When using the ctre tank do they on the 777 switch off the pumps with 500kg remaining in the tank as is done on 75/76's due the alleged problems with fuel pumps. On the 76 this amount gets scavenged when the wing tanks are down to approx 7 tons each side. Mmm! just wondering?
you get an EICAS msg when the centre tanks pumps are on, and the qty is around 900kg. You then turn off the centre tank pumps for the remainder of the flight. Later on as the Wing tank qty decreases, two transfer jet pumps transfer this 900kg to the wing tanks. This procedure is completed well before landing.