What was found
PTY INFLIGHT T966/28OCT UIO TO MIA - LEFT ENGINE OIL QUANTITY WENT TO ZERO IN CRUISE FOLLOWED BY PRESSURE AND PRESSURE INDICATION LIGHT ILLUMINATED. CREW SHUT DOWN ENGINE. LANDED PTY WITHOUT INCIDENT. SINGLE ENGINE TIME 60 MINUTES. FOUND OIL TANK CAP LOOSE. SERVICED ENGINE WITH OIL. REPLACED OIL CAP AT PTY. MIA REPLACED CAP ASSEMBLY HOUSING AND CHECK VALVE FOR ENGINEERING EVALUATION. SYSTEM GROUND CHECKED NORMAL OPERATION.