What was found
DURING CRUISE, NR 4 OIL QUANTITY DROPPED TO ZERO, OIL PRESSURE FLUCTUATED 20-45 PSI. ENGINE WAS SHUT DOWN. AFTER SHUTDOWN, OIL PRESSURE MAINTAINED 0-5 PSI. ENGINE WINDMILLED FOR 48 MINUTES. REPLACED NR 4 ENGINE IAW ABX WORK CARD 8090501, DC8 A AND B.