Narrative:

I was aware by local management that an aileron bus cable on aircraft XXX had broken. After 'review' of the paperwork it was confirmed that my signature was on the install paperwork. It was confirmed that during installation of the cable it was routed above the cable guide. In review of the work card used for this job it is apparent that each cable affected should have its own removal and installation signoff block. The paperwork also lacks having a step to remove and replace the cable guide. I feel that these clarifications in the paperwork would help in future mistakes or 'confusion.' supplemental information from acn 755326: on the shift in question; I was assigned the rigging and operations check of the new previously installed aileron bus cables. All cables were rigged and operations checked in accordance with all maintenance manuals and work cards. All operations checks were completed with no problems noted. During the installation procedures; of the aileron bus cables the paperwork should reflect the signoff for the removal and installation of the cable guide pin for the aileron quadrant. Due to the position of the aileron quadrant and pin location; it is easy to understand how this could have 'occurred' without a 'procedure' to remove and install guide pin. Callback conversation with reporter revealed the following information: reporter stated the aileron bus cable in the wheel well did not actually break as noted in the report. However; the cable was routed to the outside of; and above the pulley guide and eventually had bird-caged from chafing against that same pulley guide. The damaged cable was found approximately two months after installation during a winglet mod. Reporter also stated he is not aware; nor was he informed; about any flight control issues associated with the damaged cable. Furthermore; he did not actually install; or route that end of the shorter bus cable in the wheel well. Rather; he had swaged the terminal end of the longer connecting cable running in from the wing section. Problem was; he had signed off for the entire installation as a result of the way the paperwork was set-up. The original bus cable was changed for time during a routine 'C' check and the recent installed cable was the one that bird-caged due to misrouting.

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Original NASA ASRS Text

Title: A B737-500 NEW AILERON BUS CABLE BROKE SHORTLY AFTER BEING INSTALLED. CABLE HAD BEEN MIS-ROUTED AROUND A PULLEY GUIDE.

Narrative: I WAS AWARE BY LCL MGMNT THAT AN AILERON BUS CABLE ON ACFT XXX HAD BROKEN. AFTER 'REVIEW' OF THE PAPERWORK IT WAS CONFIRMED THAT MY SIGNATURE WAS ON THE INSTALL PAPERWORK. IT WAS CONFIRMED THAT DURING INSTALLATION OF THE CABLE IT WAS ROUTED ABOVE THE CABLE GUIDE. IN REVIEW OF THE WORK CARD USED FOR THIS JOB IT IS APPARENT THAT EACH CABLE AFFECTED SHOULD HAVE ITS OWN REMOVAL AND INSTALLATION SIGNOFF BLOCK. THE PAPERWORK ALSO LACKS HAVING A STEP TO REMOVE AND REPLACE THE CABLE GUIDE. I FEEL THAT THESE CLARIFICATIONS IN THE PAPERWORK WOULD HELP IN FUTURE MISTAKES OR 'CONFUSION.' SUPPLEMENTAL INFO FROM ACN 755326: ON THE SHIFT IN QUESTION; I WAS ASSIGNED THE RIGGING AND OPS CHK OF THE NEW PREVIOUSLY INSTALLED AILERON BUS CABLES. ALL CABLES WERE RIGGED AND OPS CHKED IN ACCORDANCE WITH ALL MAINT MANUALS AND WORK CARDS. ALL OPS CHKS WERE COMPLETED WITH NO PROBS NOTED. DURING THE INSTALLATION PROCS; OF THE AILERON BUS CABLES THE PAPERWORK SHOULD REFLECT THE SIGNOFF FOR THE REMOVAL AND INSTALLATION OF THE CABLE GUIDE PIN FOR THE AILERON QUADRANT. DUE TO THE POS OF THE AILERON QUADRANT AND PIN LOCATION; IT IS EASY TO UNDERSTAND HOW THIS COULD HAVE 'OCCURRED' WITHOUT A 'PROC' TO REMOVE AND INSTALL GUIDE PIN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE AILERON BUS CABLE IN THE WHEEL WELL DID NOT ACTUALLY BREAK AS NOTED IN THE REPORT. HOWEVER; THE CABLE WAS ROUTED TO THE OUTSIDE OF; AND ABOVE THE PULLEY GUIDE AND EVENTUALLY HAD BIRD-CAGED FROM CHAFING AGAINST THAT SAME PULLEY GUIDE. THE DAMAGED CABLE WAS FOUND APPROXIMATELY TWO MONTHS AFTER INSTALLATION DURING A WINGLET MOD. REPORTER ALSO STATED HE IS NOT AWARE; NOR WAS HE INFORMED; ABOUT ANY FLIGHT CONTROL ISSUES ASSOCIATED WITH THE DAMAGED CABLE. FURTHERMORE; HE DID NOT ACTUALLY INSTALL; OR ROUTE THAT END OF THE SHORTER BUS CABLE IN THE WHEEL WELL. RATHER; HE HAD SWAGED THE TERMINAL END OF THE LONGER CONNECTING CABLE RUNNING IN FROM THE WING SECTION. PROBLEM WAS; HE HAD SIGNED OFF FOR THE ENTIRE INSTALLATION AS A RESULT OF THE WAY THE PAPERWORK WAS SET-UP. THE ORIGINAL BUS CABLE WAS CHANGED FOR TIME DURING A ROUTINE 'C' CHECK AND THE RECENT INSTALLED CABLE WAS THE ONE THAT BIRD-CAGED DUE TO MISROUTING.

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.