Narrative:

Preflight; taxi; and takeoff were normal. There were several cells east and south of the airport. After takeoff; captain suggest to select continuous power for climb over some building clouds and I agreed. We were given vectors and finally cleared the WX and were proceeding direct to cluts (our coast out point). We had already logged on and I had engaged the autoplt. The captain was printing out the flight update when I noticed the engine parameters appeared on the upper EICAS. I waited for the captain to complete his tasks and I selected the engine page. I noticed that the left engine oil quantity was indicating zero. I brought this to the attention of the captain and the third pilot. We were climbing out of FL240 and the captain asked hcf for a leveloff; we were cleared to level off at FL290. As the aircraft leveled off; I suggested we slow up a bit to remain in radar contact. We received clearance to slow down. As the power decreased the left engine oil quantity rose to approximately 6 quarts. The left engine oil temperature was approximately 40 degrees warmer than the right engine. The oil pressure on both engines was normal. The captain called dispatch and got a phone patch to maintenance. Maintenance took some snap shots of the engine parameters from our takeoff roll to our climb out and noticed that the oil quantity was normal on takeoff but began to decrease somewhat on climb out. Maintenance stated that with the engine reading 1 quart; we still had 13 quarts in the engine. Maintenance suggested we continue to ZZZ and monitor the engine parameters. The captain and I immediately looked at each other and decided simultaneously that we were not comfortable flying the aircraft at night over the pacific with little to no oil quantity on the left engine. The captain told maintenance that we were going to return to hnl and ask dispatch to check our overweight landing performance to see if dumping fuel was necessary or could we land overweight. During this entire process; we had a B767 captain that was on vacation riding in coach; to look out the window and see if he noticed any fluid leaking from the left engine. He called back and said he could see a stream of something leaking from the pylon. We requested a clearance to return to hnl but did not declare an emergency. We elected to reduce the thrust on the left engine to minimize the oil loss (if possible). We left the left engine at idle until turning final and then used the engine as normal for our landing. The return trip back to hnl; approach; landing; and taxi back to the gate was normal. Oil leak discovered by maintenance on ground left engine.

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Original NASA ASRS Text

Title: B777 FLT CREW REPORTS LOW OIL QUANTITY PASSING FL240 EASTBOUND OUT OF HNL AND ELECTS TO RETURN FOR MAINTENANCE.

Narrative: PREFLT; TAXI; AND TKOF WERE NORMAL. THERE WERE SEVERAL CELLS E AND S OF THE ARPT. AFTER TKOF; CAPT SUGGEST TO SELECT CONTINUOUS PWR FOR CLB OVER SOME BUILDING CLOUDS AND I AGREED. WE WERE GIVEN VECTORS AND FINALLY CLRED THE WX AND WERE PROCEEDING DIRECT TO CLUTS (OUR COAST OUT POINT). WE HAD ALREADY LOGGED ON AND I HAD ENGAGED THE AUTOPLT. THE CAPT WAS PRINTING OUT THE FLT UPDATE WHEN I NOTICED THE ENG PARAMETERS APPEARED ON THE UPPER EICAS. I WAITED FOR THE CAPT TO COMPLETE HIS TASKS AND I SELECTED THE ENG PAGE. I NOTICED THAT THE L ENG OIL QUANTITY WAS INDICATING ZERO. I BROUGHT THIS TO THE ATTN OF THE CAPT AND THE THIRD PLT. WE WERE CLBING OUT OF FL240 AND THE CAPT ASKED HCF FOR A LEVELOFF; WE WERE CLRED TO LEVEL OFF AT FL290. AS THE ACFT LEVELED OFF; I SUGGESTED WE SLOW UP A BIT TO REMAIN IN RADAR CONTACT. WE RECEIVED CLRNC TO SLOW DOWN. AS THE PWR DECREASED THE L ENG OIL QUANTITY ROSE TO APPROX 6 QUARTS. THE L ENG OIL TEMP WAS APPROX 40 DEGS WARMER THAN THE R ENG. THE OIL PRESSURE ON BOTH ENGS WAS NORMAL. THE CAPT CALLED DISPATCH AND GOT A PHONE PATCH TO MAINT. MAINT TOOK SOME SNAP SHOTS OF THE ENG PARAMETERS FROM OUR TKOF ROLL TO OUR CLBOUT AND NOTICED THAT THE OIL QUANTITY WAS NORMAL ON TKOF BUT BEGAN TO DECREASE SOMEWHAT ON CLBOUT. MAINT STATED THAT WITH THE ENG READING 1 QUART; WE STILL HAD 13 QUARTS IN THE ENG. MAINT SUGGESTED WE CONTINUE TO ZZZ AND MONITOR THE ENG PARAMETERS. THE CAPT AND I IMMEDIATELY LOOKED AT EACH OTHER AND DECIDED SIMULTANEOUSLY THAT WE WERE NOT COMFORTABLE FLYING THE ACFT AT NIGHT OVER THE PACIFIC WITH LITTLE TO NO OIL QUANTITY ON THE L ENG. THE CAPT TOLD MAINT THAT WE WERE GOING TO RETURN TO HNL AND ASK DISPATCH TO CHK OUR OVERWT LNDG PERFORMANCE TO SEE IF DUMPING FUEL WAS NECESSARY OR COULD WE LAND OVERWT. DURING THIS ENTIRE PROCESS; WE HAD A B767 CAPT THAT WAS ON VACATION RIDING IN COACH; TO LOOK OUT THE WINDOW AND SEE IF HE NOTICED ANY FLUID LEAKING FROM THE L ENG. HE CALLED BACK AND SAID HE COULD SEE A STREAM OF SOMETHING LEAKING FROM THE PYLON. WE REQUESTED A CLRNC TO RETURN TO HNL BUT DID NOT DECLARE AN EMER. WE ELECTED TO REDUCE THE THRUST ON THE L ENG TO MINIMIZE THE OIL LOSS (IF POSSIBLE). WE LEFT THE L ENG AT IDLE UNTIL TURNING FINAL AND THEN USED THE ENG AS NORMAL FOR OUR LNDG. THE RETURN TRIP BACK TO HNL; APCH; LNDG; AND TAXI BACK TO THE GATE WAS NORMAL. OIL LEAK DISCOVERED BY MAINT ON GND L ENG.

Data retrieved from NASA's ASRS site as of May 2009 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.