|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0001 To 0600|
|Locale Reference||atc facility : nqm|
|Altitude||msl bound lower : 29000|
msl bound upper : 39000
|Controlling Facilities||artcc : zoa|
|Operator||common carrier : air carrier|
|Make Model Name||Widebody, Low Wing, 4 Turbojet Eng|
|Navigation In Use||Other|
|Flight Phase||cruise other|
|Route In Use||enroute : other oceanic|
enroute : pacific
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : flight engineer|
pilot : atp
|Experience||flight time last 90 days : 77|
flight time total : 13770
flight time type : 2477
|Function||flight crew : second officer|
|Qualification||pilot : flight engineer|
|Anomaly||aircraft equipment problem : critical|
|Independent Detector||aircraft equipment other aircraft equipment : unspecified|
|Resolutory Action||flight crew : declared emergency|
Aircraft arrived osa from nrt. The logbook indicated the #3 engine had been shut down anl-nrt on flight prior to nrt-osa leg for loss of oil in #3 engine. Nrt maintenance worked on the engine and replaced various seals and I believe evc. The engine was run and leak checked. After arrival osa, 1 qt of oil was added to #3 oil tank. I am not aware of any visible leakage by either second officer or osa maintenance. We departed osa at XA45Z and climbed to FL390 on course to the oceanic track. Approximately 2 hours into the flight, second officer notified me that #3 engine oil quantity was decreasing on the gauge and had decreased approximately .5 gal in the previous 30 mins. We monitored the gauge for a period of time. I retarded the thrust lever as a precaution. The oil loss appeared to subside and stabilize at 1.3 gals. When the thrust lever was advanced, the quantity increased to 1.7 gals and stayed for quite a long time. In that the engine had been worked on, run and leak checked, I couldn't rule out an erroneous gauge as well as the possibility of loss of oil. A precautionary request for descent from FL390 to FL350 was initiated and unavailable due to an air carrier B flight directly beneath us at FL370. He was then visually sighted. I notified ATC there was the possibility of an engine shutdown. I spoke with the air carrier B crew and advised them that should it be necessary, I would leave course to the right before descending. A phone patch was requested to nrt dispatch--could not be put through. Tyo control said unable. Msp dispatch was contacted and we discussed the situation and I was told to standby while the dispatcher tried to contact nrt (no contact). I was given a release back to nrt, but in that the quantity had been stable for quite a while, we concurred to continue (tyo dispatch later concurred). The quantity dropped to 1 gal and then returned to 1.2 gals and stayed there quite a while. We had computed an etp (4 engine) and additionally determined that we could maintain FL330 should a shut down become necessary. The additional fuel burn would be approximately equivalent to our plus figure on the fuel score. The gauge began to drop to less than 1 gal. I had noted that the previous flight had low pressure indications at .75 gals. At .6 gals indicated, both pressure and temperature were all indicating normal. Approximately 350 mi past the etp, the low oil pressure light flickered dimly, oil pressure still 49 psi (I believe). I elected to exercise my emergency authority, leave track to the right and parallel 25 NM. Air carrier B was visually a few mi in front of us. I descended to FL335 per contingency instructions. Engine was shut down at XE37Z for precautionary purposes while oil was still in tank for windmilling quantity and pressure. ATC advised that air carrier B was the only traffic we had. We were unable to maintain chart speed with chart power, so descended from FL330 to FL310. ATC gave us a block altitude of FL290/310. Midway island was considered, but due to lack of familiarity, darkness and the fact hnl was clear and we would be arriving at a familiar airport in daylight and fuel was not critical, the decision was made to continue. #3 engine was carrying positive pressure and supply and all other systems were normal. Dispatch called with fuel calculations and also advised the computer showed we should be at FL290, so I took advantage of the block clearance descending to FL290 and advised ATC of the change. The remainder of the flight was uneventful and we blocked into hnl at XI09Z with 25000# of fuel on board. Running fuel calculations were made by me and never less than 24480# was planned on arrival. The emergency equipment was asked for on landing as a precautionary measure and allowed to secure after an uneventful landing. It may be only perception, but the oil gauge appeared to decrease more noticeable after the second time it showed 1 gal remaining. Callback conversation with reporter revealed the following: reporter said that it was possible to maintain FL330, but that the fuel flow required to do so was higher than charted. The advice to descend to FL290 given by dispatch was to provide the lowest fuel burnout to destination. Reporter said that he had to declare an emergency in order to descend, but that as soon as he got below air carrier B he was given a hard altitude and put back on track by ARTCC. Reporter said he had been told that the cause of the oil leak was a number of minor seal leaks--the same ones that had been worked on by maintenance in japan.
Original NASA ASRS Text
Title: ENGINE SHUTDOWN DUE TO OIL LOSS ON EXTENDED OVERWATER FLT.
Narrative: ACFT ARRIVED OSA FROM NRT. THE LOGBOOK INDICATED THE #3 ENG HAD BEEN SHUT DOWN ANL-NRT ON FLT PRIOR TO NRT-OSA LEG FOR LOSS OF OIL IN #3 ENG. NRT MAINT WORKED ON THE ENG AND REPLACED VARIOUS SEALS AND I BELIEVE EVC. THE ENG WAS RUN AND LEAK CHKED. AFTER ARR OSA, 1 QT OF OIL WAS ADDED TO #3 OIL TANK. I AM NOT AWARE OF ANY VISIBLE LEAKAGE BY EITHER S/O OR OSA MAINT. WE DEPARTED OSA AT XA45Z AND CLBED TO FL390 ON COURSE TO THE OCEANIC TRACK. APPROX 2 HRS INTO THE FLT, S/O NOTIFIED ME THAT #3 ENG OIL QUANTITY WAS DECREASING ON THE GAUGE AND HAD DECREASED APPROX .5 GAL IN THE PREVIOUS 30 MINS. WE MONITORED THE GAUGE FOR A PERIOD OF TIME. I RETARDED THE THRUST LEVER AS A PRECAUTION. THE OIL LOSS APPEARED TO SUBSIDE AND STABILIZE AT 1.3 GALS. WHEN THE THRUST LEVER WAS ADVANCED, THE QUANTITY INCREASED TO 1.7 GALS AND STAYED FOR QUITE A LONG TIME. IN THAT THE ENG HAD BEEN WORKED ON, RUN AND LEAK CHKED, I COULDN'T RULE OUT AN ERRONEOUS GAUGE AS WELL AS THE POSSIBILITY OF LOSS OF OIL. A PRECAUTIONARY REQUEST FOR DSCNT FROM FL390 TO FL350 WAS INITIATED AND UNAVAILABLE DUE TO AN ACR B FLT DIRECTLY BENEATH US AT FL370. HE WAS THEN VISUALLY SIGHTED. I NOTIFIED ATC THERE WAS THE POSSIBILITY OF AN ENG SHUTDOWN. I SPOKE WITH THE ACR B CREW AND ADVISED THEM THAT SHOULD IT BE NECESSARY, I WOULD LEAVE COURSE TO THE RIGHT BEFORE DSNDING. A PHONE PATCH WAS REQUESTED TO NRT DISPATCH--COULD NOT BE PUT THROUGH. TYO CTL SAID UNABLE. MSP DISPATCH WAS CONTACTED AND WE DISCUSSED THE SITUATION AND I WAS TOLD TO STANDBY WHILE THE DISPATCHER TRIED TO CONTACT NRT (NO CONTACT). I WAS GIVEN A RELEASE BACK TO NRT, BUT IN THAT THE QUANTITY HAD BEEN STABLE FOR QUITE A WHILE, WE CONCURRED TO CONTINUE (TYO DISPATCH LATER CONCURRED). THE QUANTITY DROPPED TO 1 GAL AND THEN RETURNED TO 1.2 GALS AND STAYED THERE QUITE A WHILE. WE HAD COMPUTED AN ETP (4 ENG) AND ADDITIONALLY DETERMINED THAT WE COULD MAINTAIN FL330 SHOULD A SHUT DOWN BECOME NECESSARY. THE ADDITIONAL FUEL BURN WOULD BE APPROX EQUIVALENT TO OUR PLUS FIGURE ON THE FUEL SCORE. THE GAUGE BEGAN TO DROP TO LESS THAN 1 GAL. I HAD NOTED THAT THE PREVIOUS FLT HAD LOW PRESSURE INDICATIONS AT .75 GALS. AT .6 GALS INDICATED, BOTH PRESSURE AND TEMP WERE ALL INDICATING NORMAL. APPROX 350 MI PAST THE ETP, THE LOW OIL PRESSURE LIGHT FLICKERED DIMLY, OIL PRESSURE STILL 49 PSI (I BELIEVE). I ELECTED TO EXERCISE MY EMER AUTHORITY, LEAVE TRACK TO THE RIGHT AND PARALLEL 25 NM. ACR B WAS VISUALLY A FEW MI IN FRONT OF US. I DSNDED TO FL335 PER CONTINGENCY INSTRUCTIONS. ENG WAS SHUT DOWN AT XE37Z FOR PRECAUTIONARY PURPOSES WHILE OIL WAS STILL IN TANK FOR WINDMILLING QUANTITY AND PRESSURE. ATC ADVISED THAT ACR B WAS THE ONLY TFC WE HAD. WE WERE UNABLE TO MAINTAIN CHART SPD WITH CHART PWR, SO DSNDED FROM FL330 TO FL310. ATC GAVE US A BLOCK ALT OF FL290/310. MIDWAY ISLAND WAS CONSIDERED, BUT DUE TO LACK OF FAMILIARITY, DARKNESS AND THE FACT HNL WAS CLEAR AND WE WOULD BE ARRIVING AT A FAMILIAR ARPT IN DAYLIGHT AND FUEL WAS NOT CRITICAL, THE DECISION WAS MADE TO CONTINUE. #3 ENG WAS CARRYING POSITIVE PRESSURE AND SUPPLY AND ALL OTHER SYSTEMS WERE NORMAL. DISPATCH CALLED WITH FUEL CALCULATIONS AND ALSO ADVISED THE COMPUTER SHOWED WE SHOULD BE AT FL290, SO I TOOK ADVANTAGE OF THE BLOCK CLRNC DSNDING TO FL290 AND ADVISED ATC OF THE CHANGE. THE REMAINDER OF THE FLT WAS UNEVENTFUL AND WE BLOCKED INTO HNL AT XI09Z WITH 25000# OF FUEL ON BOARD. RUNNING FUEL CALCULATIONS WERE MADE BY ME AND NEVER LESS THAN 24480# WAS PLANNED ON ARR. THE EMER EQUIP WAS ASKED FOR ON LNDG AS A PRECAUTIONARY MEASURE AND ALLOWED TO SECURE AFTER AN UNEVENTFUL LNDG. IT MAY BE ONLY PERCEPTION, BUT THE OIL GAUGE APPEARED TO DECREASE MORE NOTICEABLE AFTER THE SECOND TIME IT SHOWED 1 GAL REMAINING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR SAID THAT IT WAS POSSIBLE TO MAINTAIN FL330, BUT THAT THE FUEL FLOW REQUIRED TO DO SO WAS HIGHER THAN CHARTED. THE ADVICE TO DSND TO FL290 GIVEN BY DISPATCH WAS TO PROVIDE THE LOWEST FUEL BURNOUT TO DEST. RPTR SAID THAT HE HAD TO DECLARE AN EMER IN ORDER TO DSND, BUT THAT AS SOON AS HE GOT BELOW ACR B HE WAS GIVEN A HARD ALT AND PUT BACK ON TRACK BY ARTCC. RPTR SAID HE HAD BEEN TOLD THAT THE CAUSE OF THE OIL LEAK WAS A NUMBER OF MINOR SEAL LEAKS--THE SAME ONES THAT HAD BEEN WORKED ON BY MAINT IN JAPAN.
Data retrieved from NASA's ASRS site as of August 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.