Narrative:

Myself and a fellow amt were assigned to work aircraft. After performing an ETOPS reliability check; I assisted amt in preparing the #1 engine for a borescope inspection. During the preparation; I removed the gear box crank pad cover so that the engine could be turned for the inspection. At that point; my shift came to an end; leaving the other amt to finish the task. I was notified at around XA30 that the aircraft had taken off and lost oil pressure and quantity. The aircraft then performed a #1 engine in-flight shutdown and an air turn-back. After inspecting the engine; it was found that the crank pad cover was not reinstalled. A lack of communication between the amt and myself; job turnover were probably the key factors in this event. I neglected to tell the amt where I had placed the removed crank pad cover. Supplemental information from acn 787494: I started a borescope inspection on the #1 engine. I removed the borescope plugs. My partner assisted me on the borescope by removing the crank pad. His shift came to an end and he left without telling me where he put the crank pad. It was about 2 or 2 1/2 hours before inspection came to inspect the engine. I put the borescope plugs I removed on the ground next to my tools under the engine. I installed them and had someone else check behind me. We both missed the crank pad. The crank pad is behind oil drain line and is not easy to see. We signed paperwork saying we complied with inspection. We leak checked engine and found no leaks. The paperwork does not state that we had to open thrust reverser cowls back up. I suggest a streamer be left from the crank pad while removed and a sign block for the thrust reversers to be opened back up and looked at after engine run. Supplemental information from acn 787486: I missed that the crank pad cover was not installed. Being dark outside and lack of a more detailed inspection contributed. Callback conversation with reporter revealed the following information: reporter stated he hasn't seen any changes to the borescope open-up job card at this time; regarding the crank pad cover installation or the engine run oil leak check procedure.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B767 REQUIRED AN AIR TURN BACK AFTER #1 ENG LOSS OIL PRESSURE AND QUANTITY; DUE TO CRANK PAD COVER NOT REINSTALLED AFTER BORESCOPE INSPECTION.

Narrative: MYSELF AND A FELLOW AMT WERE ASSIGNED TO WORK ACFT. AFTER PERFORMING AN ETOPS RELIABILITY CHK; I ASSISTED AMT IN PREPARING THE #1 ENG FOR A BORESCOPE INSPECTION. DURING THE PREPARATION; I REMOVED THE GEAR BOX CRANK PAD COVER SO THAT THE ENG COULD BE TURNED FOR THE INSPECTION. AT THAT POINT; MY SHIFT CAME TO AN END; LEAVING THE OTHER AMT TO FINISH THE TASK. I WAS NOTIFIED AT AROUND XA30 THAT THE ACFT HAD TAKEN OFF AND LOST OIL PRESSURE AND QUANTITY. THE ACFT THEN PERFORMED A #1 ENG INFLT SHUTDOWN AND AN AIR TURN-BACK. AFTER INSPECTING THE ENG; IT WAS FOUND THAT THE CRANK PAD COVER WAS NOT REINSTALLED. A LACK OF COM BTWN THE AMT AND MYSELF; JOB TURNOVER WERE PROBABLY THE KEY FACTORS IN THIS EVENT. I NEGLECTED TO TELL THE AMT WHERE I HAD PLACED THE REMOVED CRANK PAD COVER. SUPPLEMENTAL INFO FROM ACN 787494: I STARTED A BORESCOPE INSPECTION ON THE #1 ENG. I REMOVED THE BORESCOPE PLUGS. MY PARTNER ASSISTED ME ON THE BORESCOPE BY REMOVING THE CRANK PAD. HIS SHIFT CAME TO AN END AND HE LEFT WITHOUT TELLING ME WHERE HE PUT THE CRANK PAD. IT WAS ABOUT 2 OR 2 1/2 HRS BEFORE INSPECTION CAME TO INSPECT THE ENG. I PUT THE BORESCOPE PLUGS I REMOVED ON THE GND NEXT TO MY TOOLS UNDER THE ENG. I INSTALLED THEM AND HAD SOMEONE ELSE CHK BEHIND ME. WE BOTH MISSED THE CRANK PAD. THE CRANK PAD IS BEHIND OIL DRAIN LINE AND IS NOT EASY TO SEE. WE SIGNED PAPERWORK SAYING WE COMPLIED WITH INSPECTION. WE LEAK CHKED ENG AND FOUND NO LEAKS. THE PAPERWORK DOES NOT STATE THAT WE HAD TO OPEN THRUST REVERSER COWLS BACK UP. I SUGGEST A STREAMER BE LEFT FROM THE CRANK PAD WHILE REMOVED AND A SIGN BLOCK FOR THE THRUST REVERSERS TO BE OPENED BACK UP AND LOOKED AT AFTER ENG RUN. SUPPLEMENTAL INFO FROM ACN 787486: I MISSED THAT THE CRANK PAD COVER WAS NOT INSTALLED. BEING DARK OUTSIDE AND LACK OF A MORE DETAILED INSPECTION CONTRIBUTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED HE HASN'T SEEN ANY CHANGES TO THE BORESCOPE OPEN-UP JOB CARD AT THIS TIME; REGARDING THE CRANK PAD COVER INSTALLATION OR THE ENGINE RUN OIL LEAK CHECK PROCEDURE.

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.