A B737-800 flight crew noticed an increasing fuel totalizer shortly after takeoff. With their fuel q...

Attributes
ACN	807411
Time
Date	200810
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 1000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 250 flight time type : 9000
ASRS Report	807411
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : landed as precaution other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Right after takeoff; the fuel totalizer began increasing to over 1700 pounds over departure fuel. The center tank was causing the erroneous reading and remained at that higher value for the remainder of the flight. We crosschecked the fuel burned with the flight plan and confirmed the error was indeed still there. Dispatch and maintenance control were advised and had no suggestions as there is no procedure in the book for this condition. I had concerns that I didn't really know my departure fuel assuming the gauge was inaccurate at the gate I could not confirm I had the needed fuel to continue to ZZZ1. I confirmed the total gallons added in ZZZ at over 3000 gallons; so I knew we had enough fuel to safely proceed back to ZZZ. I also had suspicions there could have been water contamination causing the erroneous readings. I elected to return to ZZZ and declare an emergency as a precaution in the event we had any engine abnormalities. We also had to land overweight and chose the longest runway at ZZZ. Approach and landing were uneventful and maintenance towed the aircraft to the maintenance hangar. New procedures needed to xchk actual fuel onboard before and after flts and fueling.

Original NASA ASRS Text

Title: A B737-800 FLT CREW NOTICED AN INCREASING FUEL TOTALIZER SHORTLY AFTER TAKEOFF. WITH THEIR FUEL QUANTITY IN DOUBT; THEY DECLARED AN EMERGENCY AND RETURNED TO LAND AT THEIR DEPARTURE AIRPORT.

Narrative: RIGHT AFTER TKOF; THE FUEL TOTALIZER BEGAN INCREASING TO OVER 1700 LBS OVER DEP FUEL. THE CTR TANK WAS CAUSING THE ERRONEOUS READING AND REMAINED AT THAT HIGHER VALUE FOR THE REMAINDER OF THE FLT. WE XCHKED THE FUEL BURNED WITH THE FLT PLAN AND CONFIRMED THE ERROR WAS INDEED STILL THERE. DISPATCH AND MAINT CTL WERE ADVISED AND HAD NO SUGGESTIONS AS THERE IS NO PROC IN THE BOOK FOR THIS CONDITION. I HAD CONCERNS THAT I DIDN'T REALLY KNOW MY DEP FUEL ASSUMING THE GAUGE WAS INACCURATE AT THE GATE I COULD NOT CONFIRM I HAD THE NEEDED FUEL TO CONTINUE TO ZZZ1. I CONFIRMED THE TOTAL GALLONS ADDED IN ZZZ AT OVER 3000 GALLONS; SO I KNEW WE HAD ENOUGH FUEL TO SAFELY PROCEED BACK TO ZZZ. I ALSO HAD SUSPICIONS THERE COULD HAVE BEEN WATER CONTAMINATION CAUSING THE ERRONEOUS READINGS. I ELECTED TO RETURN TO ZZZ AND DECLARE AN EMER AS A PRECAUTION IN THE EVENT WE HAD ANY ENG ABNORMALITIES. WE ALSO HAD TO LAND OVERWT AND CHOSE THE LONGEST RWY AT ZZZ. APCH AND LNDG WERE UNEVENTFUL AND MAINT TOWED THE ACFT TO THE MAINT HANGAR. NEW PROCS NEEDED TO XCHK ACTUAL FUEL ONBOARD BEFORE AND AFTER FLTS AND FUELING.

Data retrieved from NASA's ASRS site as of May 2009 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.

A B737-800 flight crew noticed an increasing fuel totalizer shortly after takeoff. With their fuel quantity in doubt; they declared an emergency and returned to land at their departure airport.