Narrative:

This is an account of events and actions relating to the diversion of air carrier X on oct/mon/06 at XA00 hours. The company maintenance software program shows a logbook entry on oct/mon/06: 'during climb out and cruise flight #2 engine oil pressure showed rapid fluctuation and decrease in pressure. Crew verified oil leak #2 nacelle in-flight.' the corrective action by maintenance was entered as: 'inspected and found #2 generator (starter/generator) loose on pad. Re-secured and svced with 5 qts oil. Ran engine; still leaking from pad. Notified supervisor. Sending mechanics out of ZZZ1 with parts.' the corrective action follows as: 'right&right (removed and replaced) starter/generator garlock seal and starter/generator operations and leak check good per work card 24-30-02R.' in addition; the starter/generator 'V' band clamp was right&right'ed as well. I was the mechanic who accomplished the garlock seal right&right called for by the air traffic area chapter 79 entry dated sep/thu/06; 'replace starter/generator garlock seal.' it appears that incorrect maintenance procedures were followed. In the process of doing step 11 of work card 24-30-02R; I checked that the nut on the 'T' bolt of the V band clamp would not turn off of the end of the bolt; but did not verify the nut having full thread engagement when hand tightened. I did torque the V band clamp nut to 70 inch/pounds with my personal torque wrench. Also; in the process of step 12 of work card 24-30-02R inspection of the clamp is called for: '...by inspecting around the clamp using an inspection mirror as needed and by applying hand force to check for looseness.' my visual inspection of the outboard top of the clamp; outboard side and bottom of the clamp was done; but I felt that mirror inspection was not needed. Hand force was applied and no looseness was noted. The garlock seal right&right and the starter/generator right&right both passed leak check and operation check as required in work card 24-30-02R at step 16. In as much as the oil leak was noted during flight; the V bend clamp nut must have loosened during usage of the engine #2 between maintenance at ZZZ1 and XA00 hours next day. Upon inspection and re-securing the V band clamp; when leak/operations check was performed; 'oil still leaked from pad' necessitating a mechanic/parts road trip from ZZZ1. The final corrective action was to right&right both the garlock seal and the starter/generator as well as the V band clamp. In retrospect; I find that the requirements of work card 24-30-02R step 11 are vague in that the nut needs to have running torque for the length of the 'T' bolt; not just 'sufficient to prevent full thread engagement when hand tightened.' I will do so in the future when I right&right V band clamps of this nature.

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Original NASA ASRS Text

Title: A DHC8-100 DIVERTED DUE TO LOSS OF #2 ENG OIL PRESSURE AND QUANTITY. CAUSED BY IMPROPER INSTALLATION OF V BAND CLAMP DURING STARTER GENERATOR CHANGE.

Narrative: THIS IS AN ACCOUNT OF EVENTS AND ACTIONS RELATING TO THE DIVERSION OF ACR X ON OCT/MON/06 AT XA00 HRS. THE COMPANY MAINT SOFTWARE PROGRAM SHOWS A LOGBOOK ENTRY ON OCT/MON/06: 'DURING CLBOUT AND CRUISE FLT #2 ENG OIL PRESSURE SHOWED RAPID FLUCTUATION AND DECREASE IN PRESSURE. CREW VERIFIED OIL LEAK #2 NACELLE INFLT.' THE CORRECTIVE ACTION BY MAINT WAS ENTERED AS: 'INSPECTED AND FOUND #2 GENERATOR (STARTER/GENERATOR) LOOSE ON PAD. RE-SECURED AND SVCED WITH 5 QTS OIL. RAN ENG; STILL LEAKING FROM PAD. NOTIFIED SUPVR. SENDING MECHS OUT OF ZZZ1 WITH PARTS.' THE CORRECTIVE ACTION FOLLOWS AS: 'R&R (REMOVED AND REPLACED) STARTER/GENERATOR GARLOCK SEAL AND STARTER/GENERATOR OPS AND LEAK CHK GOOD PER WORK CARD 24-30-02R.' IN ADDITION; THE STARTER/GENERATOR 'V' BAND CLAMP WAS R&R'ED AS WELL. I WAS THE MECH WHO ACCOMPLISHED THE GARLOCK SEAL R&R CALLED FOR BY THE ATA CHAPTER 79 ENTRY DATED SEP/THU/06; 'REPLACE STARTER/GENERATOR GARLOCK SEAL.' IT APPEARS THAT INCORRECT MAINT PROCS WERE FOLLOWED. IN THE PROCESS OF DOING STEP 11 OF WORK CARD 24-30-02R; I CHKED THAT THE NUT ON THE 'T' BOLT OF THE V BAND CLAMP WOULD NOT TURN OFF OF THE END OF THE BOLT; BUT DID NOT VERIFY THE NUT HAVING FULL THREAD ENGAGEMENT WHEN HAND TIGHTENED. I DID TORQUE THE V BAND CLAMP NUT TO 70 INCH/LBS WITH MY PERSONAL TORQUE WRENCH. ALSO; IN THE PROCESS OF STEP 12 OF WORK CARD 24-30-02R INSPECTION OF THE CLAMP IS CALLED FOR: '...BY INSPECTING AROUND THE CLAMP USING AN INSPECTION MIRROR AS NEEDED AND BY APPLYING HAND FORCE TO CHK FOR LOOSENESS.' MY VISUAL INSPECTION OF THE OUTBOARD TOP OF THE CLAMP; OUTBOARD SIDE AND BOTTOM OF THE CLAMP WAS DONE; BUT I FELT THAT MIRROR INSPECTION WAS NOT NEEDED. HAND FORCE WAS APPLIED AND NO LOOSENESS WAS NOTED. THE GARLOCK SEAL R&R AND THE STARTER/GENERATOR R&R BOTH PASSED LEAK CHK AND OP CHK AS REQUIRED IN WORK CARD 24-30-02R AT STEP 16. IN AS MUCH AS THE OIL LEAK WAS NOTED DURING FLT; THE V BEND CLAMP NUT MUST HAVE LOOSENED DURING USAGE OF THE ENG #2 BTWN MAINT AT ZZZ1 AND XA00 HRS NEXT DAY. UPON INSPECTION AND RE-SECURING THE V BAND CLAMP; WHEN LEAK/OPS CHK WAS PERFORMED; 'OIL STILL LEAKED FROM PAD' NECESSITATING A MECH/PARTS ROAD TRIP FROM ZZZ1. THE FINAL CORRECTIVE ACTION WAS TO R&R BOTH THE GARLOCK SEAL AND THE STARTER/GENERATOR AS WELL AS THE V BAND CLAMP. IN RETROSPECT; I FIND THAT THE REQUIREMENTS OF WORK CARD 24-30-02R STEP 11 ARE VAGUE IN THAT THE NUT NEEDS TO HAVE RUNNING TORQUE FOR THE LENGTH OF THE 'T' BOLT; NOT JUST 'SUFFICIENT TO PREVENT FULL THREAD ENGAGEMENT WHEN HAND TIGHTENED.' I WILL DO SO IN THE FUTURE WHEN I R&R V BAND CLAMPS OF THIS NATURE.

Data retrieved from NASA's ASRS site as of January 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.