Abstract: An aircraft landing gear shock absorber having an inner housing portion slidably coupled within an outer housing portion, and a chamber which defines a sealed fluid volume for containing shock absorber fluid within the shock absorber. The chamber includes a moveable wall portion arranged to move between a first position and a second position, and in the second position the effective volume of the chamber is decreased such that the shock absorber fluid pressure increases, to provide a bump to the shock absorber.

Abstract: An aircraft landing gear assembly includes a bi-stable, split line tube biased to assume a tubular condition to serve in place of a lock link or side stay and an actuator configured to radially enlarge the tube at a region for folding.

Abstract: A brake rod assembly for an aircraft landing gear. The brake rod assembly includes a support member, a first brake rod having a first pivot point and a second pivot point, and a second brake rod. The support member is coupled to the first pivot point, the second brake rod is coupled to the second pivot point, and the first and second pivot points are longitudinally spaced apart along a first portion of the first brake rod.

Abstract: An aircraft landing gear assembly having a main strut and an axle on which wheel and brake assemblies are mounted. An adaptor member is mounted on a mounting pin and arranged to define a brake rod anchor point. The adaptor member is coupled to a part of the landing gear assembly so as to react brake torque and can be formed from a different material than a portion of the main strut.

Abstract: An actuator arranged to be movable between an extended condition and a compressed condition and being biased to an intermediate condition between and distinct from the extended condition and the compressed condition. The actuator includes a damping device arranged to define the damping coefficient of the actuator.

Abstract: An aircraft landing gear having a strut having an upper portion for mechanically coupling to an aircraft and a lower portion movably mounted with respect to the upper portion. A bogie beam is pivotally coupled to the lower strut. A bogie control linkage is mechanically coupled to the bogie at a first connection point, and to the strut at a second connection point. The bogie control linkage has: an actuator including a locking system that inhibits actuation of the actuator; a sensor linkage mechanically coupled to the lower strut and arranged to change between first and second conditions in accordance with movement of the upper strut relative to the lower strut; and an actuator control linkage arranged to operate the locking system when the sensor linkage is in the first condition and arranged not to operate the locking system when the sensor linkage is in the second condition.

Abstract: A pitch trimmer assembly for an aircraft landing gear having a damping element arranged to be connected between a first and a second element of an aircraft landing gear and arranged to exert a first damping force when in a first state and a second damping force in a second state, the damping element being switchable between the first and second states in dependence on the relative positions of the first and second landing gear elements.

Abstract: A method of protecting an aircraft undercarriage (1) while it is being towed by means of a tow bar (13) hitched to a steerable bottom portion of the undercarriage, the method including the step of generating an alarm when a towing force imposed by the tow bar on the undercarriage reaches or exceeds a predetermined force threshold. The threshold is caused to vary as a function of an orientation of the steerable bottom portion of the undercarriage.

Abstract: A shock absorber assembly having a wheel assembly including first and second coupling points, and first and second shock absorber elements. Each shock absorber element includes a housing portion defining a bore, and a rod slidably coupled within the bore such that the shock absorber element has a variable length. Each rod is coupled to a respective coupling point of the wheel assembly. The shock absorber assembly is arranged to maintain the relative positions of the first and second housing portions such that the longitudinal axis of the first bore has a generally fixed relationship with respect to the longitudinal axis of the second bore.

Abstract: A brake assembly for a vehicle comprising a wheel comprising a hollow section and a rim, the rim comprising a first portion comprising an electrically conductive material and a second portion adjacent to the first portion comprising a plurality of a permanent magnets and a stator comprising at least one electromagnetic coil arranged to be located within the hollow section of the wheel, wherein the stator is moveable between a first position in which the at least one electromagnetic coil is inductively coupled to the first portion of the rim when the wheel is rotating relative to the stator, and a second position in which the at least one electromagnetic coil is inductively coupled to the second portion of the rim.

Abstract: A landing gear for an aircraft having a main fitting arranged to be coupled to the aircraft and arranged to move between a stowed condition and a deployed condition and a trailing arm movably coupled to the main fitting. A torsion spring is coupled to the trailing arm such that the movement of the trailing arm causes torsion loading of the torsion spring. A stay assembly is provided which comprises the torsion spring, the stay assembly having a first condition in which it is arranged to react axial loading thereof so as to maintain the main fitting in the deployed condition and a second condition in which it is arranged to permit the main fitting to move between the stowed condition and the deployed condition.

Abstract: An aircraft landing gear having a strut having an upper portion for mechanically coupling to an aircraft and a lower portion movably mounted with respect to the upper portion. A bogie beam is pivotally coupled to the lower strut. A bogie control linkage is mechanically coupled to the bogie at a first connection point, and to the strut at a second connection point. The bogie control linkage has: an actuator including a locking system that inhibits actuation of the actuator; a sensor linkage mechanically coupled to the lower strut and arranged to change between first and second conditions in accordance with movement of the upper strut relative to the lower strut; and an actuator control linkage arranged to operate the locking system when the sensor linkage is in the first condition and arranged not to operate the locking system when the sensor linkage is in the second condition.

Abstract: A gauge for indicating whether the oil level in an oleo-pneumatic shock absorber requires modification. The gauge comprises a substrate for positioning relative to the oleo-pneumatic shock absorber. The substrate has a first region arranged to encompass a range of possible oil levels within the shock absorber, a second region corresponding to a range of possible extension states of the shock absorber and a third region comprising one or more traces. Each trace corresponds to a temperature value and is indicative of an optimum relationship between the oil levels and the range of extension states at the respective temperature value associated with the trace.

Abstract: The invention relates to an electrohydraulic actuator comprising a body (1) that defines a cylindrical cavity (2) in which a piston (3) slides in leaktight manner and divides an inside volume of the cavity into two chambers (A, B) of variable volume, the piston being associated with at least one rod (4) passing in leaktight manner through an end wall of the cavity, the actuator including a bidirectional pump (5) having two ports (P1, P2), each connected to one of the chambers, an electric motor (8) for selectively driving the pump in one direction or the other, the pump being placed inside the piston of the actuator so as to move together therewith.

Abstract: A multifunction device for an undercarriage, the device comprising at least a first shaft rotatably mounted on the aircraft to rotate about an axis of rotation that is substantially parallel to a hinge axis hinging the undercarriage to the aircraft, a telescopic second shaft rotatably mounted in the undercarriage and extending down along the undercarriage to the proximity of wheels carried thereby, and motor means adapted to cause the first shaft to rotate. The telescopic second shaft is a single shaft and it extends inside the undercarriage to the proximity of an axle carrying the wheels of the undercarriage, being connected to a differential connected to the wheels via drive shafts extending inside the axle.

Abstract: A proximity sensor for detecting non-contact detection of a target using a fibre optic strain sensor and a system for operating multiple such proximity sensors is disclosed. The proximity sensor includes an optic fibre that has an optic fibre strain sensor that is coupled to a mass that moves in response to the target. The mass can be a magnet that moves when a ferrous target is within the magnetic field of the magnet causing the magnet to move and apply strain to the optic fibre strain sensor. The optic strain sensor can include periodic variation in the refractive index of the optic fibre, such as a fibre Bragg grating. The proximity sensor can include a second fibre optic sensor that is sensitive to temperature or a second fibre optic strain sensor coupled to a second magnet that operates in opposition to the first magnet. A system coupling multiple proximity sensors can include an interrogator that has an optical power source and a detector, each coupled to a processor.

Abstract: A multifunction electromechanical device for an aircraft undercarriage. The device comprises a first shaft (10) mounted to rotate on the aircraft about an axis of rotation (R) that is substantially parallel to a hinge axis (X) of the undercarriage relative to the aircraft and a telescopic second shaft (20) mounted to rotate on the undercarriage extending downwards to the proximity of the wheels carried thereby. The device also includes a transmission (19) for transmitting rotary motion from the first shaft to the second shaft and a transmission (21) for transmitting rotary motion from the second shaft to at least one wheel carried by the undercarriage. With this configuration, if the wheel is not fitted with a brake, there is a specific brake (30) for braking one of the shafts relative to the undercarriage, and a motor (11, 15) for causing the first shaft to rotate.

Abstract: Method and system of determining ground-to-tyre friction coefficient for an aircraft landing event. The method uses an aircraft computational model to repeatedly model the landing event, varying one or more initial conditions of the aircraft model until a best match between a modelled value and a provided value of aircraft vertical acceleration is determined. The method uses initial conditions associated with the best match of modelled and provided vertical acceleration values and a strain value from a sensor on the aircraft landing gear, with the ground-to-tyre friction coefficient is a variable. The method models the landing gear to generate a modelled strain value and compares this with the measured strain value, and repeats the landing gear modelling step with a different value for the ground-to-tyre friction coefficient until a best match between the modelled strain value and the measured strain value is determined and outputting the respective friction coefficient value.

Abstract: An uplock assembly for retaining and releasing landing gear systems, said uplock assembly comprising: a thermal actuator comprising: a chamber configured to contain expansible material therein; a heating mechanism coupled to said chamber for heating said expansible material and causing volumetric expansion thereof; a piston slidably coupled to said chamber and adapted to extend in response to said volumetric expansion; and an uplock release mechanism releasably engaged by said piston when extended such that said engaged uplock release mechanism causes the release of said landing gear.

Abstract: This invention allows for the precise determination of an aircraft's landing conditions and whether an aircraft has experienced a hard landing that exceeds the allowable design loads of the aircraft's landing gear. The system comprises a computer that measures signals from an inertial measurement unit (IMU) at high data rates (e.g. 100 Hz) and also records signals from the aircraft avionics data bus. The computer compares the output from the inertial measurement unit's accelerometers against at least one predetermined threshold parameter to determine whether the aircraft's three dimensional landing deceleration is safely within the design allowances or other regulatory limitations, or whether the landing event needs further investigation.