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A B757-200 in cruise at FL370 captain observes 2 circuit breakers with caps missing on P6-3 panel. Breakers located behind first officer's seat just above floor level.
| Attributes | |
| ACN | 598940 |
| Time | |
| Date | 200311 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | msl single value : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zzz.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 194 flight time total : 11100 flight time type : 3100 |
| ASRS Report | 598940 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | aircraft equipment problem : less severe other anomaly other |
| Independent Detector | other flight crewa other flight crewb |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other other |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
Narrative:
After leveling at our cruise altitude, while still seated in the left seat, I was looking around the flight deck when I noticed something odd about one of the circuit breakers on the lower panel. On closer inspection I realized that the head of the circuit breaker was missing, as was the one next to it (panel P6-3 circuit breakers C14 and C17). All system were operating normally and continued to for the rest of the flight. I missed seeing them on my preflight because I am used to looking for the white of a tripped circuit breaker. I have never seen a decapitated circuit breaker before. I think the angle and lighting during my preflight probably contributed to my missing the difference in them during my cockpit set up. We advised maintenance control via ACARS immediately and did logbook, etc. Callback conversation with reporter revealed the following information: the reporter stated the circuit breakers were not missing but were decapitated. The reporter said the circuit breakers were in and functional but could not be pulled.
Original NASA ASRS Text
Title: A B757-200 IN CRUISE AT FL370 CAPT OBSERVES 2 CIRCUIT BREAKERS WITH CAPS MISSING ON P6-3 PANEL. BREAKERS LOCATED BEHIND FO'S SEAT JUST ABOVE FLOOR LEVEL.
Narrative: AFTER LEVELING AT OUR CRUISE ALT, WHILE STILL SEATED IN THE L SEAT, I WAS LOOKING AROUND THE FLT DECK WHEN I NOTICED SOMETHING ODD ABOUT ONE OF THE CIRCUIT BREAKERS ON THE LOWER PANEL. ON CLOSER INSPECTION I REALIZED THAT THE HEAD OF THE CIRCUIT BREAKER WAS MISSING, AS WAS THE ONE NEXT TO IT (PANEL P6-3 CIRCUIT BREAKERS C14 AND C17). ALL SYS WERE OPERATING NORMALLY AND CONTINUED TO FOR THE REST OF THE FLT. I MISSED SEEING THEM ON MY PREFLT BECAUSE I AM USED TO LOOKING FOR THE WHITE OF A TRIPPED CIRCUIT BREAKER. I HAVE NEVER SEEN A DECAPITATED CIRCUIT BREAKER BEFORE. I THINK THE ANGLE AND LIGHTING DURING MY PREFLT PROBABLY CONTRIBUTED TO MY MISSING THE DIFFERENCE IN THEM DURING MY COCKPIT SET UP. WE ADVISED MAINT CTL VIA ACARS IMMEDIATELY AND DID LOGBOOK, ETC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CIRCUIT BREAKERS WERE NOT MISSING BUT WERE DECAPITATED. THE RPTR SAID THE CIRCUIT BREAKERS WERE IN AND FUNCTIONAL BUT COULD NOT BE PULLED.
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.