Narrative:

Upon receiving the job assignment of troubleshooting and repairing recirculation fan, I first wanted to perform a visual examination of the recirculation fan. The subsequent examination revealed no obvious visual defects to the component. I was able to hand turn the fan assembly. I experienced no smokey or burnt smell one would expect under these circumstances. I reinstalled and performed an operations check of the recirculation fan and observed normal operations. When I began troubleshooting this MEL, the recirculation fan circuit breakers were in. At no time while the recirculation fan circuit breakers were pulled for my removal and visual examination, or when the recirculation fan circuit breakers were re-set for my operations check of the recirculation fan, did I observe any circuit breaker collars. While MEL 21-31 does not require the installation of circuit breaker collars, I did make note of the fact that on log page contract maintenance stated 'breakers pulled and collared.' as I stated previously, there were no circuit breaker collars installed, and the recirculation fan circuit breakers were pushed in upon my initial contact with this aircraft. My subsequent troubleshooting led me to remove and replace the gasper fan, and my signoff on deferred maintenance log page attests to the normal operations of both the recirculation and gasper fans. Moreover, copies of log pages provide to me totaling 2 days and 15 flight legs do not show any reported discrepancies with the recirculation or gasper fans. Questions from FAA inspector concerning the restoration of the aircraft are well founded. However, I am not able to state in my corrective actions that I removed any circuit breaker collars when no collars were ever installed. Additionally, on dec/wed/04, line mechanics were asked to inspect the aircraft for tie-wraps, not circuit breaker collars. Moreover, the tie-wraps that have been shown to me as what was removed from the recirculation fan circuit breakers on dec/wed/04 are not tie-wraps at all! A more accurate description would be tamper seals. These tamper seals are of a diameter and thickness so small that they would not prevent a circuit breaker from being reset. In conclusion, I can see that the importance of 'attention to detail' can easily be overlooked when the job gets more involved. I had become so involved in finding the real truth of which fan was really at fault that I skipped a simple step of a close look of the circuit breaker panel to see that everything was as it should be. A simple post job review of my work area and any related paperwork would have prevented all of this.

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Original NASA ASRS Text

Title: A B737 RECIRCULATION FAN WAS REPLACED AND OPERATED FOR SEVERAL DAYS WHEN AN FAA SAFETY INSPECTOR RPTED FINDING TIE-WRAPS COLLARING THE FAN CIRCUIT BREAKERS.

Narrative: UPON RECEIVING THE JOB ASSIGNMENT OF TROUBLESHOOTING AND REPAIRING RECIRCULATION FAN, I FIRST WANTED TO PERFORM A VISUAL EXAM OF THE RECIRCULATION FAN. THE SUBSEQUENT EXAM REVEALED NO OBVIOUS VISUAL DEFECTS TO THE COMPONENT. I WAS ABLE TO HAND TURN THE FAN ASSEMBLY. I EXPERIENCED NO SMOKEY OR BURNT SMELL ONE WOULD EXPECT UNDER THESE CIRCUMSTANCES. I REINSTALLED AND PERFORMED AN OPS CHK OF THE RECIRCULATION FAN AND OBSERVED NORMAL OPS. WHEN I BEGAN TROUBLESHOOTING THIS MEL, THE RECIRCULATION FAN CIRCUIT BREAKERS WERE IN. AT NO TIME WHILE THE RECIRCULATION FAN CIRCUIT BREAKERS WERE PULLED FOR MY REMOVAL AND VISUAL EXAM, OR WHEN THE RECIRCULATION FAN CIRCUIT BREAKERS WERE RE-SET FOR MY OPS CHK OF THE RECIRCULATION FAN, DID I OBSERVE ANY CIRCUIT BREAKER COLLARS. WHILE MEL 21-31 DOES NOT REQUIRE THE INSTALLATION OF CIRCUIT BREAKER COLLARS, I DID MAKE NOTE OF THE FACT THAT ON LOG PAGE CONTRACT MAINT STATED 'BREAKERS PULLED AND COLLARED.' AS I STATED PREVIOUSLY, THERE WERE NO CIRCUIT BREAKER COLLARS INSTALLED, AND THE RECIRCULATION FAN CIRCUIT BREAKERS WERE PUSHED IN UPON MY INITIAL CONTACT WITH THIS ACFT. MY SUBSEQUENT TROUBLESHOOTING LED ME TO REMOVE AND REPLACE THE GASPER FAN, AND MY SIGNOFF ON DEFERRED MAINT LOG PAGE ATTESTS TO THE NORMAL OPS OF BOTH THE RECIRCULATION AND GASPER FANS. MOREOVER, COPIES OF LOG PAGES PROVIDE TO ME TOTALING 2 DAYS AND 15 FLT LEGS DO NOT SHOW ANY RPTED DISCREPANCIES WITH THE RECIRCULATION OR GASPER FANS. QUESTIONS FROM FAA INSPECTOR CONCERNING THE RESTORATION OF THE ACFT ARE WELL FOUNDED. HOWEVER, I AM NOT ABLE TO STATE IN MY CORRECTIVE ACTIONS THAT I REMOVED ANY CIRCUIT BREAKER COLLARS WHEN NO COLLARS WERE EVER INSTALLED. ADDITIONALLY, ON DEC/WED/04, LINE MECHS WERE ASKED TO INSPECT THE ACFT FOR TIE-WRAPS, NOT CIRCUIT BREAKER COLLARS. MOREOVER, THE TIE-WRAPS THAT HAVE BEEN SHOWN TO ME AS WHAT WAS REMOVED FROM THE RECIRCULATION FAN CIRCUIT BREAKERS ON DEC/WED/04 ARE NOT TIE-WRAPS AT ALL! A MORE ACCURATE DESCRIPTION WOULD BE TAMPER SEALS. THESE TAMPER SEALS ARE OF A DIAMETER AND THICKNESS SO SMALL THAT THEY WOULD NOT PREVENT A CIRCUIT BREAKER FROM BEING RESET. IN CONCLUSION, I CAN SEE THAT THE IMPORTANCE OF 'ATTN TO DETAIL' CAN EASILY BE OVERLOOKED WHEN THE JOB GETS MORE INVOLVED. I HAD BECOME SO INVOLVED IN FINDING THE REAL TRUTH OF WHICH FAN WAS REALLY AT FAULT THAT I SKIPPED A SIMPLE STEP OF A CLOSE LOOK OF THE CIRCUIT BREAKER PANEL TO SEE THAT EVERYTHING WAS AS IT SHOULD BE. A SIMPLE POST JOB REVIEW OF MY WORK AREA AND ANY RELATED PAPERWORK WOULD HAVE PREVENTED ALL OF THIS.

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.