plates and a hinge member that is fixedly connected to the control cam and to the first housing member at a hinge axis. Rotation of the first housing member by the actuator assembly imparts rotation of the control cam about the hinge axis, thereby changing the direction of the variable thrust force.

Abstract: The present invention includes an anti-torque assembly for a helicopter comprising a plurality of fixed blade pitch motors mounted on one or more pivots on the tail boom of the helicopter, wherein the plurality of fixed blade pitch motors on the one or more pivots are adapted to be oriented substantially in-plane with a tail boom of a helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode.

Abstract: In some embodiments, a control manager is disposed between the rotor system and the flight control inceptor. The control manager is configured to receive control commands wirelessly from a ground control station, translate the control commands into one or more axes associated with the flight control inceptor, and transmit the translated control commands to the rotor system in place of the instructions received from the pilot via the flight control inceptor.

Abstract: A system and algorithm-based method of determining engine health and assuring available propulsion power based on historical data reflecting the individual engine's unique performance “fingerprint.

Abstract: Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body, and multiple motor assemblies coupled to the primary spool that provide selective displacement of the primary spool or the secondary spool. Each motor assembly includes a clutching mechanism that selectively couples a motor of the motor assembly to and from the primary spool.

Abstract: According to one embodiment, a gear includes a steel portion that is oriented on a center axis. The steel portion includes a hub, a cylindrical rim, a web, and a plurality of engagement features. The hub is centered about the center axis. The rim has an exterior surface and an interior surface that surrounds the hub and is centered about the center axis. The web extends from an exterior surface of the hub to the interior surface of the rim. The engagement features are on the exterior surface of the cylindrical rim. The gear also includes a first composite piece adjacent to a first side of the web, the first composite piece extending from the hub to the interior surface of the rim, wherein the first composite piece does not extend past the hub towards the center axis.

Abstract: A bearing liner allows a bearing to be mounted to a bearing housing even where the coefficients of thermal expansion of the bearing and the housing are different. The bearing liner includes a body portion and a mounting portion. The body portion has a cylindrical substrate that extends about a longitudinal axis of the bearing. The mounting portion includes mounting tabs that extend from the body portion of the liner. The mounting tabs allow the liner to be fixed to the housing and to the bearing. The mounting tabs are configured to flex relative to the body portion of the liner so as to allow for thermal expansion and contraction of the housing relative to the bearing while still securing the bearing to the housing.

Abstract: In one example embodiment, a filter condition measurement device features an engine data repository, one or more sensor units, and a measurement unit. The measurement system is configured to identify a first flow value corresponding to a sensed engine power value from the engine data repository, determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value; identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value; and determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value.