Narrative:

On feb/xa/00, mechanic abc and myself taxied aircraft xyz from the international hardstand area to gate xb. Upon attempting to start the #1 engine, no rotation was observed. After arriving at gate xb, we again tried to manually start the #1 engine. Again, no rotation was observed, which led us to change the engine starter. We proceeded to change the starter according to the maintenance manual. To the best of our knowledge during the time of the change, all components related to the change appeared to be in good working order. As a precaution, the start valve was also replaced at this time. An operational check of the system proved to be ok. No defects or leaks noted. We proceeded to document our work accomplished. We later learned that flight yx returned to ZZZ due to oil loss indications on the #1 engine. Callback conversation with reporter revealed the following information: the reporter stated the #1 engine starter and starter valve were replaced per the maintenance manual and an operational check was accomplished on the gate. The reporter stated no leaks were noted on the idle engine run. The reporter said that when the aircraft returned, it was discovered that the starter drive seal was damaged, allowing the engine oil loss. Callback conversation with reporter of acn 462933 revealed the following information: the reporter stated the starter was replaced and checked per the maintenance manual and checked ok. The reporter said no leaks were observed on the engine idle run on the gate. The reporter said the cause of the oil leak is reported to be a cut seal on the starter drive. Callback conversation with reporter of acn 462481 revealed the following information: the reporter said the aircraft was a B767-300ER with general electric cf-6 80A engines. The reporter stated the loss of oil was very slow and at first thought to be an oil quantity indication problem. But as time passed, it was obvious it was leaking and would require the engine being shut down. The reporter said the maintenance report on the cause of the oil loss was a damaged oil drive seal.

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Original NASA ASRS Text

Title: A B767-300ER AT CRUISE DECLARES AN EMER AND DIVERTS DUE TO LOSS OF OIL PRESSURE AND QUANTITY CAUSED BY A DAMAGED #1 ENG STARTER DRIVE SEAL.

Narrative: ON FEB/XA/00, MECHANIC ABC AND MYSELF TAXIED ACFT XYZ FROM THE INTL HARDSTAND AREA TO GATE XB. UPON ATTEMPTING TO START THE #1 ENG, NO ROTATION WAS OBSERVED. AFTER ARRIVING AT GATE XB, WE AGAIN TRIED TO MANUALLY START THE #1 ENG. AGAIN, NO ROTATION WAS OBSERVED, WHICH LED US TO CHANGE THE ENG STARTER. WE PROCEEDED TO CHANGE THE STARTER ACCORDING TO THE MAINT MANUAL. TO THE BEST OF OUR KNOWLEDGE DURING THE TIME OF THE CHANGE, ALL COMPONENTS RELATED TO THE CHANGE APPEARED TO BE IN GOOD WORKING ORDER. AS A PRECAUTION, THE START VALVE WAS ALSO REPLACED AT THIS TIME. AN OPERATIONAL CHECK OF THE SYS PROVED TO BE OK. NO DEFECTS OR LEAKS NOTED. WE PROCEEDED TO DOCUMENT OUR WORK ACCOMPLISHED. WE LATER LEARNED THAT FLT YX RETURNED TO ZZZ DUE TO OIL LOSS INDICATIONS ON THE #1 ENG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE #1 ENG STARTER AND STARTER VALVE WERE REPLACED PER THE MAINT MANUAL AND AN OPERATIONAL CHECK WAS ACCOMPLISHED ON THE GATE. THE RPTR STATED NO LEAKS WERE NOTED ON THE IDLE ENG RUN. THE RPTR SAID THAT WHEN THE ACFT RETURNED, IT WAS DISCOVERED THAT THE STARTER DRIVE SEAL WAS DAMAGED, ALLOWING THE ENG OIL LOSS. CALLBACK CONVERSATION WITH RPTR OF ACN 462933 REVEALED THE FOLLOWING INFO: THE RPTR STATED THE STARTER WAS REPLACED AND CHECKED PER THE MAINT MANUAL AND CHECKED OK. THE RPTR SAID NO LEAKS WERE OBSERVED ON THE ENG IDLE RUN ON THE GATE. THE RPTR SAID THE CAUSE OF THE OIL LEAK IS REPORTED TO BE A CUT SEAL ON THE STARTER DRIVE. CALLBACK CONVERSATION WITH RPTR OF ACN 462481 REVEALED THE FOLLOWING INFO: THE RPTR SAID THE ACFT WAS A B767-300ER WITH GENERAL ELECTRIC CF-6 80A ENGINES. THE RPTR STATED THE LOSS OF OIL WAS VERY SLOW AND AT FIRST THOUGHT TO BE AN OIL QUANTITY INDICATION PROB. BUT AS TIME PASSED, IT WAS OBVIOUS IT WAS LEAKING AND WOULD REQUIRE THE ENG BEING SHUT DOWN. THE RPTR SAID THE MAINT RPT ON THE CAUSE OF THE OIL LOSS WAS A DAMAGED OIL DRIVE SEAL.

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.