What was found
TRIP ID NR 1092724 WHILE ON DESCENT, THE HYDRAULIC FLUID QUANTITY DROPPED DOWN TO 15 PERCENT. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT WAS DIVERTED, WHERE A SAFE LANDING WAS MADE. DURING A POST FLIGHT INSPECTION HYDRAULIC FLUID WAS FOUND TO BE COVERING THE BELLY OF THE AIRCRAFT. FOUND (A) SYSTEM PRESSURE LINE FOR AILERON SHIFT CHAFED. REMOVED OLD LINE AND INSTALLED A NEW LINE. OPERATED, BLED AND LEAK CHECK OF HYDRAULIC LINE CHECKS GOOD.