An ATR42 was dispatched with the right fuel tank quantity indicator deferred as inoperative per the ...

Narrative:

This report involves an MEL on the ATR regarding inoperative fuel gauges. The MEL allows the airplane to be flown for up to 10 days with an inoperative fuel quantity indicator. The alternate system used to determine the actual fuel on board is highly inaccurate. We were given an airplane to take from ewr to bwi and the right fuel tank gauge was MEL'ed. With help from maintenance we checked the dripstick numbers, checked the chart and then determined we had 2100 pounds in the right tank. We landed at bwi having burned 600 pounds from the right tank. At this point, we should have had 1500 pounds left. On the ground at bwi we added 80 gallons (536 pounds). At this point the captain and I checked our dripsticks and we both checked the numbers and the charts twice and the sticks indicated just over 1000 pounds. This was a 1000 pound discrepancy in what the fuel sticks said we had and what we thought we had. So we added another 100 gallons (670 pounds) and 'resticked' the tanks, and now the drip tanks indicted 2100 pounds. Another 400 pound discrepancy. This system is dangerous because you cannot accurately determine the amount of fuel on board. If you have a situation where you cannot take a large amount of fuel because of a high passenger load, and you have 1000 pounds less than what you thought you had, you stand a good chance of running out of fuel. The MEL if allowed to exist at all should be limited to one flight to a station where repairs can be made. Callback conversation with reporter revealed the following information: the reporter stated the problem with the fueling was mainly caused by attempting to fuel using the dripsticks to verify the load and having the wrong stick or sticks installed in the tank. The reporter said the metered fuel from the truck was being used to fuel both tanks and should have been used for only the right until the correct load was metered into the right tank.

Original NASA ASRS Text

Title: AN ATR42 WAS DISPATCHED WITH THE R FUEL TANK QUANTITY INDICATOR DEFERRED AS INOP PER THE MEL AND THE WRONG DRIPSTICK OR DRIPSTICKS LOCATED IN THE TANK.

Narrative: THIS RPT INVOLVES AN MEL ON THE ATR REGARDING INOP FUEL GAUGES. THE MEL ALLOWS THE AIRPLANE TO BE FLOWN FOR UP TO 10 DAYS WITH AN INOP FUEL QUANTITY INDICATOR. THE ALTERNATE SYS USED TO DETERMINE THE ACTUAL FUEL ON BOARD IS HIGHLY INACCURATE. WE WERE GIVEN AN AIRPLANE TO TAKE FROM EWR TO BWI AND THE R FUEL TANK GAUGE WAS MEL'ED. WITH HELP FROM MAINT WE CHKED THE DRIPSTICK NUMBERS, CHKED THE CHART AND THEN DETERMINED WE HAD 2100 LBS IN THE R TANK. WE LANDED AT BWI HAVING BURNED 600 LBS FROM THE R TANK. AT THIS POINT, WE SHOULD HAVE HAD 1500 LBS LEFT. ON THE GND AT BWI WE ADDED 80 GALLONS (536 LBS). AT THIS POINT THE CAPT AND I CHKED OUR DRIPSTICKS AND WE BOTH CHKED THE NUMBERS AND THE CHARTS TWICE AND THE STICKS INDICATED JUST OVER 1000 LBS. THIS WAS A 1000 LB DISCREPANCY IN WHAT THE FUEL STICKS SAID WE HAD AND WHAT WE THOUGHT WE HAD. SO WE ADDED ANOTHER 100 GALLONS (670 LBS) AND 'RESTICKED' THE TANKS, AND NOW THE DRIP TANKS INDICTED 2100 LBS. ANOTHER 400 LB DISCREPANCY. THIS SYS IS DANGEROUS BECAUSE YOU CANNOT ACCURATELY DETERMINE THE AMOUNT OF FUEL ON BOARD. IF YOU HAVE A SIT WHERE YOU CANNOT TAKE A LARGE AMOUNT OF FUEL BECAUSE OF A HIGH PAX LOAD, AND YOU HAVE 1000 LBS LESS THAN WHAT YOU THOUGHT YOU HAD, YOU STAND A GOOD CHANCE OF RUNNING OUT OF FUEL. THE MEL IF ALLOWED TO EXIST AT ALL SHOULD BE LIMITED TO ONE FLT TO A STATION WHERE REPAIRS CAN BE MADE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PROB WITH THE FUELING WAS MAINLY CAUSED BY ATTEMPTING TO FUEL USING THE DRIPSTICKS TO VERIFY THE LOAD AND HAVING THE WRONG STICK OR STICKS INSTALLED IN THE TANK. THE RPTR SAID THE METERED FUEL FROM THE TRUCK WAS BEING USED TO FUEL BOTH TANKS AND SHOULD HAVE BEEN USED FOR ONLY THE R UNTIL THE CORRECT LOAD WAS METERED INTO THE R TANK.

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.

Attributes
ACN	429125
Time
Date	199902
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bwi
State Reference	MD
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	ATR 42
Flight Phase	ground : parked ground : preflight
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 50 flight time total : 2700 flight time type : 1000
ASRS Report	429125
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

An ATR42 was dispatched with the right fuel tank quantity indicator deferred as inoperative per the MEL and the wrong dripstick or dripsticks located in the tank.