B747-C/F
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue
Flight Crew Inflight Shutdown; General Maintenance Action
Aircraft
When climbing out and passing around FL180 we notice the number 3 engine roll back momentarily; followed by an ENGINE 3 THRUST. We ran the QRH with no action required. We then received an engine 3 fuel filter message. The QRH was run; both messages cleared by themselves. Engine 3 fuel filter message reappeared momentarily a couple more times. Dispatch and MX was contacted through a phone patch to inform them. The flight continued on with no engine problems. Around 2hrs later we requested a performance climb from FL310 to FL330. During the climb we noticed engine 3 N1 was lagging behind; followed by engine 3 thrust message. We leveled off at FL330 and the number 3 engine was unstable on all parameters. We requested a descent back to FL310. Once level the engine remained unstable; lagging behind around 5% and the N1 bounced around +-2% fuel flow from 1.0 to 3.0. Mx and dispatch were consulted again. We disconnected the auto throttles and slowly retarded engine 3 until it was stable 79%. We continued on in that configuration. As the flight continued we noticed that the thrust was slowly reducing from what was being commanded. I was then relieved for crew rest. I was told that during crew rest the engine slowly continued to roll back until ENGINE 3 FAIL message was displayed and the engine was shut down per the QRH. The flight continued to destination with no further issues.We had previously operated this plane around 14 hrs earlier and the plane had not flown since. We were concerned that we had uplifted bad fuel in ZSPD. We knew that main tanks 1 & 4 fuel was from [the previous flight origin] and the fuel we up lifted in ZSPD was in main 2&3. We took precaution through fuel management to keep engines 1&4 from using the possibly contaminated fuel from the main 2&3 and kept close eye on engine 2 for any possible signs of problems and continuously had alternate airports in mind if engine 2 showed signs of problems.
B747 First Officer noted the number 3 engine rolled back momentarily while climbing through FL180; followed by an ENGINE 3 THRUST EICAS and intermittent fuel filter messages. Several hours into the flight; the number three engine thrust began to degrade and thrust was reduced until stable operation was achieved. Eventually the engine could not maintain stable operation at idle and was shut down. Flight continued to the destination. Contaminated fuel was thought to be the issue.