What was found
DURING CRUISE AT FL410, THE AIRCRAFT BEGAN TO ROCK LATERALLY AND THE CYAN ALERION RATIO LOW ICAS MESSAGE ILLUMINATED. THE A SYSTEM HYDRAULIC QTY WAS INDICATING APROX 25%. QUANTITY DECREASED TO 17% UNTIL AFTER GEAR EXTENSION WHEN QUANTITY DECREASED TO 4%. EMERGENCY BRAKING SYSTEM WAS USED ON LANDING. TROUBLESHOT AND FOUND RIGHT MAIN LANDING GAR RETRACT ACTUATOR HYDRAULLC HOSE LEAKING. REMOVED AND REPLACED THE HOSE IAW MM 32-30-00. OPS AND LEAK CHECKED NORMAL.