Airbus Operations Gmbh

Airbus Operations (s.a.s.)

Andy Mounty

Matthew Marples

Sean Kerr

Laurent Tizac

Graham King

Christopher Papadopoulos

Costas Fanourakis

Robert Venn

Paul L'allier

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

Aircraft hydraulic actuation system with chambers for hydraulic fluid

An aircraft landing gear is disclosed including a main leg, a foldable stay and a lock link configured to hold the foldable stay in position when the landing gear is extended. The foldable stay includes a first stay member and a second stay member, and the landing gear is configured such that the second stay member rotates in a first direction from a first position to a second position as the landing gear moves from a retracted configuration to an extended configuration. An end stop is arranged such that in the event the lock link fails, the second stay member rotates in the first direction from the second position to a third position in which the stay contacts the end stop thereby preventing further movement of the second stay member in the first direction and wherein the foldable stay goes over centre as the second stay member moves from the first position to the third position.

Retractable aircraft landing gear

A landing gear system for an aircraft includes a retractable landing gear assembly, a hydraulic actuator for actuating movement part, for example a bogie of the landing gear assembly, and an accumulator associated with the actuator. The accumulator comprises a volume of pressurised gas separated from hydraulic fluid by a separator piston. Travel of the separator piston beyond a certain position is indicative of a fault. The accumulator includes a snubbing device that acts to slow movement of the separator piston beyond that position. A monitoring system measures the time taken for the movement of the landing gear part effected by the hydraulic actuator. If the measured time is longer than a threshold time, that is indicative of a possible fault in the accumulator, that might, without the snubbing, remain undetected and/or hidden from view.

Hydraulic actuator and accumulator arrangement

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Bristol, United Kingdom

Andy Mounty