Narrative:

During the preflight for aircraft X, the flight crew was resetting the standby 'att' dc yellow cap circuit breaker when the circuit breaker stem broke. We did not have a circuit breaker locally available, and it was decided that we would rob a circuit breaker from the aircraft and 'DF/cf' the inoperative system. It was determined by another controller to rob the #2 ADF dc circuit breaker, as he thought that was the deactivated ADF system on the aircraft, and would have no impact on the operation. When I talked with the mechanic, I didn't question which circuit breaker was used, and carried forward the item to have the #2 ADF circuit breaker replaced at the first available opportunity. It was later discovered that te #2 ADF is the operable ADF, and I should have deferred the #2 ADF per the MEL.

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Original NASA ASRS Text

Title: A B737-500 WAS DISPATCHED IN NON COMPLIANCE WITH #2 ADF SYS INOP DUE TO ROBBING THE CIRCUIT BREAKER FOR ANOTHER SYS.

Narrative: DURING THE PREFLT FOR ACFT X, THE FLT CREW WAS RESETTING THE STANDBY 'ATT' DC YELLOW CAP CIRCUIT BREAKER WHEN THE CIRCUIT BREAKER STEM BROKE. WE DID NOT HAVE A CIRCUIT BREAKER LOCALLY AVAILABLE, AND IT WAS DECIDED THAT WE WOULD ROB A CIRCUIT BREAKER FROM THE ACFT AND 'DF/CF' THE INOP SYS. IT WAS DETERMINED BY ANOTHER CTLR TO ROB THE #2 ADF DC CIRCUIT BREAKER, AS HE THOUGHT THAT WAS THE DEACTIVATED ADF SYS ON THE ACFT, AND WOULD HAVE NO IMPACT ON THE OP. WHEN I TALKED WITH THE MECH, I DIDN'T QUESTION WHICH CIRCUIT BREAKER WAS USED, AND CARRIED FORWARD THE ITEM TO HAVE THE #2 ADF CIRCUIT BREAKER REPLACED AT THE FIRST AVAILABLE OPPORTUNITY. IT WAS LATER DISCOVERED THAT TE #2 ADF IS THE OPERABLE ADF, AND I SHOULD HAVE DEFERRED THE #2 ADF PER THE MEL.

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.