The landing gear systems, methods and apparatuses disclosed herein may comprise a shrink pump and a shrink valve that are capable of shrinking a landing gear by up to 40% of its available stroke, or more depending on the air spring configuration. The shrink pump may be configured to pump fluid (e.g., a hydraulic fluid) between an oil chamber, where hydraulic fluid is likely present and a shrink chamber to shrink the landing gear. Moreover, the shrink pump and shrink valve may be part of a strut shrink system.

The emergency landing gear actuator for aircraft utilizes a pair of airbags for rapid emergency deployment of landing gear when the conventional hydraulic actuator fails. In the retracted position, the at least one wheel of the landing gear is stored in a first cavity formed in the lower portion of the wing. The shock strut and the side strut are stored in an adjacent second cavity formed in the lower portion of the wing. First and second airbags are respectively mounted in the first and second cavities. The first airbag and the second airbag are each selectively inflatable for emergency deployment of the at least one wheel, the shock strut and the side strut. When the hydraulic actuator fails to deploy the landing gear, the first and second airbags are inflated, forcing the shock strut to rotate and position the at least one wheel in its deployed position.

The emergency landing gear actuator for aircraft utilizes a pair of airbags for rapid emergency deployment of landing gear when the conventional hydraulic actuator fails. In the retracted position, the at least one wheel of the landing gear is stored in a first cavity formed in the lower portion of the wing. The shock strut and the side strut are stored in an adjacent second cavity formed in the lower portion of the wing. First and second airbags are respectively mounted in the first and second cavities. The first airbag and the second airbag are each selectively inflatable for emergency deployment of the at least one wheel, the shock strut and the side strut. When the hydraulic actuator fails to deploy the landing gear, the first and second airbags are inflated, forcing the shock strut to rotate and position the at least one wheel in its deployed position.

A hydraulic strut assembly, for use in a semi-levered landing gear in an aircraft, comprising an actuator and a manifold associated with the actuator. The actuator comprises a housing, a first piston, a second piston, and a third piston. The first piston is positioned between outer and inner cylindrical structures of the housing. The outer and inner cylindrical structures and first piston form an outer chamber that receives a first fluid. The inner cylindrical structure, the first piston, and the second piston, which is nested within the first piston, form an inner chamber, which holds a second fluid comprising a gas. A volume of the inner chamber changes when at least one of the first and second pistons moves. The third piston is positioned between the outer cylindrical structure and the first piston. The first, second, and third pistons move in a direction parallel to an axis through the housing.

A hydraulic strut assembly, for use in a semi-levered landing gear in an aircraft, comprising an actuator and a manifold associated with the actuator. The actuator comprises a housing, a first piston, a second piston, and a third piston. The first piston is positioned between outer and inner cylindrical structures of the housing. The outer and inner cylindrical structures and first piston form an outer chamber that receives a first fluid. The inner cylindrical structure, the first piston, and the second piston, which is nested within the first piston, form an inner chamber, which holds a second fluid comprising a gas. A volume of the inner chamber changes when at least one of the first and second pistons moves. The third piston is positioned between the outer cylindrical structure and the first piston. The first, second, and third pistons move in a direction parallel to an axis through the housing.

A poppet of a check valve includes a base, a shaft extending from the base, and a sealing head coupled to the shaft and extended away from the base by the shaft. A flow channel is defined between the base, the shaft, and the sealing head. The base includes a plurality of holes.

A poppet of a check valve includes a base, a shaft extending from the base, and a sealing head coupled to the shaft and extended away from the base by the shaft. A flow channel is defined between the base, the shaft, and the sealing head. The base includes a plurality of holes.

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.

The invention relates to a surfing arrangement (3) for mounting to underneath an aircraft (1), comprising at least a tank of a water collecting system (10), which arrangement (3) is configured for providing a gliding surface (7) on which said aircraft (1) may surf on water when having a moving speed higher than a predetermined value. The arrangement (3) comprises an elongated body (9), underneath which elongated body (9) the gliding surface (7) is situated, wherein the elongated body (9) is connectable to underneath an aircraft (1) by means of a linkage arm arrangement (23) arranged to a coupling element (25) configured to be coupled to the aircraft (1). The linkage arm arrangement (23) is, when the arrangement (3) is coupled to an aircraft (1), operational to vertically move the elongated body (9) between a raised position, in which raised position the gliding surface (7) is positioned above a lowermost contact point of a piece of a landing gear (5), and a lower position, in which lower position the gliding surface (7) is positioned underneath said lowermost contact point of the piece of said landing gear (5). Said movement of the elongated body (9) being selectively operational during flight of the aircraft (1). The invention further relates to an aircraft (1) comprising such a surfing arrangement (3).

An aircraft hydraulic actuation system for retracting an aircraft landing gear. The actuation system includes a supply line arranged to carry hydraulic fluid pressurized by a pump, a return line arranged to return hydraulic fluid to a reservoir, and a hydraulic actuator 128. In a first mode of operation, a first chamber 130 of the actuator 128 is supplied with pressurized hydraulic fluid from the supply line such that a piston 134 is moved in a first direction so as to move a load such as a landing gear. In a second mode of operation, the first chamber 130 is taken out of fluid communication with the supply line and a second chamber 132 is in fluid communication with the return line, such that the piston 134 is able to be moved under the influence of the load, for example when the landing gear extends under gravity.