Abstract: A variable-sweep wing for a tiltrotor aircraft includes a fuselage link coupled to the fuselage and a pylon link coupled to a pylon. A wing airframe has a root end pivotably coupled to the fuselage link and a tip end pivotably coupled to the pylon link. A driveshaft is coupled between the fuselage link and the pylon link and is positioned within the wing airframe. The driveshaft is operable to transmit torque from the main gearbox to a proprotor gearbox. A crank is coupled between the fuselage link and the pylon link and is positioned within the wing airframe. The fuselage link, the pylon link, the driveshaft and the crank form a linkage such that pivoting the crank relative to the fuselage link causes the wing airframe to shift between a substantially straight wing configuration for low-speed forward flight and a swept wing configuration for high-speed forward flight.

Abstract: An embodiment is a system including an external passenger seating unit comprising at least one seat; and a translation mechanism for translating the external passenger seating unit between a first position in which the external passenger seating unit is stowed in a payload bay of an aircraft and a second position in which the external passenger seating unit is deployed external to the aircraft for accommodating at least one passenger.

Abstract: Embodiments are directed to systems and methods for deploying an outboard rotor blade of proprotor pylon to act as an extended lifting surface. Blade control actuators may provide primary rotor flight control as well as providing fold linkage actuation when fold locks are disengaged. During cruise flight, the blade control actuator may provide feathering inputs to the extended rotor blade, wherein the amplitude and frequency of feathering inputs are tuned to mitigate undesirable wing and fuselage dynamic modes thereby enhancing aircraft stability. The deployed rotor blades also improve the total lifting area of the aircraft, which may increase aircraft range and efficiency.

Abstract: An elastomeric bearing assembly has a housing, a centrifugal force bearing axially captured relative to the housing, and a sliding cap disposed between the housing and the centrifugal force bearing.

Abstract: A stowable lift rotor is coupled to an airframe of a VTOL aircraft. The VTOL aircraft is convertible between a VTOL flight mode and a forward flight mode. The stowable lift rotor includes a lift arm. The proximal end of the lift arm is coupled to the airframe of the VTOL aircraft. The stowable lift rotor also includes a rotor assembly including rotor blades coupled to the distal end of the lift arm. The lift arm is movable between various positions including an extended position in the VTOL flight mode, a stowed position in the forward flight mode and intermediate positions therebetween such that the distance between the rotor assembly and the airframe is greater in the extended position than in the stowed position.

Abstract: A stowable lift rotor is coupled to an airframe of a VTOL aircraft. The VTOL aircraft is convertible between a VTOL flight mode and a forward flight mode. The stowable lift rotor includes a lift arm. The proximal end of the lift arm is coupled to the airframe of the VTOL aircraft. The stowable lift rotor also includes a rotor assembly including rotor blades coupled to the distal end of the lift arm. The lift arm is movable between various positions including an extended position in the VTOL flight mode, a stowed position in the forward flight mode and intermediate positions therebetween such that the distance between the rotor assembly and the airframe is greater in the extended position than in the stowed position.

Abstract: An exemplary clamp system for securing a proprotor blade in a stowed position includes a clamp having a pair of opposing pads operable between an open position to receive a portion of a proprotor blade between the pair of opposing pads and a closed position to grip the portion of the proprotor blade with the pair of opposing pads and a rotary actuator in connection with the clamp to operate the clamp between the open and the closed position.

Abstract: Embodiments are directed to systems and methods for creating a tubular composite structure. In one embodiment, a device comprises multiple layers of cured composite fabric bonded together to form a tubular composite structure, wherein alternating groups of the multiple layers comprise on-axis fabric and off-axis fabric. The tubular composite structure may form a spar for an aerodynamic component. The composite fabric may comprise one or more of carbon, fiberglass, or other composite materials, or a combination of materials. One or more stacks of the fabric wrap completely around the tubular composite structure, and other stacks of fabric may not wrap completely around the tubular composite structure.

Abstract: An embodiment is a system including an external passenger seating unit comprising at least one seat; and a translation mechanism for translating the external passenger seating unit between a first position in which the external passenger seating unit is stowed in a payload bay of an aircraft and a second position in which the external passenger seating unit is deployed external to the aircraft for accommodating at least one passenger.

Abstract: Embodiments are directed to a selectable drive system that allows a rotor gearbox to send torque to a proprotor assembly and/or through a multiplier planetary gear set to a pylon-mounted ducted fan thrust unit. The rotor drive system may be a stop-fold system in which rotor blades can be folded when not rotating. This allows a normally idle lift engine to provide additional aircraft thrust during cruise where an aircraft is typically using only a dedicated thrust engine for high speed flight. An inline engage/disengage actuator or “shift fork” on the rotor gearbox is used to select the torque-output direction. The multiplier planetary gear set increases the output RPM that is received from the rotor gearbox and that is applied to the thrust fan unit.

Abstract: An aircraft includes a pylon rotatable relative to a wing, a proprotor assembly carried by the pylon, the proprotor assembly have a proprotor blade that is foldable to a stowed position extending substantially parallel to the pylon, and a fluidic clamp positioned with the pylon and configured to grip the proprotor blade when in the stowed position, the fluidic clamp including a first inflatable bladder positioned on a first side of an opening for receiving a portion of a proprotor blade and a pressurized fluid source in fluid connection with the first inflatable bladder.

Abstract: A rotor assembly for use in an aircraft comprising has a rotor hub, a spinner structure comprising a spinner opening, and a rotor blade received through the spinner opening. The rotor blade has a rotor root located proximate to the rotor hub. The rotor assembly also has a motive fairing face that at least partially rests along the rotor hub.

Abstract: An advancing blade concept rotorcraft includes an airframe and a pylon assembly subject to vibration. The pylon assembly includes a dual rotor system having coaxially disposed top and bottom rotor assemblies that counter rotate relative to one another. The advancing blade concept rotorcraft includes a vibration isolation system including at least one pylon link coupled to the airframe and the pylon assembly. The pylon link includes a Liquid Inertia Vibration Eliminator unit operable to reduce transmission of the pylon assembly vibration to the airframe. The advancing blade concept rotorcraft includes active force generators adjacent to the pylon assembly. The active force generators include a first active force generator producing a force in a first direction and a second active force generator producing a force in a second direction to counteract multidirectional oscillations of the pylon assembly, thereby reducing vibration of the advancing blade concept rotorcraft.

Abstract: Embodiments are directed to a selectable drive system that allows a rotor gearbox to send torque to a proprotor assembly and/or through a multiplier planetary gear set to a pylon-mounted ducted fan thrust unit. The rotor drive system may be a stop-fold system in which rotor blades can be folded when not rotating. This allows a normally idle lift engine to provide additional aircraft thrust during cruise where an aircraft is typically using only a dedicated thrust engine for high speed flight. An inline engage/disengage actuator or “shift fork” on the rotor gearbox is used to select the torque-output direction. The multiplier planetary gear set increases the output RPM that is received from the rotor gearbox and that is applied to the thrust fan unit.

Abstract: An exemplary proprotor blade assembly includes a structural skin extending spanwise from a root to a tip and along a chord from leading edge to a trailing edge and a structural core positioned inside of the structural skin, the structural skin comprising hex-shaped structures oriented normal to the structural skin.

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: Systems and methods of operating a tiltrotor aircraft include providing the tiltrotor with a plurality of rotatable pylon assemblies. Each pylon assembly includes a rotor system having a plurality of rotor blades operatively coupled to a rotor mast and selectively rotatable in response to rotation of the rotor mast, a swashplate assembly operatively coupled to the plurality of rotor blades, a plurality of swashplate actuators operatively coupled to the swashplate assembly and selectively extendable and retractable to control the position and the orientation of the swashplate assembly, and a swashplate augmenting system. The swashplate augmenting system is selectively operable to cause axial translation of the swashplate actuators and swashplate assembly to augment the travel of the swashplate actuators in order to fold the plurality of rotor blades for operating the tiltrotor aircraft in an airplane forward flight mode.

Abstract: Embodiments are directed to systems and methods for deploying an outboard rotor blade of proprotor pylon to act as an extended lifting surface. Blade control actuators may provide primary rotor flight control as well as providing fold linkage actuation when fold locks are disengaged. During cruise flight, the blade control actuator may provide feathering inputs to the extended rotor blade, wherein the amplitude and frequency of feathering inputs are tuned to mitigate undesirable wing and fuselage dynamic modes thereby enhancing aircraft stability. The deployed rotor blades also improve the total lifting area of the aircraft, which may increase aircraft range and efficiency.

Abstract: A tiltrotor aircraft having a VTOL flight mode, a forward flight mode and a storage mode includes a fuselage having a wing rotatably mounted thereto. The wing has an orientation generally perpendicular to the fuselage, in the flight modes, and an orientation generally parallel to the fuselage, in the storage mode. First and second pylon assemblies are positioned proximate outboard ends of the wing. First and second mast assemblies are respectively rotatable relative to the first and second pylon assemblies and have generally vertical orientations, in the VTOL flight mode, and generally horizontal orientations, in the forward flight mode and the storage mode. First and second proprotor assemblies are respectively rotatable relative to the first and second mast assemblies. Each proprotor assembly includes a plurality of rotor blades and has a radially extended orientation, in the flight modes, and a stowed orientation, in the storage mode.

Abstract: Embodiments are directed to an aerodynamic spinner fairing having a sidewall and one or more airflow intakes in the sidewall. The airflow intakes are closed during a first phase of flight and open during a second phase of flight. The first phase of flight may be an airplane mode for a tiltrotor aircraft, and the second phase of flight may be a helicopter mode for the tiltrotor aircraft. The airflow intakes may comprise an opening in the sidewall, and a door that is configured to move between a first position covering the opening and a second position exposing the opening to external airflow. An actuator coupled to the door may operate to move the door between the first position and the second position. One or more guide vanes within the aerodynamic spinner fairing may be configured to direct air received via the airflow intakes to provide convection cooling.