In the 2013-2014 year, the Eaton Aerospace Clinic team replaced an existing electro-hydraulic servo valve with a direct drive servo valve for an aircraft hydraulic steering system. The team designed, prototyped, and tested valves that proportionately direct the hydraulic fluid. The team reached the stretch goal both semesters and created two working prototypes to compare against one another. The final valve design is more economical and increases reliability and manufacturability while meeting performance criteria specified by Eaton Aerospace.