A landing gear system 100 for an aircraft including: a landing gear 130 that is movable between an extended position and a retracted position, the landing gear includes an extendible strut 136; a position sensor 140 configured to detect a position of a part of the extendible strut and output a signal indicative of the position; and a landing gear controller 150 that is communicably connected to the position sensor and is configured, in use, to: receive the signal from the position sensor; and, on the basis of the signal, determine that the strut has extended and the landing gear is in contact with the ground and automatically cause performance of at least a portion of a procedure to move the landing gear from the extended position to the retracted position

An aircraft assembly having landing gear with a known deployment value, apparatus for permitting landing gear deployment, down-lock sensing apparatus, a navigation system, a landing gear control system, a flight control system, and a deployment controller. The deployment controller is configured to: calculate a touch down value using the aircraft position and speed information provided by the aircraft navigation system; command the landing gear control system to provide the deploy signal when the touch down value reaches a deployment threshold value which is greater than the landing gear deployment value; and command the flight control system to execute a landing abort sequence if the controller does not receive the down-lock signal from the landing gear sensing apparatus within a deployment value window which is greater than or equal to the known deployment value for the landing gear but less than the touch down value.

An aircraft assembly having landing gear with a known deployment value, apparatus for permitting landing gear deployment, down-lock sensing apparatus, a navigation system, a landing gear control system, a flight control system, and a deployment controller. The deployment controller is configured to: calculate a touch down value using the aircraft position and speed information provided by the aircraft navigation system; command the landing gear control system to provide the deploy signal when the touch down value reaches a deployment threshold value which is greater than the landing gear deployment value; and command the flight control system to execute a landing abort sequence if the controller does not receive the down-lock signal from the landing gear sensing apparatus within a deployment value window which is greater than or equal to the known deployment value for the landing gear but less than the touch down value.

An uplock for use with an aircraft landing gear is disclosed having a hook configured to engage a capture pin mounted on the landing gear. The hook is mounted for movement between a closed and locked position and an open and unlocked position. A proximity detector directly detects whether the pin is up. An uplock hook sensor detects when the hook is in the closed and locked position. The outputs of the proximity detector and the uplock hook sensor may be used to indicate the up and locked condition, i.e., landing gear up, and/or to indicate a fault. Such outputs may be provided by an associated device of an avionics system.

An uplock for use with an aircraft landing gear is disclosed having a hook configured to engage a capture pin mounted on the landing gear. The hook is mounted for movement between a closed and locked position and an open and unlocked position. A proximity detector directly detects whether the pin is up. An uplock hook sensor detects when the hook is in the closed and locked position. The outputs of the proximity detector and the uplock hook sensor may be used to indicate the up and locked condition, i.e., landing gear up, and/or to indicate a fault. Such outputs may be provided by an associated device of an avionics system.

Landing gear monitoring systems and methods for an aircraft include a landing gear timing analysis control unit that is configured to analyze one or both of landing gear motion of one or more landing gears of the aircraft or door motion of one or more doors proximate to the landing gear(s) to determine an operational status of one or both of the landing gear(s) or the door(s).

A method 300 for deploying an aircraft landing gear including: receiving an aircraft landing gear deployment signal 310, receiving an aircraft position signal indicative of a distance of the aircraft from an aircraft landing site 320, receiving one or more flight signals indicating one or more dynamic conditions or parameters relating to the flight of the aircraft 330, determining, based at least on the one or more flight signals, a first aircraft position, relative to the aircraft landing site, at which the landing gear deployment should commence 340, and deploying the landing gear (a) when the aircraft reaches the first aircraft position, in the event that the deployment signal is received before the aircraft reaches the first aircraft position, or (b) immediately, in the event that the deployment signal is received when the aircraft has passed the first aircraft position 350.

A method 300 for deploying an aircraft landing gear including: receiving an aircraft landing gear deployment signal 310, receiving an aircraft position signal indicative of a distance of the aircraft from an aircraft landing site 320, receiving one or more flight signals indicating one or more dynamic conditions or parameters relating to the flight of the aircraft 330, determining, based at least on the one or more flight signals, a first aircraft position, relative to the aircraft landing site, at which the landing gear deployment should commence 340, and deploying the landing gear (a) when the aircraft reaches the first aircraft position, in the event that the deployment signal is received before the aircraft reaches the first aircraft position, or (b) immediately, in the event that the deployment signal is received when the aircraft has passed the first aircraft position 350.

An apparatus for determining a movement direction of a component of a mechanism. The apparatus includes an acoustic emission sensor arranged to detect acoustic emission from the mechanism, and a processor arranged to determine a Doppler shift in a frequency characteristic of the measured acoustic emission and to determine a movement direction of a component of the mechanism on the basis of the determined Doppler shift. A method of determining a movement direction of a component of a mechanism including detecting acoustic emission from the mechanism and determining a Doppler shift in a frequency characteristic of the measured acoustic emission and, determining, based on the Doppler shift in the frequency characteristic, a movement direction of the component of the mechanism.

An apparatus for determining a movement direction of a component of a mechanism. The apparatus includes an acoustic emission sensor arranged to detect acoustic emission from the mechanism, and a processor arranged to determine a Doppler shift in a frequency characteristic of the measured acoustic emission and to determine a movement direction of a component of the mechanism on the basis of the determined Doppler shift. A method of determining a movement direction of a component of a mechanism including detecting acoustic emission from the mechanism and determining a Doppler shift in a frequency characteristic of the measured acoustic emission and, determining, based on the Doppler shift in the frequency characteristic, a movement direction of the component of the mechanism.