The Boeing Company

Harry C Ralph

Ian Robert Bennett

Gerhard E Seidel

Donald L Grande

An aircraft landing gear brake arrangement wherein a landing gear stub axle and brake pressure plate are integrated. Each of the integrated assemblies is attached to a support fitting which pivots on the truck axle thereby causing the torque links to be unaffected by steering operations.

Aircraft landing gear having axle to brake plate integration

A main landing gear system which employs Ackermann type steering utilizing kingpins and tierods wherein a plurality of paired wheels are employed and wherein each truck axle is adapted for independent steering. Electronic control means along with hydraulic directional valve means are utilized.

Main landing gear having independent steering of each axle on multiple

A main landing gear system which employs Ackermann type steering utilizing kingpins and tierods wherein a plurality of paired wheels are employed and wherein each truck axle is adapted for independent steering. Electronic control means along with hydraulic directional valve means are utilized. A main landing gear having single wheel or king pin steering. Pivot pin tilting is utilized in truck type main landing gear, e.g. where a truck axle is adapted for independent steering or where single wheel or king pin steering is utilized.

Main landing gear having tilting of main gear pivot pins

Landing gear (10) for an airplane including an elongate strut (12) having a first end and a second end longitudinally spaced therefrom. The first end of the strut being pivotally attached to the airplane for pivotal movement of the strut between an extended position for taxiing and landing of the airplane and a retracted position for stowage of the landing gear within a landing gear bay. The landing gear assembly also includes elongate first and second hub assemblies (70) and (72) each having first and second ends. Landing wheels (20) and (22) are journaled to each of the second ends of the hub assemblies. The first ends of the hub assemblies are attached to the second end of the strut for swinging movement thereof between an unsplayed position, wherein the wheels are parallel to each other, and a splayed position, wherein the first and second hub assemblies are spread to a predetermined angle from each other to permit stowage of the landing gear within the landing gear bay with minimal intrusion. The first and second hub assemblies are actuatable between the splayed and unsplayed positions by first and second foldable linkage assemblies (84) and (88) and are reversibly driven by a linear hydraulic actuator (126).

Splayable aircraft nose landing gear

A steering method and system for large aircraft wherein during low speed taxi the main landing gear wheels are steered and the nose gear is free to castor. During high speed taxi such as during take off and landing, the main gear steering is locked out while the nose gear is steered.

Aircraft steering system and method for large aircraft having main

A variable orifice damper includes a sealed cylinder, a piston rod mounted for sliding movement along the axis of the cylinder carrying a piston head and a tail rod, the piston rod and tail rod extending from the interior of the cylinder outward beyond a corresponding support surface on the cylinder wall. The cylinder contains a cavity portion whose internal size varies along the cylinder axis located axially between two adjacent cavity portions of larger size than the intermediate cavity portion. The piston head has a surface whose cross sectional area varies along the axis of the cylinder and is adapted to pass through the cavity portion of variable size, the piston head and cavity portion defining a orifice of variable size therebetween. The piston rod has a bore containing a separator piston actuated by fluid passing the orifice and adapted to compress gas held in the bore.

Variable orifice oil/gass damper for aircraft landing gear

A high pressure hydropneumatic shock absorber (10) includes a cylinder (12) with a piston (16) slidably positioned within the cylinder (12). The piston (16) and cylinder (12) are configured as a telescopic suspension unit. The piston (16) defines a first variable volume chamber (28) within the cylinder (12) and is filled with a working liquid. A reservoir (44) includes an interior movable barrier wall (62) defining first (60) and second (64) separated variable volume reservoir chambers. The first reservoir chamber (60) is filled with working liquid and the second reservoir chamber (64) is filled with a working gas. A flow-controlling damper valve (58) communicates the first cylinder chamber (28) with the first reservoir chamber (60). Relative telescopic movement of the piston (16) and cylinder (12) cause damped flow of the working liquid from the first cylinder chamber (28) to the first reservoir chamber (60) and cause responsive movement of the barrier wall (62) to allow expansion of the first reservoir chamber (60) and corresponding reduction of the second reservoir chamber (64), thereby compressing the working gas. A method of charging a hydropneumatic shock absorber (10) having a telescopic piston cylinder unit (12, 16) comprises the steps of providing a first variable volume chamber (28) defined by the piston (16) within the cylinder (12). A flow-controlling damper valve (58) communicating the first chamber (28) with a reservoir (44) is also provided. The first chamber (28) and reservoir (44) are filled with a predetermined volume of a working liquid and a predetermined volume of a working gas at a predetermined pressure. Further working fluid is added, thereby compressing the working gas, until the working liquid and working gas reach a predetermined desired static pressure at a predetermine relative position of the piston 16 to the cylinder 12.

High pressure hydropneumatic shock absorber

A landing gear for an aircraft has a multi-wheeled truck that is swung by a main prop from a stowed position to a lowered position below the aircraft. The truck is pivotably connected to the lower end of the main prop. When the gear is lowered, at least one rear prop extends between the upper end of the main prop and an aft region of the wheel truck. Both the main and rear props are telescoping members. However, the rear prop is releasably lockable to hold a certain fixed length when the aircraft is on the ground, so as to prevent pivoting movement of the wheel truck relative to the main prop. This impedes the ability of the aircraft to tip back when its center of gravity shifts aft during unloading.

Multi-axled propped landing gear

A multiwheel landing gear assembly includes a forward set of wheels which are in tandem with a middle set of wheels which in turn are in tandem with a rear set of wheels. The forward set of wheels are connected to a main support strut of the landing gear by a levered arrangement. The middle and rear set of wheels are connected together by a truck beam which in turn is connected to the main support strut by a radius rod. When the middle and rear wheels are subject to an upward force such as when the aircraft is landing, the radius rod limits movement of the wheels in a generally upward direction along a path having a radius which is equal to the length of the radius rod. Movement of the middle and rear wheels along the path in the upward direction is resisted by a shock absorber. In this manner, the vertical loads are reacted in a lengthwise direction along the radius rod and shock absorber.

Multiwheeled trailing type landing gear assembly

A two-stage aircraft gear. The landing gear includes a cantilever landing gear whose lower end is attached to a trailing arm (or articulated) landing gear. The cantilever gear is a collapsible piston-cylinder assembly, and the trailing arm gear also has a shock absorber connected between a fixed portion of the trailing arm gear and the movable wheel support arm. When landing, the load imposed is first absorbed by the trailing arm landing gear. After the trailing arm gear has been fully compressed, the cantilever gear begins to compress. The cantilever and trailing arm landing gear can be combined to provide the desired performance. The landing gear static position can be designed to be in the static load curve of the first component, allowing the aircraft to be stably supported and yet difficult to overturn. Adjustable orifice plates contained within one or both of the cantilever and articulated stages can be controlled as a function of the vertical descent velocity and/or distance. If desired, differential pressure measurements within the two stages can be used to give the landing gear any desired damping and/or landing gear extension characteristic.

Adjustable two-stage aircraft landing gear system

A two-stage aircraft gear. The landing gear includes a cantilever landing gear whose lower end is attached to a trailing arm (or articulated) landing gear. The cantilever gear is a collapsible piston-cylinder assembly, and the trailing arm gear also has a shock absorber connected between a fixed portion of the trailing arm gear and the movable wheel support arm. When landing, the load imposed is first absorbed by the trailing arm landing gear. After the trailing arm gear has been fully compressed, the cantilever gear begins to compress. The cantilever and trailing arm landing gear can be combined to provide the desired performance. The landing gear static position can be designed to be in the static load curve of the first component, allowing the aircraft to be stably supported and yet difficult to overturn.

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Kirkland, WA, United States of America

Harry C Ralph