A B777 diverted after a fuel system malfunction transferred fuel into the right main tank while burn...

Attributes
ACN	788096
Time
Date	200805
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 32000
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 23000 flight time type : 2000
ASRS Report	788096
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : eicas other flight crewa
Resolutory Action	flight crew : diverted to another airport flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Aircraft

Narrative:

After 2 hours of flight; fuel imbal on EICAS came on. This maintenance event had occurred on the previous flight also and had been cleared by maintenance. Followed flight manual procedure with help of dispatch and maintenance. We determined fuel was being xferred into the right main tank; while center tank was being used. Operations elected to have us divert to ZZZ for a plane change rather than continue. We dumped 50000 pounds of fuel which was reported to ATC and landed ZZZ with no further action. We had to stop center tank burn and rebalance the fuel 3 times during this 4 hour period.

Original NASA ASRS Text

Title: A B777 DIVERTED AFTER A FUEL SYSTEM MALFUNCTION TRANSFERRED FUEL INTO THE R MAIN TANK WHILE BURNING CENTER TANK FUEL.

Narrative: AFTER 2 HRS OF FLT; FUEL IMBAL ON EICAS CAME ON. THIS MAINT EVENT HAD OCCURRED ON THE PREVIOUS FLT ALSO AND HAD BEEN CLRED BY MAINT. FOLLOWED FLT MANUAL PROC WITH HELP OF DISPATCH AND MAINT. WE DETERMINED FUEL WAS BEING XFERRED INTO THE R MAIN TANK; WHILE CTR TANK WAS BEING USED. OPS ELECTED TO HAVE US DIVERT TO ZZZ FOR A PLANE CHANGE RATHER THAN CONTINUE. WE DUMPED 50000 LBS OF FUEL WHICH WAS RPTED TO ATC AND LANDED ZZZ WITH NO FURTHER ACTION. WE HAD TO STOP CTR TANK BURN AND REBALANCE THE FUEL 3 TIMES DURING THIS 4 HR PERIOD.

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 B777 diverted after a fuel system malfunction transferred fuel into the right main tank while burning center tank fuel.