Abstract: A yoke split into separate, individual yoke arms permit rotor blade fold about inboard yoke arm bolts in a rotor blade assembly for rotorcraft and tiltrotor aircraft. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: An intentionally activated frangible bonding system comprises a frangible adhesive, adhesive primer, composite material matrix, and/or the like, having a polydispersion of at least one additive spread throughout the frangible bonding material. The additive degrades a bond provided by the frangible bonding material, upon application of a specific energy to the frangible bonding material. An energy emitter is configured to selectively direct the specific energy toward a structure or assembly comprising components bonded by the frangible bonding material to degrade the frangible bonding material bonding the components for disassembly.

Abstract: A blade for an aircraft rotor has a trailing-edge tab, the tab being movable between a stowed position, in which substantially all of the tab is located within the blade, and a deployed position, in which at least a portion of the tab extends from a trailing edge of the blade. At least one actuator system is selectively operable to cause movement of the tab between the stowed position and the deployed position for changing a chord length of the blade.

Abstract: A tiltrotor aircraft includes a fuselage, a wing member extending from the fuselage, an engine disposed relative to the wing member and a proprotor mechanically coupled to the engine. The proprotor includes a plurality of proprotor blade assemblies each including a spar and a sheath extending spanwise along the spar forming the leading edge of the proprotor blade assembly. The spar has a root section, a main section and a tip section. The spar has a generally oval cross section at radial stations along the main section and a first edge having a structural bias relative to a generally oppositely disposed second edge at the radial stations along the main section.

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: A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode. The proprotor system includes a yoke having a plurality of blade arms with inboard pockets. A centrifugal force and shear bearing assembly is disposed in each of the inboard pockets of the yoke. Each of a plurality of proprotor blades is coupled to the yoke by one of the bearing assemblies such that each proprotor blade has a pitch change degree of freedom about a pitch change axis and a tilting degree of freedom about a focal point. Each bearing assembly includes a centrifugal force bearing coupled to the yoke, a shear bearing coupled to the yoke and an inboard beam coupled between the centrifugal force bearing and the shear bearing. Each inboard beam is coupled to a respective proprotor blade.

Abstract: The present invention includes a balancing system that includes a weight box, mounted substantially within the rotor-blade spar, flush with a rotor-blade spar outer surface, operably accessible from a rotor-blade tip, and retained within the rotor-blade spar by a weight-box retention pin, one or more weight-box contact surfaces bonded to a rotor-blade-spar inner surface, or a weight-box lip providing a bearing contact with an edge of a spar rotor-blade spar cutout; and a weight package attached to the weight box, the weight package including a weight-box cover, two or more weight guide-rods attached to the weight-box cover, wherein one of the two or more weight guide-rods is positioned forward of a pitch change axis or center of twist and wherein one of the two weight guide-rods is positioned aft of the pitch change axis or center of twist, and one or more balance weights mounted on the weight guide-rods.

Abstract: The present invention includes a first barrier layer configured to cover a leading edge of the blade or wing; one or more electrical bus bars disposed on the first barrier layer proximate to and substantially parallel with the leading edge; a ground bus bar disposed on the first barrier layer proximate to and substantially parallel with the leading edge; a second barrier layer disposed over the one or more electrical bus bars and the ground bus bar; one or more heating elements disposed on the second barrier layer, and each heating element electrically connected to one of the electrical bus bars and to the ground bus bar; and a third barrier layer disposed over the one or more heating elements.

Abstract: A tiltrotor aircraft includes a fuselage, a wing member extending from the fuselage, an engine disposed relative to the wing member, a rotor hub assembly mechanically coupled to the engine and a plurality of proprotor blade assemblies rotatably mounted to the rotor hub assembly and operable for beamwise folding relative thereto. The proprotor blade assemblies each including a spar and a sheath extending spanwise along a leading edge of the spar. The spar has a root section, a main section and a tip section. The spar has a generally oval cross section at radial stations along the main section of the spar with the root section of the spar forming an integral tang assembly operable for coupling the spar to the rotor hub assembly.

Abstract: A weight system for a rotor blade includes a weight box open in an outboard direction, a weight guide rod connected to the weight box, the weight guide rod extending in a spanwise direction through an interior of the weight box, and a span balance weight disposed within the weight box, the span balance weight being captured between the weight guide rod and the weight box.

Abstract: A tiltrotor aircraft includes a fuselage, a wing member extending from the fuselage, an engine disposed relative to the wing member and a proprotor mechanically coupled to the engine. The proprotor includes a plurality of proprotor blade assemblies each including a spar and a sheath extending spanwise along the spar forming the leading edge of the proprotor blade assembly. The spar has a root section, a main section and a tip section. The spar has a generally oval cross section at radial stations along the main section and a first edge having a structural bias relative to a generally oppositely disposed second edge at the radial stations along the main section.

Abstract: A tiltrotor aircraft includes a fuselage, a wing member extending from the fuselage, an engine disposed relative to the wing member, a rotor hub assembly mechanically coupled to the engine and a plurality of proprotor blade assemblies rotatably mounted to the rotor hub assembly and operable for beamwise folding relative thereto. The proprotor blade assemblies each including a spar and a sheath extending spanwise along a leading edge of the spar. The spar has a root section, a main section and a tip section. The spar has a generally oval cross section at radial stations along the main section of the spar with the root section of the spar forming an integral tang assembly operable for coupling the spar to the rotor hub assembly.