Wrong circuit breaker collared by maintenance.

Attributes
ACN	307288
Time
Date	199506
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : clt
State Reference	NC
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 2000
ASRS Report	307288
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : cfi pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 6500 flight time type : 1200
ASRS Report	307276
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On preflight, found that previous maintenance action required for MEL of thrust reverser had pulled and collared wrong circuit breaker, had pulled circuit breaker below label instead of above label. I have found on many occasions that labeling of F-100 circuit breaker panels and many other aircraft can be very confusing. Supplemental information from acn 307276: while complying with a special procedure required by an item being placed on the MEL status, mechanic pulled and collared the incorrect circuit breaker. Obviously there are 2 contributing factors to this error: inattentiveness by the mechanic (time pressure?) and confusing labeling of circuit breakers. The error was made because it was not readily apparent if the circuit breaker label is located above or below the circuit breaker. Consequently, the circuit breaker below the selected label was pulled and collared, when actually the correct breaker was above the label. While the preflight check did detect this error, a less thorough preflight would have allowed it to go into service. 'Check, double-check, then check it again.'

Original NASA ASRS Text

Title: WRONG CIRCUIT BREAKER COLLARED BY MAINT.

Narrative: ON PREFLT, FOUND THAT PREVIOUS MAINT ACTION REQUIRED FOR MEL OF THRUST REVERSER HAD PULLED AND COLLARED WRONG CIRCUIT BREAKER, HAD PULLED CIRCUIT BREAKER BELOW LABEL INSTEAD OF ABOVE LABEL. I HAVE FOUND ON MANY OCCASIONS THAT LABELING OF F-100 CIRCUIT BREAKER PANELS AND MANY OTHER ACFT CAN BE VERY CONFUSING. SUPPLEMENTAL INFO FROM ACN 307276: WHILE COMPLYING WITH A SPECIAL PROC REQUIRED BY AN ITEM BEING PLACED ON THE MEL STATUS, MECH PULLED AND COLLARED THE INCORRECT CIRCUIT BREAKER. OBVIOUSLY THERE ARE 2 CONTRIBUTING FACTORS TO THIS ERROR: INATTENTIVENESS BY THE MECH (TIME PRESSURE?) AND CONFUSING LABELING OF CIRCUIT BREAKERS. THE ERROR WAS MADE BECAUSE IT WAS NOT READILY APPARENT IF THE CIRCUIT BREAKER LABEL IS LOCATED ABOVE OR BELOW THE CIRCUIT BREAKER. CONSEQUENTLY, THE CIRCUIT BREAKER BELOW THE SELECTED LABEL WAS PULLED AND COLLARED, WHEN ACTUALLY THE CORRECT BREAKER WAS ABOVE THE LABEL. WHILE THE PREFLT CHK DID DETECT THIS ERROR, A LESS THOROUGH PREFLT WOULD HAVE ALLOWED IT TO GO INTO SVC. 'CHK, DOUBLE-CHK, THEN CHK IT AGAIN.'

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.