As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE ACFT WAS BEING FLOWN ON A POST-MAINTENACE ACCEPTANCE CHECK FLIGHT. SHORTLY AFTER TAKEOFF, THE FLIGHT ENGINEER NOTED A NOTICABLE DROP IN THE OIL QUANITY ON THE NR1 ENGINE. THE OIL QUANITY WAS BELOW 2 QUARTS. 15 MINUTES AFTER LEVEL OFF OIL QUANITY DROPPED TO APPROXIMATELY 1.0 GALLONS. THE DECISION WAS MADE TO RETURN TO DEPARTURE. FUEL DUMP WAS COMMENCED TO REDUCE THE ACFT MAXIUM LANDING WEIGHT, THE ACFT WAS TURNED AROUND BACK TO DEPARTURE. THE OIL QUANITY WAS BECOMING LOWER AND THE DECISION WAS MADE TO PERFORM A PRECAUTIONARY SHUTDOWN OF THE NR 1 ENGINE.