As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 1522 - EN ROUTE MIA-ORD - DURING CRUISE, THE GREEN RESERVOIR HYDRAULIC LEVEL DROPPED TO MINIMUM. LANDING GEAR WAS LOWERED USING GRAVITY EXTENSION METHOD. LANDED ORD WITHOUT INCIDENT. REPLACED NR 2 ENGINE PRESSURE LINE AND BOTH ENGINE CASE DRAIN FILTERS FOR THE GREEN HYDRAULIC SYSTEM. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)