An aircraft hydraulic system 199 has an electrohydraulic servo valve 6 connected to a hydraulic fluid path 5; a hydraulically actuated mechanism 3a,3b connected to the fluid path, actuated when force is applied to the fluid by the valve; a hydraulic fluid port 9 to allow fluid to escape the system when opened; and a hydraulic fuse 8 in the fluid path between the value and the port, arranged to move towards a closed state when fluid pressure differential across the fuse is above a threshold, and towards an open state allowing fluid to pass when below the threshold. The method of removing the fluid from the system involves opening the port and controlling the activation of the valve to force fluid to escape the system without the hydraulic fuse entering, and remaining in, the closed state. Preferably, the valve is activated, below a maximum level, and deactivated repeatedly for periods of time, alternately forcing fluid to escape and allowing the pressure differential across the fuse to fall. The time periods for activation/deactivation may be predetermined using a test system. The valve may be controlled using the output of a fuse internal component position sensor 200 and/or an accelerometer (fig.6,300).
A method of removing hydraulic fluid from an aircraft hydraulic system, an aircraft hydraulic system, and an aircraft
2022-01-26
Patent
Electronic Resource
English
IPC: | B64F GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT , Boden- oder Flugzeugträgerdeckeinrichtungen besonders ausgebildet für die Verwendung in Verbindung mit Luftfahrzeugen / B60T Bremsanlagen für Fahrzeuge oder Teile davon , VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF / F15B SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL , Druckmittelbetriebene Systeme allgemein |
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