What was found
ORD - FLT 7554 - UPON INITIAL DESCENT INTO ORD, A/C STARTED TO FILL UP WITH SMOKE AND FUMES. AT APPROX THE SAME TIME THE NR 3 SYSTEM SHOWED LEAKAGE. APPLICABLE EMERGENCY CHECKLISTS WERE PERFORMED AND THE CREW REQUESTED AN IMMEDIATE APPROACH TO RUNWAY. AIRCRAFT WAS IMMEDIATELY INSPECTED FOR FIRE OR DAMAGE. NONE FOUND. MAINTENANCE CREW INSPECTED NR 3 ENGINE AND FOUND A CHAFED/RUPTURED HYDRAULIC LINE AND PNEUMATIC DUCT. REF EIA2001232. (M)