The invention provides a drive system for rotating a wheel of an aircraft landing gear. The drive system includes a motor operable to rotate a drive pinion, and a driven gear adapted to be mounted to the wheel. The drive system has a first configuration in which the drive pinion is capable of meshing with the driven gear to permit the motor to drive the driven gear and a second configuration in which the drive pinion is not capable of meshing with the driven gear. The drive system includes a linear positioning actuator for moving the drive pinion relative to the driven gear. The positioning actuator has a first end and a second end, the first end having a pivotal connection with a pivot axis spaced at a fixed distance from an axis of rotation of the driven gear, and the second end having a pivotal connection with a pivot axis spaced at a fixed distance from an axis of rotation of the drive pinion.

A drive system 20, 20′ for rotating a wheel 11, 11′ of an aircraft landing gear 10, 10′, is disclosed having a drive element 24, 24′, a motor 21, 21′ operable to rotate the drive element, and a driven gear 25, 25′ adapted to be attached to the wheel. The drive system has a drive configuration in which the drive element is capable of meshing with the driven gear to drive the driven gear, wherein the drive system further comprises a transmission error measurement apparatus 30, 40, the apparatus configured to obtain, over time, measurement data of one or more characteristics of the drive system when in the drive configuration, the measurement data providing an indication of a transmission error between a torque commanded by the motor and a resulting torque at the driven gear. An aircraft 100 and a method of providing an indication of a transmission error in a drive system is disclosed.

A method of inspection or maintenance of a curved ferromagnetic surface using an unmanned aerial vehicle (UAV) having a releasable crawler is provided. The method includes: flying the UAV from an initial position to a pre-perching position in a vicinity of the ferromagnetic surface; autonomously perching the UAV on the ferromagnetic surface; maintaining magnetic attachment of the perched UAV to the ferromagnetic surface; releasing the crawler from the magnetically attached UAV onto the ferromagnetic surface; moving the crawler over the curved ferromagnetic surface while maintaining magnetic attachment of the released crawler to the ferromagnetic surface; inspecting or maintaining the ferromagnetic surface using the magnetically attached crawler; and re-docking the released crawler with the perched UAV.

A landing gear system includes an axle having an internal cavity and a wheel rotatably coupled to the axle. A drive shaft is mounted within the cavity to be rotatable about an axis. The landing gear system further includes a rod slidably mounted within the drive shaft and a clutch. The clutch has a first portion that is coupled to the rod and rotates with the drive shaft. A second portion of the clutch is fixedly coupled to the wheel. The rod selectively reciprocates along the axis between a first position and a second position to engage and disengage the clutch.

An aircraft landing gear arrangement (1, 101) on an aircraft, the arrangement including a wheel (2, 22), a brake (6) operable to inhibit rotation of the wheel, one or more fan blades (7a, 7b) rotatable to cool the brake, and a brushless DC motor (8) operable to rotate the one or more fan blades.

A piece of electrical equipment for connecting both to at least one electromechanical braking actuator and also to at least one electromechanical drive actuator, the piece of electrical equipment (13a) comprising a housing (30), means for fastening the housing to the undercarriage, and inside the housing: a processor unit (32) arranged to generate a braking motor control signal and a drive motor control signal; a power supply unit (37) arranged to generate an equipment power supply voltage, a braking power supply voltage, and a drive power supply voltage; a power converter unit (40) arranged to generate a braking control voltage and a drive control voltage; and a distribution unit arranged to distribute the braking control voltage to the electromechanical braking actuator and the drive control voltage to the electromechanical drive actuator.

A method of operating an electromechanical actuator includes coupling an inner portion of a split ball screw with an outer portion of the split ball screw, rotating the split ball screw about an axis to drive a ball nut in a first axial direction, in response to a failure mode of the electromechanical actuator, decoupling the outer portion of the split ball screw from the inner portion of the split ball screw, and translating the outer portion of the split ball screw and the ball nut in a second axial direction.

A method of operating an electromechanical actuator includes coupling an inner portion of a split ball screw with an outer portion of the split ball screw, rotating the split ball screw about an axis to drive a ball nut in a first axial direction, in response to a failure mode of the electromechanical actuator, decoupling the outer portion of the split ball screw from the inner portion of the split ball screw, and translating the outer portion of the split ball screw and the ball nut in a second axial direction.

An aircraft wheel includes a rim that is secured to a central hub defining an axis of rotation of the wheel. The wheel includes one or more driving pins that extend from the hub, projecting in a direction substantially parallel to the axis of rotation of the wheel so as to cooperate with a driving member for driving the wheel in rotation. The driving pin is distinct from bolts assembling together parts of the wheel.

An aircraft landing gear comprising: a shock-absorbing main leg having a sprung part for attachment to an aircraft and an un-sprung part including a slider and an axle carrying at least one wheel, the wheel having a toothed ring gear; a drive transmission mounted externally on the sprung part, or on the un-sprung part, of the main leg, the drive transmission having at least one motor and a drive pinion for meshing with the toothed ring of the wheel; and an actuator for lifting the drive transmission into and out of driving engagement with the toothed ring and for maintaining the driving engagement as the landing gear deflects during a ground taxiing operation. Also, a method of operating the aircraft landing gear.