An air carrier flight crew finds that the aircraft had been misfueled during the layover. However, d...

Attributes
ACN	330890
Time
Date	199603
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : jac
State Reference	WY
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 8500 flight time type : 3000
ASRS Report	330890
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We brought aircraft in the night before. On returning to aircraft the next morning we discovered that it appeared to be misfueled (limitations of aircraft stated that you can't have more than 1000 pounds of fuel in center tank unless the main tanks are full). We had showing 5300 pounds in #1, 6000 pounds in #2, and 3800 pounds in the center tank. We talked to the local operations people and they said that they did not call for fuel to be added to the center tank. We then attempted to transfer fuel from center tank into mains, but the center tank boost pumps would not pressurize. So now we believed that the center tank gauge is inoperative (in error) because no fuel is being picked up. So being an a&P mechanic I decided to swap fuel gauges. I also checked the circuit breakers, no help. In switching gauges I discovered that they could not be swapped because they had different part numbers so I installed them back in original places and reset the circuit breakers. We then checked the MEL which said we could go with center tank gauge inoperative providing we used another method to verify fuel quantity. We then agreed that if we added 500 pounds to the center tank and the low pressure lights went out that it would verify the tank was empty and that after fueling we had 500 pounds. So after they added the 500 pounds the low pressure lights went out. So we showed this correction on our weight and balance record and departed normally. En route we turned on center tank boost pumps to burn out the 500 pounds. Not only did it burn 500 pounds, but it continued to burn fuel out of center tank till we arrived at the gate in slc. So now this showed us that the gauge was not in error and we actually had 3800+ pounds fuel in the center tank. Having this 3800+ pounds, the 500 pounds we added gave us an incorrect weight and balance sheet.

Original NASA ASRS Text

Title: AN ACR FLC FINDS THAT THE ACFT HAD BEEN MISFUELED DURING THE LAYOVER. HOWEVER, DURING THEIR ATTEMPT TO TRANSFER THE FUEL THEY CONCLUDE THAT THE GAUGE WAS INCORRECT AND GO. INFLT THEY DISCOVER THAT THE ACFT REALLY HAD BEEN MISFUELED.

Narrative: WE BROUGHT ACFT IN THE NIGHT BEFORE. ON RETURNING TO ACFT THE NEXT MORNING WE DISCOVERED THAT IT APPEARED TO BE MISFUELED (LIMITATIONS OF ACFT STATED THAT YOU CAN'T HAVE MORE THAN 1000 LBS OF FUEL IN CTR TANK UNLESS THE MAIN TANKS ARE FULL). WE HAD SHOWING 5300 LBS IN #1, 6000 LBS IN #2, AND 3800 LBS IN THE CTR TANK. WE TALKED TO THE LCL OPS PEOPLE AND THEY SAID THAT THEY DID NOT CALL FOR FUEL TO BE ADDED TO THE CTR TANK. WE THEN ATTEMPTED TO TRANSFER FUEL FROM CTR TANK INTO MAINS, BUT THE CTR TANK BOOST PUMPS WOULD NOT PRESSURIZE. SO NOW WE BELIEVED THAT THE CTR TANK GAUGE IS INOP (IN ERROR) BECAUSE NO FUEL IS BEING PICKED UP. SO BEING AN A&P MECH I DECIDED TO SWAP FUEL GAUGES. I ALSO CHKED THE CIRCUIT BREAKERS, NO HELP. IN SWITCHING GAUGES I DISCOVERED THAT THEY COULD NOT BE SWAPPED BECAUSE THEY HAD DIFFERENT PART NUMBERS SO I INSTALLED THEM BACK IN ORIGINAL PLACES AND RESET THE CIRCUIT BREAKERS. WE THEN CHKED THE MEL WHICH SAID WE COULD GO WITH CTR TANK GAUGE INOP PROVIDING WE USED ANOTHER METHOD TO VERIFY FUEL QUANTITY. WE THEN AGREED THAT IF WE ADDED 500 LBS TO THE CTR TANK AND THE LOW PRESSURE LIGHTS WENT OUT THAT IT WOULD VERIFY THE TANK WAS EMPTY AND THAT AFTER FUELING WE HAD 500 LBS. SO AFTER THEY ADDED THE 500 LBS THE LOW PRESSURE LIGHTS WENT OUT. SO WE SHOWED THIS CORRECTION ON OUR WT AND BAL RECORD AND DEPARTED NORMALLY. ENRTE WE TURNED ON CTR TANK BOOST PUMPS TO BURN OUT THE 500 LBS. NOT ONLY DID IT BURN 500 LBS, BUT IT CONTINUED TO BURN FUEL OUT OF CTR TANK TILL WE ARRIVED AT THE GATE IN SLC. SO NOW THIS SHOWED US THAT THE GAUGE WAS NOT IN ERROR AND WE ACTUALLY HAD 3800+ LBS FUEL IN THE CTR TANK. HAVING THIS 3800+ LBS, THE 500 LBS WE ADDED GAVE US AN INCORRECT WT AND BAL SHEET.

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.

An air carrier flight crew finds that the aircraft had been misfueled during the layover. However, during their attempt to transfer the fuel they conclude that the gauge was incorrect and go. In-flight they discover that the aircraft really had been misfueled.