Narrative:

On preflight in slc, the fuel xfeed switch was latched out of position to 'open' and was not noticed by either crew member. Although an EICAS feature known as 'fuel confign' light would have normally alerted us to the gradual fuel imbal occurring on the overhead fuel panel, the 'fuel confign' light now comes on all of the time due to a temporary procedure of carrying fuel in the center tank with center tank fuel pumps off. As a result, the fuel imbal was not noticed until just prior to descent into dfw, resulting in a fuel imbal of 7500 pounds arriving at the gate. Although a fuel limitation of 1500 pounds does exist for dispatch, there appears to be none once dispatched other than monitor the 'fuel confign' light. There never was a safety of flight such as running out of fuel or having an engine quit. There was, however, no excuse for missing the switch being out of position for almost 1 1/2 hours. I feel that with the current procedures involving the 'fuel confign' light that this will occur again. I will, from now on, pay much more attention to the actual fuel tank readings on the overhead panel and less to the total quantity and the 'fuel confign' light which is a caution light become useless. Supplemental information from acn 405515: notes: 1) this particular B767-300 flew hands off with no additional lateral trim with 7500 pounds fuel imbal between left and right tanks. 2) although there is a limitation of 1500 pounds fuel imbal for takeoff, there is none for in-flight except for 'monitor fuel confign light' -- the same light that is now on all the time. Callback conversation with reporter acn #405515 revealed the following information: the captain stated that this new procedure is used to prevent any fuel vapor ignition with fuel loads less than 1000 pounds of fuel in the center tank. The fuel system in the B767 is similar to that of the B747. The company, the FAA and the manufacturer got together and came up with this approach to a possible fuel tank ignition problem. The center tank carries at least 1000 pounds and the pumps are kept off. This is for short duration flts of about 2 1/2 hours and less. The captain said that the fuel gauges are a liquid crystal type and mounted overhead so that they are very difficult to see. Thus the 'fuel confign' warning lights to alert the crew of a problem. There is no 'second warning' unless there was a reset of the system. The fuel at arrival was 2700 pounds in the left tank and 9700 pounds in the right tank. He felt that this was an abnormal imbal, although with the xfeed open you are bound to get a certain amount due to the pressure differential of the pumps. He feels that this new procedure was hastily contrived and allows murphy's law to arise somewhere. He admitted to missing the xfeed valve position, it is normally in the closed position, except this one time upon the aircraft's arrival for their flight.

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Original NASA ASRS Text

Title: A B767-300 FLC FAILS TO ENSURE THAT THE XFEED VALVE IS POSITIONED CLOSED IN ACCORDANCE WITH THEIR BEFORE STARTING ENGS CHKLIST. ACFT SUFFERS A FUEL IMBAL OF 7500 LBS AFTER A 1 PT 5 HR FLT. ACFT LANDS WITH THAT IMBAL CONDITION. THEIR EICAS SYS COULD NOT ALERT THE CREW SINCE THE CTR TANK PUMPS WERE CARRIED IN THE OFF POS, FOLLOWING A NEW COMPANY PROC, THEREBY LIGHTING THE 'FUEL CONFIGN' LIGHT CONSTANTLY.

Narrative: ON PREFLT IN SLC, THE FUEL XFEED SWITCH WAS LATCHED OUT OF POS TO 'OPEN' AND WAS NOT NOTICED BY EITHER CREW MEMBER. ALTHOUGH AN EICAS FEATURE KNOWN AS 'FUEL CONFIGN' LIGHT WOULD HAVE NORMALLY ALERTED US TO THE GRADUAL FUEL IMBAL OCCURRING ON THE OVERHEAD FUEL PANEL, THE 'FUEL CONFIGN' LIGHT NOW COMES ON ALL OF THE TIME DUE TO A TEMPORARY PROC OF CARRYING FUEL IN THE CTR TANK WITH CTR TANK FUEL PUMPS OFF. AS A RESULT, THE FUEL IMBAL WAS NOT NOTICED UNTIL JUST PRIOR TO DSCNT INTO DFW, RESULTING IN A FUEL IMBAL OF 7500 LBS ARRIVING AT THE GATE. ALTHOUGH A FUEL LIMITATION OF 1500 LBS DOES EXIST FOR DISPATCH, THERE APPEARS TO BE NONE ONCE DISPATCHED OTHER THAN MONITOR THE 'FUEL CONFIGN' LIGHT. THERE NEVER WAS A SAFETY OF FLT SUCH AS RUNNING OUT OF FUEL OR HAVING AN ENG QUIT. THERE WAS, HOWEVER, NO EXCUSE FOR MISSING THE SWITCH BEING OUT OF POS FOR ALMOST 1 1/2 HRS. I FEEL THAT WITH THE CURRENT PROCS INVOLVING THE 'FUEL CONFIGN' LIGHT THAT THIS WILL OCCUR AGAIN. I WILL, FROM NOW ON, PAY MUCH MORE ATTN TO THE ACTUAL FUEL TANK READINGS ON THE OVERHEAD PANEL AND LESS TO THE TOTAL QUANTITY AND THE 'FUEL CONFIGN' LIGHT WHICH IS A CAUTION LIGHT BECOME USELESS. SUPPLEMENTAL INFO FROM ACN 405515: NOTES: 1) THIS PARTICULAR B767-300 FLEW HANDS OFF WITH NO ADDITIONAL LATERAL TRIM WITH 7500 LBS FUEL IMBAL BTWN L AND R TANKS. 2) ALTHOUGH THERE IS A LIMITATION OF 1500 LBS FUEL IMBAL FOR TKOF, THERE IS NONE FOR INFLT EXCEPT FOR 'MONITOR FUEL CONFIGN LIGHT' -- THE SAME LIGHT THAT IS NOW ON ALL THE TIME. CALLBACK CONVERSATION WITH RPTR ACN #405515 REVEALED THE FOLLOWING INFO: THE CAPT STATED THAT THIS NEW PROC IS USED TO PREVENT ANY FUEL VAPOR IGNITION WITH FUEL LOADS LESS THAN 1000 LBS OF FUEL IN THE CTR TANK. THE FUEL SYS IN THE B767 IS SIMILAR TO THAT OF THE B747. THE COMPANY, THE FAA AND THE MANUFACTURER GOT TOGETHER AND CAME UP WITH THIS APCH TO A POSSIBLE FUEL TANK IGNITION PROB. THE CTR TANK CARRIES AT LEAST 1000 LBS AND THE PUMPS ARE KEPT OFF. THIS IS FOR SHORT DURATION FLTS OF ABOUT 2 1/2 HRS AND LESS. THE CAPT SAID THAT THE FUEL GAUGES ARE A LIQUID CRYSTAL TYPE AND MOUNTED OVERHEAD SO THAT THEY ARE VERY DIFFICULT TO SEE. THUS THE 'FUEL CONFIGN' WARNING LIGHTS TO ALERT THE CREW OF A PROB. THERE IS NO 'SECOND WARNING' UNLESS THERE WAS A RESET OF THE SYS. THE FUEL AT ARR WAS 2700 LBS IN THE L TANK AND 9700 LBS IN THE R TANK. HE FELT THAT THIS WAS AN ABNORMAL IMBAL, ALTHOUGH WITH THE XFEED OPEN YOU ARE BOUND TO GET A CERTAIN AMOUNT DUE TO THE PRESSURE DIFFERENTIAL OF THE PUMPS. HE FEELS THAT THIS NEW PROC WAS HASTILY CONTRIVED AND ALLOWS MURPHY'S LAW TO ARISE SOMEWHERE. HE ADMITTED TO MISSING THE XFEED VALVE POS, IT IS NORMALLY IN THE CLOSED POS, EXCEPT THIS ONE TIME UPON THE ACFT'S ARR FOR THEIR FLT.

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.