What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED COMMING INTO THE SCHEDULED DESTINATION OF AUA . AT FL 330 GREEN HYDRAULIC SYSTEM QUANTITY INDICATED ZERO. FLIGHT CREW RAN ECAM AND TURNED OFF GREEN PUMP. TURNED BACK ON FOR GEAR EXTENSION AND GEAR EXTENDED NORMALLY. INDICATION IS WELL BELOW NORMAL RANGE. THE AIRCRAFT LANDED SAFELY AT AUA WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE ENGINE DRIVEN HYDRAULIC PUMP ON #1 ENGINE LEAKING AND REPLACED IT PER AMM 29-11-51. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.