Narrative:

Aircraft has had a chronic problem of all the fuel quantity indications blanking in-flight. The aircraft had been held OTS on numerous occasions, and even included boeing working on the aircraft in YYY on mar/xb/01 for several days! On mar/xa/01 I answered a commercial radio call concerning aircraft on flight from ZZZ to XXX. The flight crew indicated that all 3 fuel quantity indications were fluctuating, a new scenario for this chronic fuel quantity indicating system. The crew was concerned that they were unable to rely on the fuel quantity system, but felt comfortable with the fuel used was correct for their flight regime. I offered to the crew, the 2 circuit breakers for the fuel quantity indication system to see if they could get the fluctuation to stop. I asked them if they wanted to pull the #1 fuel quantity processor breaker, on the pll panel C34 after the crew pulled the quantity indicate on continued to fluctuate. I then had the crew reset the #1 processor circuit breaker, and confirm they still had fuel quantity indications. After they confirmed the indications were still present, they pulled the #2 fuel quantity processor circuit breaker on the P11 panel, M19. The crew reported that the fluctuations had stopped, and that their fuel quantity indications appeared normal. The flight crew reset the #2 fuel quantity processor circuit breaker later in-flight, and the fuel quantity indication continued to function normally with no fluctuations noted. I entered a log item into the computer stating the condition the aircraft had, and what actions had been done till that point. The aircraft again was taken OTS and underwent extensive troubleshooting for another 6+ days, which included a verification flight to confirm the said system was operating correctly. The issue of this report is the question 'do we have the approval to cycle circuit breakers in-flight?' the FAA is asking questions of what manual or policy do we have that allows us to do that in-flight. The only manual is the B767 flight manual, procedural index section, pages a and B, which contains the information of cycling of circuit breakers, and that decision is based solely at the captain's discretion. There are discussions ongoing within air carrier X now as to whether a policy needs to be adopted to allow us to cycle circuit breakers when an aircraft is either off the blocks, or in-flight to correct a maintenance problem. Callback conversation with reporter revealed the following information: the reporter stated the FAA investigated this incident. The resolution seems to be rewriting the operations manual. The reporter said the manual will use the ground limits and adapt them to the flight mode. The reporter stated the manual will read 'cycling a circuit breaker in the air should be only accomplished per flight manual normal, additional irregular, or emergency procedure, or in the judgement of the captain and dispatch/maintenance controller has determined that it is safe to do so.'

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Original NASA ASRS Text

Title: A B767-200 INFLT WITH #1 AND #2 FUEL QUANTITY INDICATORS FLUCTUATING WAS REQUESTED BY MAINT CTL TO CYCLE #1 AND #2 FUEL QUANTITY CIRCUIT BREAKERS ISOLATING THE FAULTY SYS TO #2 SYS.

Narrative: ACFT HAS HAD A CHRONIC PROB OF ALL THE FUEL QUANTITY INDICATIONS BLANKING INFLT. THE ACFT HAD BEEN HELD OTS ON NUMEROUS OCCASIONS, AND EVEN INCLUDED BOEING WORKING ON THE ACFT IN YYY ON MAR/XB/01 FOR SEVERAL DAYS! ON MAR/XA/01 I ANSWERED A COMMERCIAL RADIO CALL CONCERNING ACFT ON FLT FROM ZZZ TO XXX. THE FLC INDICATED THAT ALL 3 FUEL QUANTITY INDICATIONS WERE FLUCTUATING, A NEW SCENARIO FOR THIS CHRONIC FUEL QUANTITY INDICATING SYS. THE CREW WAS CONCERNED THAT THEY WERE UNABLE TO RELY ON THE FUEL QUANTITY SYS, BUT FELT COMFORTABLE WITH THE FUEL USED WAS CORRECT FOR THEIR FLT REGIME. I OFFERED TO THE CREW, THE 2 CIRCUIT BREAKERS FOR THE FUEL QUANTITY INDICATION SYS TO SEE IF THEY COULD GET THE FLUCTUATION TO STOP. I ASKED THEM IF THEY WANTED TO PULL THE #1 FUEL QUANTITY PROCESSOR BREAKER, ON THE PLL PANEL C34 AFTER THE CREW PULLED THE QUANTITY INDICATE ON CONTINUED TO FLUCTUATE. I THEN HAD THE CREW RESET THE #1 PROCESSOR CIRCUIT BREAKER, AND CONFIRM THEY STILL HAD FUEL QUANTITY INDICATIONS. AFTER THEY CONFIRMED THE INDICATIONS WERE STILL PRESENT, THEY PULLED THE #2 FUEL QUANTITY PROCESSOR CIRCUIT BREAKER ON THE P11 PANEL, M19. THE CREW RPTED THAT THE FLUCTUATIONS HAD STOPPED, AND THAT THEIR FUEL QUANTITY INDICATIONS APPEARED NORMAL. THE FLC RESET THE #2 FUEL QUANTITY PROCESSOR CIRCUIT BREAKER LATER INFLT, AND THE FUEL QUANTITY INDICATION CONTINUED TO FUNCTION NORMALLY WITH NO FLUCTUATIONS NOTED. I ENTERED A LOG ITEM INTO THE COMPUTER STATING THE CONDITION THE ACFT HAD, AND WHAT ACTIONS HAD BEEN DONE TILL THAT POINT. THE ACFT AGAIN WAS TAKEN OTS AND UNDERWENT EXTENSIVE TROUBLESHOOTING FOR ANOTHER 6+ DAYS, WHICH INCLUDED A VERIFICATION FLT TO CONFIRM THE SAID SYS WAS OPERATING CORRECTLY. THE ISSUE OF THIS RPT IS THE QUESTION 'DO WE HAVE THE APPROVAL TO CYCLE CIRCUIT BREAKERS INFLT?' THE FAA IS ASKING QUESTIONS OF WHAT MANUAL OR POLICY DO WE HAVE THAT ALLOWS US TO DO THAT INFLT. THE ONLY MANUAL IS THE B767 FLT MANUAL, PROCEDURAL INDEX SECTION, PAGES A AND B, WHICH CONTAINS THE INFO OF CYCLING OF CIRCUIT BREAKERS, AND THAT DECISION IS BASED SOLELY AT THE CAPT'S DISCRETION. THERE ARE DISCUSSIONS ONGOING WITHIN ACR X NOW AS TO WHETHER A POLICY NEEDS TO BE ADOPTED TO ALLOW US TO CYCLE CIRCUIT BREAKERS WHEN AN ACFT IS EITHER OFF THE BLOCKS, OR INFLT TO CORRECT A MAINT PROB. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FAA INVESTIGATED THIS INCIDENT. THE RESOLUTION SEEMS TO BE REWRITING THE OPS MANUAL. THE RPTR SAID THE MANUAL WILL USE THE GND LIMITS AND ADAPT THEM TO THE FLT MODE. THE RPTR STATED THE MANUAL WILL READ 'CYCLING A CIRCUIT BREAKER IN THE AIR SHOULD BE ONLY ACCOMPLISHED PER FLT MANUAL NORMAL, ADDITIONAL IRREGULAR, OR EMER PROC, OR IN THE JUDGEMENT OF THE CAPT AND DISPATCH/MAINT CTLR HAS DETERMINED THAT IT IS SAFE TO DO SO.'

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.