Thrust reverser for a jet engine and hydraulic actuator

An hydraulic system for a thrust reverser assembly of the kind comprising at least one thrust reverser element which, during normal use in association with a jet engine, is movable between a stowed position and a deployed position and is so arranged as to experience an assisting load during movement of the element from the stowed position towards the deployed position and , a double-acting hydraulic piston and cylinder device for moving said element between said stowed and deployed positions, said hydraulic piston and cylinder device having a first port through which hydraulic fluid under pressure can be admitted to one side of said device, said one side of the device being a high pressure side during operation of the device in a thrust reverser element deploy mode, and, a second port through which hydraulic fluid can be displaced from a low pressure side of the device during operation in said deploy mode, the hydraulic system comprising, an hydraulic fluid pressure source for connection to said first port, a return line for connection between said first and second ports and through which in use hydraulic fluid displaced from said low pressure side of said device is returned to said high pressure side of said device in addition to fluid supplied in use from said hydraulic fluid pressure source, and, a check valve in said return line in use preventing flow of hydraulic fluid from said high pressure side to said low pressure side of said double-acting hydraulic piston and cylinder device.