A blade pitch control assembly includes a pitch control actuator having a coarse actuator chamber having a coarse chamber area and a fine actuator chamber having a fine chamber area. The coarse chamber area is biased to a feather position. The assembly also includes a primary pitch control valve configured to control the flow of pressurised fluid to the coarse actuator chamber and the fine actuator chamber, respectively via a coarse fluid line and a fine fluid line. The assembly further includes a hydraulic protection system located between the actuator and the primary pitch control valve, configured to bypass the primary pitch actuator in response to a trigger. The hydraulic protection system has a hydraulic protection system valve located between the fluid lines and when activated fluidly connects the fluid lines to balance fluid pressure between the coarse chamber and the fine chamber.

A mechanism for folding a rotor blade that is rotatably coupled to a blade cuff about a blade-fold axis between an extended position and a folded position. The mechanism includes a swash plate configured to translate relative to a mast, a pitch link rotatably coupled to the swash plate, a pitch horn rotatably coupled to the pitch link, a crank coupled to the pitch horn, and a link rotatably coupled to the crank and rotatably coupled to the rotor blade. The pitch horn and the crank being configured to commonly rotate relative to the blade cuff about a crank axis in response to translation of the swash plate, wherein the crank axis passes through the blade cuff.

A mechanism for folding a rotor blade that is rotatably coupled to a blade cuff about a blade-fold axis between an extended position and a folded position. The mechanism includes a swash plate configured to translate relative to a mast, a pitch link rotatably coupled to the swash plate, a pitch horn rotatably coupled to the pitch link, a crank coupled to the pitch horn, and a link rotatably coupled to the crank and rotatably coupled to the rotor blade. The pitch horn and the crank being configured to commonly rotate relative to the blade cuff about a crank axis in response to translation of the swash plate, wherein the crank axis passes through the blade cuff.

A bearing system includes an inboard bearing assembly and an outboard bearing assembly. The inboard bearing assembly includes an inboard fitting and an inboard race. The inboard fitting includes a plate with a convex mating surface and a first aperture formed through the plate for receiving a blade root of a rotor blade. The inboard race comprising a concave mating surface configured to receive the convex mating surface a second aperture formed the inboard race. The outboard bearing assembly includes an outboard bearing assembly comprising an outboard fitting having an aperture formed therethrough for receiving the blade root of the rotor blade.

A yoke plate arrangement may comprise a yoke plate, a wear plate comprising a wear surface and a contact surface, wherein a post extends from the contact surface, and a yoke plate ear extending from the yoke plate in a radial direction, wherein a first aperture is disposed in the yoke plate ear, the post located at least partially within the first aperture, the contact surface being in contact with the yoke plate ear. The yoke plate arrangement may further comprise a retaining feature for coupling the wear plate to the yoke plate. The wear surface may be for engaging a trunnion bearing.

A yoke plate arrangement may comprise a yoke plate, a wear plate comprising a wear surface and a contact surface, wherein a post extends from the contact surface, and a yoke plate ear extending from the yoke plate in a radial direction, wherein a first aperture is disposed in the yoke plate ear, the post located at least partially within the first aperture, the contact surface being in contact with the yoke plate ear. The yoke plate arrangement may further comprise a retaining feature for coupling the wear plate to the yoke plate. The wear surface may be for engaging a trunnion bearing.

A rotor blade pitch control system (15) comprising a rotor blade (19a, 19b, 19c, 19d) rotatable about both a central axis (20) and a pitch axis (24a, 24b, 24c, 24d), a pitch drive rotor (32a, 32b, 32c, 32d) rotatable about the central axis independently of rotation of the rotor blade about the central axis, a pitch follower (40a, 40b, 40c, 40d) rotatable relative to the pitch drive rotor, the pitch drive rotor and the pitch follower having an eccentric axis (33a, 33b, 33c, 33d), a linkage (50a, 50b, 50c, 50d) between the pitch follower and the rotor blade configured such that the pitch follower rotates with rotation of the rotor blade about the central axis, the pitch drive rotor, the pitch follower and the linkage configured such that the pitch drive rotor may be driven to control an angular displacement of the pitch drive rotor relative to the pitch follower about the central axis and thereby control the pitch of the rotor blade about the pitch axis.

A bearing system includes an inboard bearing assembly and an outboard bearing assembly. The inboard bearing assembly includes an inboard fitting and an inboard race. The inboard fitting includes a plate with a convex mating surface and a first aperture formed through the plate for receiving a blade root of a rotor blade. The inboard race comprising a concave mating surface configured to receive the convex mating surface a second aperture formed the inboard race. The outboard bearing assembly includes an outboard bearing assembly comprising an outboard fitting having an aperture formed therethrough for receiving the blade root of the rotor blade.

A fan for providing thrust including at least one blade, a hub adapted to carry the at least one blade, a hub motor adapted to rotate the hub 360 degrees about a first axis extending perpendicular to the at least one blade, a first mount adapted to carry the hub, and a first mount motor adapted to rotate the hub 360 degrees about a second axis perpendicular to the first axis and extending through the first mount first and second side securing points. The first mount may include a first mount first side securing point adapted to pivotally carry the hub, and a first mount second side securing point adapted to pivotally carry the hub.

A fan for providing thrust including at least one blade, a hub adapted to carry the at least one blade, a hub motor adapted to rotate the hub 360 degrees about a first axis extending perpendicular to the at least one blade, a first mount adapted to carry the hub, and a first mount motor adapted to rotate the hub 360 degrees about a second axis perpendicular to the first axis and extending through the first mount first and second side securing points. The first mount may include a first mount first side securing point adapted to pivotally carry the hub, and a first mount second side securing point adapted to pivotally carry the hub.