Narrative:

On the morning of jul/wed/04 I went out to the aircraft to address an MEL for the autobrake system. Finding no problems, and not being able to duplicate the write-up, I decided (just to be sure) that I would do a couple of system tests. Per maintenance manual 32-42-00, I pulled the autoslat #1 and #2 dc breakers. I hung 1 circuit breaker lockout device from the upper breaker which covered the other as well. (One breaker is located directly above the other). I felt this would be sufficient since I would not be turning this over to anyone. From there I proceeded with the tests. The first was done from the cockpit alone, while the other had to be accomplished in the east&east bay, for the most part only coming up to turn some things off. By the time I completed the tests, I noted it was only 1/2 hour till departure, and I had to get in and do my paperwork in order to close out the package. (I later found out that the departure time had been changed and it was not leaving till around XA00). I closed up downstairs and went upstairs to get the rest of my stuff. I can remember going into the cockpit and grabbing the lockout device while I was looking around to make sure I did not leave anything and that everything I had turned on was off. I cannot honestly remember pushing in the breakers. I also remember getting a call on the radio about that time, asking how I was doing, and then someone on the ground yelling a question to me. I can't be sure exactly when, and in what order, they took place. Then I went in and finished my paperwork. Callback conversation with reporter revealed the following information: the reporter stated as the job came close to completion, a lot was happening in and around the airplane, getting it ready to go to the gate. The reporter said he does not remember resetting the autoslat dc circuit breakers but, strangely, remembers removing the circuit breaker locks. The reporter stated the crew discovered the breakers open on taxi out for takeoff and returned to the gate for maintenance information.

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Original NASA ASRS Text

Title: A B737-400, PRIOR TO TKOF, RETURNED TO THE GATE DUE TO AUTOSLAT #1 AND AUTOSLAT #2 DC BREAKERS NOT BEING SET. BREAKERS PULLED FOR MAINT AND NOT RESET.

Narrative: ON THE MORNING OF JUL/WED/04 I WENT OUT TO THE ACFT TO ADDRESS AN MEL FOR THE AUTOBRAKE SYS. FINDING NO PROBS, AND NOT BEING ABLE TO DUPLICATE THE WRITE-UP, I DECIDED (JUST TO BE SURE) THAT I WOULD DO A COUPLE OF SYS TESTS. PER MAINT MANUAL 32-42-00, I PULLED THE AUTOSLAT #1 AND #2 DC BREAKERS. I HUNG 1 CIRCUIT BREAKER LOCKOUT DEVICE FROM THE UPPER BREAKER WHICH COVERED THE OTHER AS WELL. (ONE BREAKER IS LOCATED DIRECTLY ABOVE THE OTHER). I FELT THIS WOULD BE SUFFICIENT SINCE I WOULD NOT BE TURNING THIS OVER TO ANYONE. FROM THERE I PROCEEDED WITH THE TESTS. THE FIRST WAS DONE FROM THE COCKPIT ALONE, WHILE THE OTHER HAD TO BE ACCOMPLISHED IN THE E&E BAY, FOR THE MOST PART ONLY COMING UP TO TURN SOME THINGS OFF. BY THE TIME I COMPLETED THE TESTS, I NOTED IT WAS ONLY 1/2 HR TILL DEP, AND I HAD TO GET IN AND DO MY PAPERWORK IN ORDER TO CLOSE OUT THE PACKAGE. (I LATER FOUND OUT THAT THE DEP TIME HAD BEEN CHANGED AND IT WAS NOT LEAVING TILL AROUND XA00). I CLOSED UP DOWNSTAIRS AND WENT UPSTAIRS TO GET THE REST OF MY STUFF. I CAN REMEMBER GOING INTO THE COCKPIT AND GRABBING THE LOCKOUT DEVICE WHILE I WAS LOOKING AROUND TO MAKE SURE I DID NOT LEAVE ANYTHING AND THAT EVERYTHING I HAD TURNED ON WAS OFF. I CANNOT HONESTLY REMEMBER PUSHING IN THE BREAKERS. I ALSO REMEMBER GETTING A CALL ON THE RADIO ABOUT THAT TIME, ASKING HOW I WAS DOING, AND THEN SOMEONE ON THE GND YELLING A QUESTION TO ME. I CAN'T BE SURE EXACTLY WHEN, AND IN WHAT ORDER, THEY TOOK PLACE. THEN I WENT IN AND FINISHED MY PAPERWORK. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED AS THE JOB CAME CLOSE TO COMPLETION, A LOT WAS HAPPENING IN AND AROUND THE AIRPLANE, GETTING IT READY TO GO TO THE GATE. THE RPTR SAID HE DOES NOT REMEMBER RESETTING THE AUTOSLAT DC CIRCUIT BREAKERS BUT, STRANGELY, REMEMBERS REMOVING THE CIRCUIT BREAKER LOCKS. THE RPTR STATED THE CREW DISCOVERED THE BREAKERS OPEN ON TAXI OUT FOR TKOF AND RETURNED TO THE GATE FOR MAINT INFO.

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.