A B757 flight crew have a fuel imbal which leads them to believe that they may have a fuel leak or blockage. They decide to divert to have the aircraft looked at by maintenance.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	596239
Time
Date	200310
Day	Fri
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl bound lower : 18000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zla.artcc tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	596239
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	596232
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : fuel gages other flight crewa
Resolutory Action	flight crew : landed as precaution flight crew : diverted to alternate
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Noticed approximately 1000 pounds fuel imbal passing FL180. Decided to wait until leveloff to address issue. Upon level at FL370, noticed right tank 3000 pounds heavier than left. Checked fuel used, total fuel indications on FMC. As best we could tell, our leveloff fuel indicated approximately 3000 pounds less than planned. Captain referred to irregular procedure for fuel confign light illuminated. Decided against attempting to balance fuel due to uncertainty of cause of imbal (ie, possible fuel leak in left tank). Fuel in right tank appeared to be stuck at '12.8.' verified right wing heavy by hand flying aircraft and using rudder trim to level wings. Trim required increased from 2.0 units to 4.0 units as flight progressed due to increasing imbal. Unable to determine if fuel in right wing was trapped and unusable. Decided to divert into lax since it was only 60 mi behind us and WX was clear rather than continue to den. Dispatch and maintenance concurred with divert decision since fuel state could not be verified. Requested and received priority handling into lax for uneventful landing.

Original NASA ASRS Text

Title: A B757 FLT CREW HAVE A FUEL IMBAL WHICH LEADS THEM TO BELIEVE THAT THEY MAY HAVE A FUEL LEAK OR BLOCKAGE. THEY DECIDE TO DIVERT TO HAVE THE ACFT LOOKED AT BY MAINT.

Narrative: NOTICED APPROX 1000 LBS FUEL IMBAL PASSING FL180. DECIDED TO WAIT UNTIL LEVELOFF TO ADDRESS ISSUE. UPON LEVEL AT FL370, NOTICED R TANK 3000 LBS HEAVIER THAN L. CHKED FUEL USED, TOTAL FUEL INDICATIONS ON FMC. AS BEST WE COULD TELL, OUR LEVELOFF FUEL INDICATED APPROX 3000 LBS LESS THAN PLANNED. CAPT REFERRED TO IRREGULAR PROC FOR FUEL CONFIGN LIGHT ILLUMINATED. DECIDED AGAINST ATTEMPTING TO BAL FUEL DUE TO UNCERTAINTY OF CAUSE OF IMBAL (IE, POSSIBLE FUEL LEAK IN L TANK). FUEL IN R TANK APPEARED TO BE STUCK AT '12.8.' VERIFIED R WING HVY BY HAND FLYING ACFT AND USING RUDDER TRIM TO LEVEL WINGS. TRIM REQUIRED INCREASED FROM 2.0 UNITS TO 4.0 UNITS AS FLT PROGRESSED DUE TO INCREASING IMBAL. UNABLE TO DETERMINE IF FUEL IN R WING WAS TRAPPED AND UNUSABLE. DECIDED TO DIVERT INTO LAX SINCE IT WAS ONLY 60 MI BEHIND US AND WX WAS CLR RATHER THAN CONTINUE TO DEN. DISPATCH AND MAINT CONCURRED WITH DIVERT DECISION SINCE FUEL STATE COULD NOT BE VERIFIED. REQUESTED AND RECEIVED PRIORITY HANDLING INTO LAX FOR UNEVENTFUL LNDG.

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.