What was found
AT APPROX 0730Z, THE CREW EXPERIENCED NR 3 ENG LOSS OF OIL QTY, FOLLOWED BY LOW OIL PRESS, HIGH ENG EMP AT FL 330. DECLARED AN EMER AT 0738Z & AIR RETURNED BACK SAFELY AT 0908Z. TROUBLESHOOTING IN PROGRESS. R & R NR 3 ENG GEARBOX IAW AMM 72-63-00. INSPECTED MAIN OIL FILTER. PERFORMED ENG RUN, LEAK CHECKED GOOD. MAIN OIL FILTER INSPECTION GOOD, NO DEBRIS NOTED. REQUIRES REPEAT INSPECTION & OIL ANALYSIS AFTER 1ST FLIGHT, 15 HRS, 25 HRS, 50 HRS, 75 HRS & 100 HRS FOR MONITOR. UPDATE PARTS INFORMATION.