B747-200
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Aircraft Equipment Problem Dissipated; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action; Flight Crew Inflight Shutdown
Aircraft; Procedure
While approaching top of climb FL350 for FL360; Number 2 Engine rolled back (no stall or noise). [This was] followed by Number 3 Engine rolling back (slight rumbling sound). I asked the Flight Engineer if [I] was doing anything to cause this? He replied 'no'. Departing from an airport not frequented by our air carrier; I was thinking about possible fuel contamination and becoming a glider. We immediately performed a Rapid Restart. The attempt was unsuccessful. I called ATC and asked for a descent to FL250. While descending through FL310; we attempted another start; again unsuccessful. As we were passing through FL290 we attempted another start. This start was successful. The engines stabilized; and we elected to continue to [our destination]. [We] contacted ATC for climb back to FL360. The rest of the trip was uneventful. The First Officer was at the controls. No engine parameters were ever exceeded. No oil pressure lights were ever illuminated.The Flight Engineer came to me today and informed me that he thought long and hard; and that he remembered having a little different fuel feed going on at the time of the event; and that he had e-mailed the Chief Pilot about it. (Outboard tanks to all engines) He was trying to even out the tanks. I not sure if this had anything to do with this occurrence; but I thought it is best not to omit anything.
During the final segment of the climb reaching FL360 the Number 2 Engine rolled back. The Number 3 Engine rolled back a couple of minutes after. The Flight Engineer (myself) was cross feeding (non-standard) from the Number 1 and 4 main tanks to all engines in an effort to balance all four packages. I stopped the crossfeed placing all fuel pumps ON and concentrated on the issue at hand. The total gross weight of the airplane was approximately 467;000 LBS. The Captain requested a descent to FL250 and was granted by ATC. The first attempt to recover the engines was conducted at FL350 using the rapid relight procedure. The second attempt was at FL310 While the final attempt was at FL290 and the engines recovered. The engines were stabilized and the Captain and crew agreed to climb back to FL360. The rest of the flight was uneventful.
A B747-200 crew reported that at FL360 the Flight Engineer was feeding engines 1/2 from the fuel tank 1 and engines 3/4 from the tank 4 when engines 2 and 3 shutdown. The engines were restarted descending through FL290.