B747-400
Flight Crew Air Transport Pilot (ATP)
Troubleshooting; Confusion; Human-Machine Interface; Time Pressure
Aircraft Equipment Problem Critical
General Declared Emergency
Aircraft; Environment - Non Weather Related; Human Factors
Upon arrival at the aircraft for the trip; we were informed that the number one fuel indication was inoperative; and an MEL was issued and complied with by manually entering the fuel on the performance page. Fuel calculations were carried out in accordance with standard company procedures in flight. Approximately 30 minutes into the flight; the number one fuel indication repopulated; as did the totalizer; but we continued to operate per the MEL.Approximately 1 hour and 20 minutes into the flight we received a 'FUEL PRESS ENG 1' EICAS message approximately 10 minutes after selecting tank to engine fuel configuration. Upon viewing the fuel secondary EICAS page; we noted that both main fuel pumps in tank 1 indicated amber. Simultaneously; engine 1 rolled back to 30% N1; with no secondary indications. The QRH procedure was run in its entirety and; upon selecting override pump 2; engine 1 returned to normal N1. We called Operations to explain the situation and look for a suitable landing site; which we determined would have to be our destination due to insufficient fuel to turn back and Dispatch's direction not to divert. We declared minimum fuel for the rest of the flight and utilized an auto land at our destination without further incident. Upon blocking in; the quantity indicators for tanks 1 to 4 read: 0.0; 7.1; 11.6 and 4.0 respectively. Approximately 10 minutes after block in; the number 1 tank changed to 14.7; with no changes made to the fueling quantity or system.
[Narrative #2 contained no additional information.]
The flight crew of a B747-400; dispatched with an inoperative #1 fuel quantity indicator inoperative; suffered additional fuel system anomalies with the number one system including a temporary rollback of engine on N1 when they switched to 'main tank to engine' configuration.