Narrative:

Flight crew arrived at airport approximately 45 mins before departure. First officer proceeded to the aircraft to begin preflight and I went to gather the flight paperwork. I noted that our #1 thrust reverser was on MEL. I arrive at the aircraft to a relatively dark flight deck where I stowed my gear and sat down in my seat. I viewed the logbook that the first officer had left in my seat noting that there were no open discrepancies since the last airworthiness release was signed. The aircraft met all the requirements listed for the thrust reverser MEL. We flew the aircraft to ZZZ where we switched to another aircraft for the remainder of our flts. Upon our return to ZZZ later that afternoon I was informed that we had flown an aircraft with a pulled circuit breaker. This was my first indication that an event had occurred. I believe that my first officer (and previous first officer's) did indeed look over the circuit breaker panel but missed the tag possibly because of the location and dark atmosphere of the flight deck. Since this seems to be a recurring event I feel there are some steps that could and should be taken to help minimize the chance of another recurrence. 1) logbook entry by maintenance that circuit breakers have been pulled for a procedure. 2) some type of control yoke or thrust lever placard when this type of maintenance is being performed. 3) train how to look at circuit breakers. Seats may need to be moved; bags may get in the way; each row must be looked at; etc. 4) the captain does not normally look at the circuit breakers. Maybe capts should include a scan of the circuit breaker panels on their preflight as well. As my own procedure I will start looking over the P18 circuit breaker panel when I stow my flight bag making it a point to slide my seat up and stow it from behind. Then I will look at the P6 circuit breaker panel (behind first officer seat). I then will situation down and as I do now; look over the logbook. Supplemental information from acn 813501: aircraft arrived via maintenance taxi from hangar push minus 30 mins. On preflight inspection; drain mast circuit breaker was discovered open and tagged by maintenance. Based on my experience level and lack of ground training on distinguishing between maintenance tags; I assumed maintenance had the circuit breaker tagged and was properly documented. An unrelated MEL with the a hydraulic system and #1 reverser distraction me from bringing the circuit breaker up to the captain. I believe I had inadequate training to identification the safety tag from other flyable tags. Additionally; I negative xfer occurred from another carrier who color codes circuit breaker tags based on function; ie; white is ok; yellow is caution; red (and large) is remove before flight. The tag in question was white. Factors involved include the distraction by the hydraulic MEL; the late arrival of the aircraft at the gate; similar looking 'tags;' and incomplete maintenance post taxi procedures. Color code tags. If maintenance colors a non-flyable breaker that is not an MEL (and documented); it should be a bold color in danger colors of red or yellow. White is a 'normal' condition color for flight deck purposes (ie; ng displays). Initial IOE training should point out the difference of tags and their importance during preflight inspection training. Maintenance procedures should have written guidance to scan circuit breakers prior to releasing to flight crews.

Google
 

Original NASA ASRS Text

Title: A FLIGHT CREW MISSED AN OPEN CIRCUIT BREAKER ON PREFLIGHT AND FLEW A FLIGHT IN AN ILLEGAL CONFIGURATION.

Narrative: FLT CREW ARRIVED AT ARPT APPROX 45 MINS BEFORE DEP. FO PROCEEDED TO THE ACFT TO BEGIN PREFLT AND I WENT TO GATHER THE FLT PAPERWORK. I NOTED THAT OUR #1 THRUST REVERSER WAS ON MEL. I ARRIVE AT THE ACFT TO A RELATIVELY DARK FLT DECK WHERE I STOWED MY GEAR AND SAT DOWN IN MY SEAT. I VIEWED THE LOGBOOK THAT THE FO HAD LEFT IN MY SEAT NOTING THAT THERE WERE NO OPEN DISCREPANCIES SINCE THE LAST AIRWORTHINESS RELEASE WAS SIGNED. THE ACFT MET ALL THE REQUIREMENTS LISTED FOR THE THRUST REVERSER MEL. WE FLEW THE ACFT TO ZZZ WHERE WE SWITCHED TO ANOTHER ACFT FOR THE REMAINDER OF OUR FLTS. UPON OUR RETURN TO ZZZ LATER THAT AFTERNOON I WAS INFORMED THAT WE HAD FLOWN AN ACFT WITH A PULLED CIRCUIT BREAKER. THIS WAS MY FIRST INDICATION THAT AN EVENT HAD OCCURRED. I BELIEVE THAT MY FO (AND PREVIOUS FO'S) DID INDEED LOOK OVER THE CIRCUIT BREAKER PANEL BUT MISSED THE TAG POSSIBLY BECAUSE OF THE LOCATION AND DARK ATMOSPHERE OF THE FLT DECK. SINCE THIS SEEMS TO BE A RECURRING EVENT I FEEL THERE ARE SOME STEPS THAT COULD AND SHOULD BE TAKEN TO HELP MINIMIZE THE CHANCE OF ANOTHER RECURRENCE. 1) LOGBOOK ENTRY BY MAINT THAT CIRCUIT BREAKERS HAVE BEEN PULLED FOR A PROC. 2) SOME TYPE OF CTL YOKE OR THRUST LEVER PLACARD WHEN THIS TYPE OF MAINT IS BEING PERFORMED. 3) TRAIN HOW TO LOOK AT CIRCUIT BREAKERS. SEATS MAY NEED TO BE MOVED; BAGS MAY GET IN THE WAY; EACH ROW MUST BE LOOKED AT; ETC. 4) THE CAPT DOES NOT NORMALLY LOOK AT THE CIRCUIT BREAKERS. MAYBE CAPTS SHOULD INCLUDE A SCAN OF THE CIRCUIT BREAKER PANELS ON THEIR PREFLT AS WELL. AS MY OWN PROC I WILL START LOOKING OVER THE P18 CIRCUIT BREAKER PANEL WHEN I STOW MY FLT BAG MAKING IT A POINT TO SLIDE MY SEAT UP AND STOW IT FROM BEHIND. THEN I WILL LOOK AT THE P6 CIRCUIT BREAKER PANEL (BEHIND FO SEAT). I THEN WILL SIT DOWN AND AS I DO NOW; LOOK OVER THE LOGBOOK. SUPPLEMENTAL INFO FROM ACN 813501: ACFT ARRIVED VIA MAINT TAXI FROM HANGAR PUSH MINUS 30 MINS. ON PREFLT INSPECTION; DRAIN MAST CIRCUIT BREAKER WAS DISCOVERED OPEN AND TAGGED BY MAINT. BASED ON MY EXPERIENCE LEVEL AND LACK OF GND TRAINING ON DISTINGUISHING BTWN MAINT TAGS; I ASSUMED MAINT HAD THE CIRCUIT BREAKER TAGGED AND WAS PROPERLY DOCUMENTED. AN UNRELATED MEL WITH THE A HYD SYS AND #1 REVERSER DISTR ME FROM BRINGING THE CIRCUIT BREAKER UP TO THE CAPT. I BELIEVE I HAD INADEQUATE TRAINING TO ID THE SAFETY TAG FROM OTHER FLYABLE TAGS. ADDITIONALLY; I NEGATIVE XFER OCCURRED FROM ANOTHER CARRIER WHO COLOR CODES CIRCUIT BREAKER TAGS BASED ON FUNCTION; IE; WHITE IS OK; YELLOW IS CAUTION; RED (AND LARGE) IS REMOVE BEFORE FLT. THE TAG IN QUESTION WAS WHITE. FACTORS INVOLVED INCLUDE THE DISTR BY THE HYD MEL; THE LATE ARR OF THE ACFT AT THE GATE; SIMILAR LOOKING 'TAGS;' AND INCOMPLETE MAINT POST TAXI PROCS. COLOR CODE TAGS. IF MAINT COLORS A NON-FLYABLE BREAKER THAT IS NOT AN MEL (AND DOCUMENTED); IT SHOULD BE A BOLD COLOR IN DANGER COLORS OF RED OR YELLOW. WHITE IS A 'NORMAL' CONDITION COLOR FOR FLT DECK PURPOSES (IE; NG DISPLAYS). INITIAL IOE TRAINING SHOULD POINT OUT THE DIFFERENCE OF TAGS AND THEIR IMPORTANCE DURING PREFLT INSPECTION TRAINING. MAINT PROCS SHOULD HAVE WRITTEN GUIDANCE TO SCAN CIRCUIT BREAKERS PRIOR TO RELEASING TO FLT CREWS.

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.