Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 112; Flight Crew Total 997; Flight Crew Type 92
Confusion; Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance; Inflight Event / Encounter Fuel Issue
Flight Crew Overcame Equipment Problem
Manuals
ECL Non-Normal FUEL IMBALANCE checklist appears to be able to lead a pilot to turn off all main fuel pumps in the low quantity fuel tank with all cross-feed valves closed.We were dispatched and fueled with no center tank fuel and less than full main tanks. About three hours into the flight we got a FUEL IN CENTER advisory EICAS message.We turned on both center tank fuel pumps to the burn the center tank fuel. We noted that the right main tank had approximately 1;600 lbs less fuel than the left main tank. We determined the engines were burning evenly and suspected that fuel had transferred from the right tank to the center tank.We did not have a FUEL IMBALANCE advisory EICAS message but we went to the ECL FUEL IMBALANCE checklist to attempt to balance the fuel. We determined; per the checklist; there was no fuel leak and commenced the checklist.Page 3 of the checklist: there is a box that says'There is no indication of an engine fuel leak and the FUEL IMBALANCE message shows' We checked the NO box as we did not have the FUEL IMBALANCE EICAS message. Upon checking NO; that step blued out showing we completed that step and the very next step; FUEL CROSSFEED switch (either): ON; blued out as well. In other words; upon the FUEL CROSSFEED step bluing out there was no switching to occur per the checklist.Page 4 of the checklist: asks if the Left main tank quantity is low. We checked 'NO' which blued the rest of that page out.Page 5 of the checklist: asks if the Right main tank quantity is low. We checked 'YES'The next step directed and stated 'R fuel PUMPS FWD and AFT switches(both): OFFThis allows fuel from the higher quantity tank to feed both engines. The next and final step of Page 5 is to check when fuel balancing is complete. At no point does the ECL in our configuration direct us to open the crossfeed valves. We did NOT turn off the R main fuel pumps and elected to leave the imbalance as it was as we were not at the fuel imbalance limit. We did contact Maintenance Control and wrote up the fuel transfer issue.Guidance from our training is to follow the ECL without second guessing it. I completely understand the rational as some of the checklists are complicated but in this case had we follow the checklist verbatim we would have had the left tank fuel pumps supplying the left engine and the right engine being fed by no fuel pumps at all. Furthermore; I looked at the 777 Flight Manual Non-Normal FUEL IMBALANCE checklist. It is different from the ECL. Following that checklist would have led to proper fuel balancing.In conclusion: The ECL FUEL IMBALANCE checklist; under certain circumstances; can lead to an engine being fed by no fuel pumps. The 777 Flight Manual illustrates a discrepancy with the ECL. The 777 Flight Manual leads to configuration so the engine will be supplied with fuel pump pressure.
B777 Captain reported a discrepancy between checklists and the flight manual while attempting to correct a fuel imbalance.