What was found
MXI - FLT 009 - AT CRUISE FLIGHT, CREW NOTICED RIGHT HYDRAULIC SYSTEM QUANTITY WAS DOWN TO 1 QUART. RIGHT HYDRAULIC PRESSURE DROPPED AND PRESSURE LOW LIGHT AND RUDDER CONTROL MANUAL LIGHTS CAME ON. LANDED AT MCI WITHOUT INCIDENT AFTER PERFORMING QRH PROCEDURE. LEFT SYSTEM GAVE NORMAL INDICATIONS. MAINTENANCE FOUND AFT VENTRAL STAIRS CONTROL VALVE LINE LEAKING AND REPLACED SUPPLY LINE. (M)