Abstract: One embodiment is a rotor assembly for an aircraft, the rotor assembly comprising a plurality of rotor blades, wherein at least one of the rotor blades comprises a rotor alignment drag assembly comprising a drag structure on a surface of the at least one of the rotor blades, wherein the drag structure is moveable between a first position in which the drag structure is stowed within the at least one of the rotor blades, and a second position in which the drag structure is extended from the surface of the at least one of the rotor blades; and an actuation mechanism for moving the drag structure from the first position to the second position when a speed of the rotor assembly falls below a first threshold speed.

Abstract: A tactile signal seat belt sleeve has tactile signal producing elements arrayed along a sleeve that is adapted to fit over a seat belt for a vehicle, such as an aircraft. The elements may be arranged, for example, along the body-facing side of the belt. Each sleeve incorporates a signal-receiving element that allows for the activation of vibration-producing motors embedded in the fabric of the seat belt sleeve or belting. Vibration motors, such as piezoelectric devices, can be used to produce the tactile feedback. The haptic feedback assembly is connected to an interface unit that uses data from aircraft systems to sense, for example, the aircraft altitude and pitch, roll and yaw system. The interface unit generates signal to haptic devices to create appropriate vibrations patterns to the sleeve. The vibrations may be used to indicate directions of turn using output signals from various navigations systems.

Abstract: An automatic aircraft powerplant control system includes a throttle servo for adjusting a throttle valve via a throttle control linkage. A throttle control lever provides a user input to the throttle servo, and a throttle controller controls the throttle servo for controlling a throttle valve. A propeller servo is provided for adjusting a propeller governor setting of an engine. A propeller control lever provides a user input to the propeller servo, and a propeller controller controls the propeller servo. A mixture control servo is configured for providing a mixture control output to the engine via a mixture control linkage for adjusting an air-fuel mixture. A mixture controller is configured for controlling the mixture control servo.

Abstract: A system is provided for controlling the pitch of blades of a rotor, the system comprising an actuator for each blade, each actuator being configured for selective control of the pitch of an associated blade about a pitch axis. Sensors are configured for determining aerodynamic forces acting on the rotor, and a flight control system is configured to receive signals from the sensors and for operating the actuators in response to the signals to achieve a desired pitch-flap coupling value.

Abstract: Personnel working at elevated positions use safety lines to prevent falls. Equipment being used in proximity to the personnel may interfere with the safety lines presenting a potential hazard. A fall protection monitor provides an automated and wireless sensor system for avoiding interactions between equipment and safety lines. The fall-protection monitor includes a first sensor for monitoring whether a safety line is in operation. A second sensor monitors a location of a moveable device being used in the vicinity of the safety line. A controller determines the location of the moveable device and whether the safety line is in operation. The controller prevents movement of the moveable device within a predetermined distance from an operational safety line.

Abstract: A seabased resupply system includes a fuel containment structure containing fuel and extending fore and aft along a longitudinal axis, a pump on the fuel containment structure operable to pump the fuel, containers located on an exterior of opposite lateral sides of the fuel containment structure, and an operating system located inside one or more of the containers, the operating system comprising at least one selected from a power supply, a communication system, and a control processor.

Abstract: Systems and methods include providing an aircraft with a fuselage and a convertible engine disposed within the fuselage. The convertible engine is operable as a turbofan engine in a thrust mode and a turboshaft engine in a shaft power mode. The convertible engine includes a housing, an engine core having a low pressure turbine shaft, and a bypass fan system. The bypass fan system includes a bypass fan having a fan clutch. The fan clutch selectively couples at least a portion of the bypass fan to the low pressure turbine shaft when the convertible engine is operated in the thrust mode and decouples at least a portion of the bypass fan from the low pressure turbine shaft when the convertible engine is operated in the shaft power mode.

Abstract: Breathing systems and methods for a gearbox is described. Embodiments preferably create a closed system for air within the gearbox. As an operating gearbox warms the air or fluid within, or an altitude change causes air to expand or contract, increased pressure can result and air can escape through tubing to a cannister. The cannister can receive the expanding air in an impermeable cavity that is proximate to a bladder open or partially open to an exterior environment. Air can press on the bladder, expanding the cavity and shrinking the bladder until a pressure equilibrium is reached. As operation of the gearbox is lowered or powered off, or another altitude change occurs, the air can cool and/or retract into the gearbox. The bladder can then expand and press on the cavity until equalizing the pressure within the cannister.

Abstract: Briefly, the disclosure relates to apparatuses and methods to enclose electrical contacts for de-icing equipment utilized on fixed-wing aircraft and rotary-wing aircraft, such as helicopters and tiltrotor aircraft. In some implementations, enclosing electrical contacts for a de-ice heater blanket may ensure that high-quality electrical connections are made between conductors of one or more de-icing cables and the electrical contacts of the de-ice heater blanket. Such high-quality electrical connections may be maintained even during aircraft operations conducted in below-freezing ambient environments, rainy and/or wet environments, dusty desert environments, and so forth.

Abstract: A cam-locking system for use with a retractable driveshaft that includes a housing, a cam carrier located at least partially in the housing, and a cam rotatably coupled to the cam carrier. Translation of the cam carrier along a central axis allows the cam to rotate into cooperative engagement with a catch recess on an interior surface of the housing, preventing the cam carrier from translating backwards, and thereby maintaining the retractable driveshaft in an engaged position. Further advancement of the cam carrier allows that cam to rotate into and unlocking gap in the interior surface of the housing, which enables the cam carrier to translate backwards along the central axis below the locked position, thereby disengaging the retractable driveshaft.

Abstract: An autonomous thrust vectoring ring wing pod is disclosed. A plurality of distributed propulsion element (thruster) layout within a self-articulating ring wing pod allows the pod to selectively control its thrust vector by controlling each propulsion element in the pod. This arrangement allows autonomous and independent control of the tilting of the ring wing relative to the aircraft. The ring wing pod acts as both a nacelle to house the propulsion elements as well as a lifting surface when in wing-borne flight. The autonomous thrust vectoring ring wing pod also provides superior aircraft attitude control in wing-borne flight, thus negating the need for conventional surface controls.

Abstract: A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

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

Abstract: A tailsitter aircraft includes an airframe, a thrust array attached to the airframe and a flight control system. The thrust array includes propulsion assemblies configured to transition the airframe from a forward flight orientation to a VTOL orientation at a conversion rate for an approach to a target ground location in a forward flight-to-VTOL transition phase. The flight control system implements an adaptive transition system including a transition parameter monitoring module configured to monitor parameters including a ground speed and a distance to the target ground location. The adaptive transition system includes a transition adjustment determination module configured to adjust the conversion rate of the airframe from the forward flight orientation to the VTOL orientation based on the ground speed and the distance to the target ground location such that the airframe is vertically aligned with the target ground location in the VTOL orientation of the forward flight-to-VTOL transition phase.

Abstract: A system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprises: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

Abstract: A battery cell assembly, including a rolled cell formed from a first electrode and a second electrode rolled together about a longitudinal axis. The rolled cell includes a primary section in which the first electrode and the second electrode overlap in a radial direction from the longitudinal axis, and a first extension end extending from a first longitudinal end of the primary section and formed from a first edge section of the first electrode. The first edge section includes a first folded portion folded to contact an adjacent portion of the first edge section. The battery cell assembly further includes a first end cap coupled to the rolled cell and contacting the first folded portion.

Abstract: A multi-mode aircraft power-split-transmission system includes a rotational power input and a power-split transmission. The power-split transmission includes a sun gear, a planetary carrier, a ring gear, a first rotational power output, and a second rotational power output. The multi-mode aircraft power-split-transmission system also includes a first resistance device coupled to the first rotational power output and fixed to an airframe of the multi-mode aircraft and a second resistance device coupled to the second rotational power output and fixed to the airframe. Operation of the first resistance device causes power received from the rotational power input to be directed to the second rotational power output.

Abstract: A spar assembly has a spar having a tip comprising a most outboard portion of the spar, a root comprising a most inboard portion of the spar, a main section disposed inboard relative to the tip, and a middle section disposed inboard relative to the main section. The spar also has a transition section disposed between the main section and the middle section and the transition section has an outboard interface cross-sectional shape and an inboard cross-sectional shape that is different than the outboard interface cross-sectional shape.

Abstract: An exemplary pitch link centering tool includes a rod having a longitudinal axis, a front face, a rear face, a first rod end and a second rod end, the first rod end having a first aperture with a first rotational axis, the second rod end having a second aperture with a second rotational axis, a first connector coupled to the first rod end, the first connector having a first slot extending in a first radial direction relative to the longitudinal axis and a second connector coupled to the second rod end, the second connector having a second slot extending in a second radial direction relative to the longitudinal axis different from the first radial direction.

Abstract: A system for connecting two panels together. A recess is formed in the edge of one panel, and an insert is pressed into and held within the recess. The top of the insert includes holes for receiving epoxy, and epoxy conducting shafts and circuits formed on the outside of the insert assist in the encapsulation of the insert within the panel edge. The top of the insert includes an aperture formed such that a fastener can be received into a cavity formed in the recess and then driven to be secured into a fastener-receiving insert installed into the second panel.