Narrative:

The aircraft arrived in seoul with a log write-up indicating that the #3 l-hand hydraulic pressure low light on, and that system pressure indicated normal. Seoul troubleshot the #3 engine l-hand hydraulic pump problem and found that the input shaft had been sheared. Air carrier a MEL requires that an inoperative hydraulic pump must either be replaced, or have the pump removed and a blanking plate installed. Air carrier a did not stock a svcable pump in seoul, and also did not have a blanking kit available. Seoul placed a call to air carrier B, to see if they had a svcable pump that air carrier a could borrow. The only hydraulic pump that air carrier B stocks, is a X pump, which air carrier a no longer uses, but is still an acceptable pump to use. I gave the authority/authorized to seoul to use the X pump from air carrier B and to create a deferred item to have pump replaced at the earliest maintenance opportunity. Also available to seoul was maintenance manual reference that contains information regarding the removal and installation of an X hydraulic pump. Seoul completed the replacement of the hydraulic pump, leak checked the pump installation, and made the necessary deferred items to have the pump removed. Flight departed seoul. After takeoff, received ACARS message from crew that they were losing engine oil from the #3 engine. The flight crew pulled and reset circuit breaker for #3 engine oil quantity indicator, with no change in the condition. I sent the crew an ACARS message indicating that I believed the indicator was indicating correctly, and what they were probably losing engine oil from the #3 engine. I instructed the crew to follow the procedures in their flight manual, and to be prepared to shutdown the #3 engine if they lost oil pressure. Shortly after that, received message from crew that the oil quantity was now reading zero, but pressure was still good. Flight landed in narita, japan, with the #3 engine still running. However, the #3 engine oil pressure indication began fluctuating, and the crew elected to shutdown the engine on taxi-in. I had contacted maintenance in narita and informed them prior to landing that the #3 engine was losing oil, and that I believed the problem was with the #3 l-hand hydraulic pump that was just installed. After the aircraft had taxied in, narita removed the pump and found that the pump had been installed without the drive spline o-ring installed. Narita then installed the blanking plate kit per the MEL, and resvced the engine oil.

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Original NASA ASRS Text

Title: AN ACR WDB HAD TO DIVERT LAND AFTER AN IMPROPER MAINT PROC.

Narrative: THE ACFT ARRIVED IN SEOUL WITH A LOG WRITE-UP INDICATING THAT THE #3 L-HAND HYD PRESSURE LOW LIGHT ON, AND THAT SYS PRESSURE INDICATED NORMAL. SEOUL TROUBLESHOT THE #3 ENG L-HAND HYD PUMP PROB AND FOUND THAT THE INPUT SHAFT HAD BEEN SHEARED. ACR A MEL REQUIRES THAT AN INOP HYD PUMP MUST EITHER BE REPLACED, OR HAVE THE PUMP REMOVED AND A BLANKING PLATE INSTALLED. ACR A DID NOT STOCK A SVCABLE PUMP IN SEOUL, AND ALSO DID NOT HAVE A BLANKING KIT AVAILABLE. SEOUL PLACED A CALL TO ACR B, TO SEE IF THEY HAD A SVCABLE PUMP THAT ACR A COULD BORROW. THE ONLY HYD PUMP THAT ACR B STOCKS, IS A X PUMP, WHICH ACR A NO LONGER USES, BUT IS STILL AN ACCEPTABLE PUMP TO USE. I GAVE THE AUTH TO SEOUL TO USE THE X PUMP FROM ACR B AND TO CREATE A DEFERRED ITEM TO HAVE PUMP REPLACED AT THE EARLIEST MAINT OPPORTUNITY. ALSO AVAILABLE TO SEOUL WAS MAINT MANUAL REF THAT CONTAINS INFO REGARDING THE REMOVAL AND INSTALLATION OF AN X HYD PUMP. SEOUL COMPLETED THE REPLACEMENT OF THE HYD PUMP, LEAK CHKED THE PUMP INSTALLATION, AND MADE THE NECESSARY DEFERRED ITEMS TO HAVE THE PUMP REMOVED. FLT DEPARTED SEOUL. AFTER TKOF, RECEIVED ACARS MESSAGE FROM CREW THAT THEY WERE LOSING ENG OIL FROM THE #3 ENG. THE FLC PULLED AND RESET CIRCUIT BREAKER FOR #3 ENG OIL QUANTITY INDICATOR, WITH NO CHANGE IN THE CONDITION. I SENT THE CREW AN ACARS MESSAGE INDICATING THAT I BELIEVED THE INDICATOR WAS INDICATING CORRECTLY, AND WHAT THEY WERE PROBABLY LOSING ENG OIL FROM THE #3 ENG. I INSTRUCTED THE CREW TO FOLLOW THE PROCS IN THEIR FLT MANUAL, AND TO BE PREPARED TO SHUTDOWN THE #3 ENG IF THEY LOST OIL PRESSURE. SHORTLY AFTER THAT, RECEIVED MESSAGE FROM CREW THAT THE OIL QUANTITY WAS NOW READING ZERO, BUT PRESSURE WAS STILL GOOD. FLT LANDED IN NARITA, JAPAN, WITH THE #3 ENG STILL RUNNING. HOWEVER, THE #3 ENG OIL PRESSURE INDICATION BEGAN FLUCTUATING, AND THE CREW ELECTED TO SHUTDOWN THE ENG ON TAXI-IN. I HAD CONTACTED MAINT IN NARITA AND INFORMED THEM PRIOR TO LNDG THAT THE #3 ENG WAS LOSING OIL, AND THAT I BELIEVED THE PROB WAS WITH THE #3 L-HAND HYD PUMP THAT WAS JUST INSTALLED. AFTER THE ACFT HAD TAXIED IN, NARITA REMOVED THE PUMP AND FOUND THAT THE PUMP HAD BEEN INSTALLED WITHOUT THE DRIVE SPLINE O-RING INSTALLED. NARITA THEN INSTALLED THE BLANKING PLATE KIT PER THE MEL, AND RESVCED THE ENG OIL.

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.