As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS-IAD - FLT 238 - DURING CRUISE, THE LEFT ENGINE OIL QUANTITY DROPPED TO ZERO AND THE OIL PRESSURE WAS ALSO DROPPING. THE LEFT ENGINE WAS SHUT DOWN AND THE AIRCRAFT DIVERTED TO PHL AND LANDED WITHOUT INCIDENT. SINGLE ENGINE TIME WAS 21 MINUTES. MAINTENANCE REPAIRED THE OIL FILTER HOUSING PER THE PWA TYPICAL REPAIR 72-61-2A. (M)