An example valve includes a housing, a sleeve disposed within the housing and having a first end and a second end opposite the first end, and the sleeve includes a plurality of sleeve protrusions at the first end and a plurality of fluid flow channels are formed between adjacent sleeve protrusions, a seal carrier disposed within the sleeve and having a carrier protrusion that extends from the second end of the sleeve and abuts against an interior surface of the housing, and an end cap mounted to the housing such that the plurality of sleeve protrusions abut against the end cap.

A nose-wheel steering system is disclosed. In various embodiments, the system includes an actuator; a strut; and a gearing mechanism operably coupling the actuator to the strut, the gearing mechanism including a steering collar attached to the strut, and idler gear engaged with the actuator and a pinion having a first gear engaged with the idler gear and a second gear engaged with the steering collar.

A nose-wheel steering system is disclosed. In various embodiments, the system includes an actuator; a strut; and a gearing mechanism operably coupling the actuator to the strut, the gearing mechanism including a steering collar attached to the strut, and idler gear engaged with the actuator and a pinion having a first gear engaged with the idler gear and a second gear engaged with the steering collar.

The present disclosure relates to unmanned aerial vehicles (“UAVs”), systems, and methods for efficiently and safely landing while improving flight performance. In particular, the disclosure incudes a light-weight, gravity-fed, self-deploying landing gear assembly that aligns to the direction of the runway upon landing. For example, the landing gear assembly can include a pin switch and a tear-through barrier that releases and deploys the landing gear assembly. Additionally, the landing gear assembly can include castering wheels that rotate (i.e., swivel) while the UAV is in flight. Furthermore, the landing gear assembly can include friction-disks to reduce the rotation of the castering wheels when the landing gear assembly contacts the ground and receives the weight of the UAV. Moreover, the landing gear assembly can detect that the UAV has landed and can signal the UAV to initiate a roll stop mechanism.

A shimmy damper for centering a landing gear includes a cap and a housing. The shimmy damper further includes a damper shaft extending from the cap to the housing. The shimmy damper further includes a plurality of magnets configured to exert an opposing force on the cap and the housing via the damper shaft, providing a centering mechanism of the damper shaft within the housing. This centering action in turn provides for the centering of the landing gear during flight.

An aircraft undercarriage having a sliding rod slidably mounted in a strut-leg, and a scissors linkage (4) having one branch (4a) hinged to the strut-leg or to a turning element of a control for steering the sliding rod mounted to turn in the strut-leg, and one branch (4b) hinged to the sliding rod, the branches being hinged to each other by a pivot pin (12), the undercarriage being fitted with a shimmy-attenuator device (10a, 10b) placed on the pivot pin of the shimmy-attenuator, the attenuator device including threshold resilient return means generating a force returning the branches towards a rest position, and at least damping means generating a damping force when the branches move axially along the pivot pin. The attenuator device comprises two modules (10a, 10b) placed on either side of the scissors linkage in order to co-operate with the pivot pin, each of the modules performing at least one of the damping function and the threshold resilient return function.

A steering apparatus may comprise a steering collar, a first linear actuator, a first drive gear, a crankshaft, and a sun gear, wherein the sun gear is disposed within the collar, wherein the first drive gear is fixed to the crankshaft and coupled to the sun gear such that the collar rotates about the sun gear in response to rotation of the crankshaft, wherein the first linear actuator is coupled between the crankshaft and the collar.

An example aircraft includes (i) a landing gear having a chassis, an axle, and wheels mounted to ends of the axle; (ii) a hydraulic actuator including a cylinder, a first piston coupled to the chassis, and a second piston coupled to the axle; and (iii) a directional control valve including: inlet ports configured to be fluidly coupled to a source of pressurized fluid, tank ports configured to be fluidly coupled to a tank, and workports configured to be fluidly coupled to the hydraulic actuator.

To provide a safety device that, when a crosswind is present, allows an aircraft to more safely land on a runway in an airport. This safety device 10 for landing in a crosswind is designed for landing of an aircraft 1 on a runway 3 in a crosswind across the runway 3, and provided with a control unit 14 for controlling, when the nose cone 1T of the fuselage 8 of the aircraft 1 is directed windward, the orientation of the wheels of the aircraft 1 such that the wheels are oriented in the direction of travel of the aircraft 1.

A landing-gear assembly (1) for an aircraft, the landing-gear assembly comprising: an axle shaft (2); a leg (3) presenting a first portion (3a) carrying said axle shaft (2) and a second portion (3b) connected to a carrier structure of the aircraft; a main damper (5); and a first secondary damper (6a) distinct from the main damper (5). The first secondary damper (6a) is carried by the axle shaft (2) and comprises: an inertial mass (M); and connection means (7a) between the inertial mass (M) and the axle shaft (2) damping movements of the inertial mass (M) along a first axis (X1) of movement of the inertial mass (M) relative to the axle shaft (2), said first axis of movement (X1) extending in a plane (P) perpendicular to said steering axis (Z).