Aircraft Hydraulic System With A Dual Spool Valve And Methods Of Use

An assembly to position a flight control member of an aircraft, the assembly comprising:

• a hydraulic actuator operatively connected to the flight control member and comprising a piston, a first chamber on a first side of the piston, and a second chamber on a second side of the piston;
• a dual spool valve comprising:
• a first valve section comprising:
• a first manifold with a supply port, a return port, and an actuator port;
• a first closure line that extends to the first chamber of the actuator;
• and
• a first spool movable within the first manifold between a first position to allow hydraulic fluid to flow through the first valve section to and from the first chamber of the actuator through just the supply port, a second position to allow hydraulic fluid to flow through the first valve section to and from the first chamber of the actuator through just the return port, and a third position to allow hydraulic fluid to flow through the first valve section to and from the first chamber of the actuator through just the first closure line;
• a second valve section comprising:
• a second manifold with a supply port, a return port, and an actuator port;
• a second closure line that extends to the second chamber of the actuator;
• and
• a second spool movable within the second manifold between a first position to allow hydraulic fluid to flow through the second valve section to and from the second chamber of the actuator through just the supply port, a second position to allow hydraulic fluid to flow through the second valve section to and from the second chamber of the actuator through just the return port, and a third position to allow hydraulic fluid to flow through the second valve section to and from the second chamber of the actuator through just the second closure line.

A method of controlling an actuator connected to a flight control member of an aircraft, the method comprising:

• operating a dual spool valve in a first setting by selectively positioning a first spool between first and second positions to block and open a supply port and a return port in the first manifold and controlling hydraulic fluid into and out of a first chamber of the actuator and simultaneously selectively positioning a second spool between first and second positions to block and open a supply port and a return port in the second manifold and controlling hydraulic fluid into and out of a second chamber of the actuator;
• determining that the second spool has failed and moving the second spool to a failed position and blocking the supply port and the return port in the second manifold and opening a second supply port and moving hydraulic fluid into and out of the second chamber;
• and
• while the second spool is in the failed position, selectively positioning the first spool between the first and second positions to block and open the supply port and the return port in the first manifold and controlling hydraulic fluid into and out of the first chamber of the actuator.