Abstract: An exemplary spring-loaded link for an aircraft including a spring interposed between a first and a second rod, the spring, when compressed, urging the first rod and the second rod away from each other.

Abstract: A parasite aircraft for airborne deployment and retrieve includes a wing; a fuselage rotatably mounted to the wing; a dock disposed on top of the fuselage and configured to receive a maneuverable capture device of a carrier aircraft; a pair of tail members extending from the fuselage; and a plurality of landing gear mounted to the wing. A method of preparing a parasite aircraft for flight includes unfolding an end portion of a wing; unfolding an end portion of a tail member of the parasite aircraft; and rotating a fuselage of the parasite aircraft so that the fuselage is perpendicular to the wing. A method of preparing a parasite aircraft for storage includes rotating a fuselage of the parasite aircraft to be parallel with a wing of the parasite aircraft; folding an end portion of the wing; and folding an end portion of a tail member of the parasite aircraft.

Abstract: A ducted-rotor aircraft may include a fuselage and first and second ducts that are coupled to the fuselage at respective first and second locations. The first location may be on a first side of a fuselage of the aircraft and spaced from a nominal yaw axis of the aircraft. The second location may be on an opposed second side of the fuselage and spaced from the nominal yaw axis. Each duct may include a rotor that is disposed in an opening that extends through the duct. Each rotor may include a plurality of blades. Each duct may further include a control vane that is mounted aft of the plurality of blades and that is pivotable about a vane axis that is oriented toward the nominal yaw axis.

Abstract: A duct for a ducted-rotor aircraft includes a hub, a duct ring, and a plurality of stators that extend outward from the hub. The hub may be configured to support a motor. The duct ring defines a trailing edge. The duct ring is coupled to each of the plurality of stators such that all or substantially all of each of the plurality of stators is located aft of the trailing edge of the duct ring.

Abstract: A ducted-rotor aircraft includes a fuselage, one or more ducts, and a spindle that rotatably couples the one or more ducts to the fuselage. Each duct includes a hub that is configured to support a rotor, a plurality of stators that are coupled to the hub, a duct ring that is coupled to the plurality of stators, and a fitting that is coupled to a first stator of the plurality of stators. The fitting has a tubular collar that defines a first aperture that extends through the fitting. The collar is configured to receive a portion of the spindle. The first stator includes a rib that is spaced inward from the fitting and that defines a second aperture that is aligned with the first aperture and that is configured to receive an end of the spindle.

Abstract: A ducted-rotor aircraft includes a fuselage, first and second ducts, and a spindle that is coupled to the fuselage. Each duct includes a rotor having a plurality of blades. The first and second ducts are coupled to opposed ends of the spindle. The spindle is rotatably coupled to the fuselage with first and second bearings. The first bearing is configured to react to radial loads and the second bearing is configured to react to both radial and axial loads. The spindle includes a shaft, first and second fittings secured to opposed ends of the shaft, and first and second attachment interfaces that are attachable to the first and second ducts. The attachment interfaces may be integral with the fittings. Alternatively, the fittings may be configured to be secured to the attachment interfaces with fasteners.

Abstract: A duct for a ducted-rotor aircraft includes a hub, a duct ring, and a plurality of stators that extend outward from the hub. The duct ring defines a trailing edge. The duct includes one or more fittings, such as a system of fittings. Each fitting has a body that defines a first attachment interface that is configured to couple to structure of the duct ring and a second attachment interface that is configured to couple to one of the plurality of stators. The first and second attachment interfaces are spaced from each other such that when the fittings are coupled to the duct ring and the plurality of stators, all or substantially all of each of the plurality of stators are located aft of the trailing edge of the duct ring.

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: An aircraft including a nacelle disposed at a fixed location relative a wing member; a proprotor housing coupled to the nacelle, the proprotor housing configured to selectively rotate between a horizontal orientation and a non-horizontal orientation; a door pivotably coupled to the proprotor housing; and a linkage to connect the door and the nacelle, the linkage configured to move with the door from a closed position when the proprotor housing is in a horizontal orientation to an open position when the proprotor housing is in a non-horizontal orientation. In some embodiments, there can be a hinge member for hingedly coupling the door to the proprotor and/or nacelle. In other embodiments, the door includes a flexure portion. In some embodiments, the nacelle includes a plurality of doors. In other embodiments, proprotor includes a forward portion and a stationary aft portion; wherein the forward portion is configured to selectively pivot.

Abstract: A method for selectively modulating bleed air used for cooling a downstream turbine section in a gas turbine engine. The method including: measuring an engine and/or aircraft performance parameter by an engine sensor device; comparing the engine and/or aircraft performance parameter to a performance threshold; determining a bleed trigger condition, if the engine and/or aircraft performance parameter crosses the performance threshold; determining a non-cooling condition, if the engine and/or aircraft performance parameter is below the performance threshold; actuating a flow control valve to an open position, in response to the bleed trigger condition, so that bleed air is extracted from the compressor section and flowed to the downstream turbine section; and terminating, in response to the non-cooling condition, the flow of the bleed air to the downstream turbine section of the engine by actuating the flow control valve to a closed position.

Abstract: A system for securing a bearing to a shaft includes a shaft having a raised portion extending radially outward from the shaft. The raised portion includes a first angled face on a first side of the raised portion and a second angled face on a second side of the raised portion. The bearing includes an outer race comprising a bearing surface on an inner face of the outer race, an inner race comprising a bearing surface on an outer face of the inner race and a third angled face on an inner face of the inner race that is configured to mate with the first angled face, and a plurality of rollers disposed between the inner and outer races.

Abstract: An open mold for producing components made of a moldable material such as layered composite materials is made from an additive manufacturing technology. The mold includes at least two compatible mold segments which precisely interlock with and abut against each other. The mold thereby made may be larger than the limited printing area of an additive manufacturing machine.

Abstract: An apparatus is described and in one embodiment includes a first portion comprising an inner diameter, a first outer diameter, and a first length and a second portion, wherein the first portion and the second portion are integrally connected together, the second portion comprising the inner diameter, at least one second outer diameter, and a second length. The embodiment further includes a flange comprising a contact surface, wherein the inner diameter of the first portion and the second portion provides a hollow pathway through the apparatus.

Abstract: A device to verify tail rotor cross-head positioning is disclosed. The device comprises a first portion and a second portion. The second portion may be adjoined to the first portion and comprises maximum and minimum surfaces configured to determine whether a yoke-measuring surface of a tail rotor yoke may be positioned between respective geometric planes of the maximum and minimum surfaces.

Abstract: Various implementation described herein are directed to a method for identifying a blockage in a pitot-static system. A pressure signal is received. Pressure fluctuations in the pressure signal are identified. A determination is made as to whether a blockage has occurred in the pitot-static system based on the identified pressure fluctuations.

Abstract: A bonded part includes a first surface facing toward a second surface, and a cured adhesive between the first and second surfaces defining a bond line. A surface structure on the first surface is within the bond line and has surface protrusions arranged in a pattern. Each surface protrusion protrudes outwardly from a first end at the first surface to a second end adjacent to the second surface. A thickness of the surface protrusions is substantially equal to the thickness of the bond line. The cured adhesive extends around the surface protrusions. The thickness of the bond line between the first and second surfaces is substantially constant along the bond line, and is greater than a thickness of the cured adhesive between the second ends of the protrusions and the second surface.

Abstract: A system and method for preventing a maximum asymmetric condition between pylon tilt angles due to a degraded pylon in a fly-by-wire tiltrotor aircraft during transitions between airplane mode and helicopter mode includes a conversion system for imparting movement on a right and left pylon. A flight control computer is operatively connected to a set of transducers for measuring pylon angles. The flight control computer is further connected to a set of actuators which are attached to each pylon. The flight control computer receives flight dynamics input from the set of transducers and/or the pilot and sends pylon command to the set of actuators. The conversion system measures the difference between the pylon angles during the transition and provides a pylon command adjustment if the difference exceeds a preset threshold.

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: An anti-torque assembly for a helicopter includes a plurality of fans pivotably mountable to a tail boom. The fans have fan blades rotatable about a fan axis. One or more of the fans is pivotable relative to the tail boom to a first configuration. The fan axes in the first configuration have an upright orientation and the fans are operable to one or both of pitch and roll the helicopter. Different fans are operable to generate thrust to provide anti-torque to the helicopter. A method of providing anti-torque and method of changing an attitude of a helicopter are also provided.

Abstract: An exemplary liquid tank level measurement system includes a tank having a wall, an accelerometer attached to the wall and configured to measure a vibration in the wall, and an instrument electronically connected to the accelerometer, the instrument configured to communicate a liquid level condition responsive to a vibration measurement received from the accelerometer.