Narrative:

En route from sfo-nrt/tyo in vicinity of cold bay, ak, noted low oil quantity (3 gals) in #3 engine. Second officer made visibility inspection of engine cowling from cabin. Further wbound, over shemya, oil quantity had dropped to 1 1/2 gals. After consultations with company maintenance headquarters and dispatcher, elected to forego landing at shemya, or return to anc and continued toward chitose (sapporo, japan). Requested change of route to adjacent arwy (R590 at pampo intersection) to facilitate descent to FL290 for purpose of operating #3 engine at idle thrust to conserve oil. Although oil quantity subsequently dropped to 0, oil temperature and oil pressure remained normal for remainder of flight. Continued on to nrt, by-passing chitose because of lack of maintenance at chitose. Requested emergency equipment standby for landing at nrt/tyo. Approach and landing made with #3 at idle thrust. Shut down #3 engine after landing. Post flight revealed oil seal leak from #3 engine driven fuel pump repair. 15 1/2 qts oil added to #3 engine and seal replaced on fuel pump drive. It could be argued that aircraft should have returned to anc or landed at chitose, or even shemya.

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Original NASA ASRS Text

Title: ACR WDB ON EXTENDED OVER-WATER OPERATION LOW OIL QUANTITY ON #3 ENGINE. FLT CREW ELECTED TO CONTINUE TO DESCENT AT REDUCED POWER ON THAT ENGINE.

Narrative: ENRTE FROM SFO-NRT/TYO IN VICINITY OF COLD BAY, AK, NOTED LOW OIL QUANTITY (3 GALS) IN #3 ENG. S/O MADE VIS INSPECTION OF ENG COWLING FROM CABIN. FURTHER WBOUND, OVER SHEMYA, OIL QUANTITY HAD DROPPED TO 1 1/2 GALS. AFTER CONSULTATIONS WITH COMPANY MAINT HQ AND DISPATCHER, ELECTED TO FOREGO LNDG AT SHEMYA, OR RETURN TO ANC AND CONTINUED TOWARD CHITOSE (SAPPORO, JAPAN). REQUESTED CHANGE OF RTE TO ADJACENT ARWY (R590 AT PAMPO INTXN) TO FACILITATE DSNT TO FL290 FOR PURPOSE OF OPERATING #3 ENG AT IDLE THRUST TO CONSERVE OIL. ALTHOUGH OIL QUANTITY SUBSEQUENTLY DROPPED TO 0, OIL TEMP AND OIL PRESSURE REMAINED NORMAL FOR REMAINDER OF FLT. CONTINUED ON TO NRT, BY-PASSING CHITOSE BECAUSE OF LACK OF MAINT AT CHITOSE. REQUESTED EMER EQUIP STANDBY FOR LNDG AT NRT/TYO. APCH AND LNDG MADE WITH #3 AT IDLE THRUST. SHUT DOWN #3 ENG AFTER LNDG. POST FLT REVEALED OIL SEAL LEAK FROM #3 ENG DRIVEN FUEL PUMP REPAIR. 15 1/2 QTS OIL ADDED TO #3 ENG AND SEAL REPLACED ON FUEL PUMP DRIVE. IT COULD BE ARGUED THAT ACFT SHOULD HAVE RETURNED TO ANC OR LANDED AT CHITOSE, OR EVEN SHEMYA.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.