Aircraft equipment problem. Fuel tank indications intermittent and erroneous.

Attributes
ACN	335895
Time
Date	199605
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : orf
State Reference	VA
Altitude	msl bound lower : 37000 msl bound upper : 37000
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	335895
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Location: orf. Over orf at FL370. Fuel tank temperature minus 24. Right outer tank had been reading zero qty, increased to 4000 pounds and trim tank qty increased 1000 pounds. Cgcc faulted. Outer tanks were even at 8800 pounds. 5 mins later left outer tank qty went to xx and trim tank qty showed a dash in hundreds position. Descended to FL350 and left outer qty came back showing same as right outer qty 8500 pounds. Trim tank and left inner still reading incorrectly. Descended to FL190 and left outer qty dropped to 1000 pounds less than right outer. It remained this way all the way to engine shutdown. When level at 3000 ft the trim and left outer qty corrected to show zero qty. This malfunction occurs on approximately 40 percent of the fleet during the winter. The maintenance corrective action is not solving the problem. How would we be able to detect a fuel leak in this situation? How can we tell if we are in balance? If we had another malfunction this problem would be distracting. Other fleets operating in the caribbean do not seem to have this problem. Perhaps we need to change the fuel qty system.

Original NASA ASRS Text

Title: ACFT EQUIP PROB. FUEL TANK INDICATIONS INTERMITTENT AND ERRONEOUS.

Narrative: LOCATION: ORF. OVER ORF AT FL370. FUEL TANK TEMP MINUS 24. RIGHT OUTER TANK HAD BEEN READING ZERO QTY, INCREASED TO 4000 LBS AND TRIM TANK QTY INCREASED 1000 LBS. CGCC FAULTED. OUTER TANKS WERE EVEN AT 8800 LBS. 5 MINS LATER L OUTER TANK QTY WENT TO XX AND TRIM TANK QTY SHOWED A DASH IN HUNDREDS POS. DSNDED TO FL350 AND L OUTER QTY CAME BACK SHOWING SAME AS R OUTER QTY 8500 LBS. TRIM TANK AND L INNER STILL READING INCORRECTLY. DSNDED TO FL190 AND L OUTER QTY DROPPED TO 1000 LBS LESS THAN R OUTER. IT REMAINED THIS WAY ALL THE WAY TO ENG SHUTDOWN. WHEN LEVEL AT 3000 FT THE TRIM AND L OUTER QTY CORRECTED TO SHOW ZERO QTY. THIS MALFUNCTION OCCURS ON APPROX 40 PERCENT OF THE FLEET DURING THE WINTER. THE MAINT CORRECTIVE ACTION IS NOT SOLVING THE PROB. HOW WOULD WE BE ABLE TO DETECT A FUEL LEAK IN THIS SIT? HOW CAN WE TELL IF WE ARE IN BAL? IF WE HAD ANOTHER MALFUNCTION THIS PROB WOULD BE DISTRACTING. OTHER FLEETS OPERATING IN THE CARIBBEAN DO NOT SEEM TO HAVE THIS PROB. PERHAPS WE NEED TO CHANGE THE FUEL QTY SYS.

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.