What was found
AFTER TAKE-OFF OF ALITALIA (ALI) MD-80 AIRCRAFT I-DANV(80C369) ON 26 FEBRUARY 2003, AIRCRAFT EXPERIENCED HYDRAULIC FLUID LEAK DURING FLAP RETRACTION. AFTER THE AIRCRAFT LANDED, PTU, P/N 4100310-6, S/N 730C WAS REPLACED. THE SUBJECT PTU WAS RETURNED TO THE MANUFACTURE FOR A FAILURE INVESTIGATION, AND INSPECTION REVEALED THE DRAIN PORT HOUSING, P/N 4102202-1, HAD CRACKED COMPLETELY AROUND THE CIRCUMFERENCE. SUBJECT PTU HAD ACCUMULATED 29,221 FLIGHT HOURS, AND 22,663 CYCLES SINCE NEW. SUBJECT HOUSING HAD ACCUMULATED A TOTAL OF 14,590 HOURS SINCE INSTALLATION IAW S.B. 4100310-29-0031 (AD 92-33-03).