As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENG OIL QTY STARTED TO DECREASE IN CRUISE. OIL DROPPED TO 6.5 GAL, PSI 46/48 TEMP 85/85 QTY 6.5/18. ZERO OIL QTY CAME BACK UP TO 20 QTY ON TAXI IN. NR 1 ENG INSPECTED FOR OIL LEAK ACC MM 79-00-00, NO LEAK OBSERVED. ENG SERVICE TO NORMAL AND AFTER ENG RUN UP FOR 20 MIN, ALL PARAMETERS ARE CORRECT AND NO EXTERNAL LEAK OBSERVED. NOTE: MTSI OPENED FOR FURTHER TROUBLESHOOTING OF OIL INDICATION SYS.