Fuel Imbalance
No limits on ground. During normal refueling for a turnaround,
the dialed in settings will automatically shut off appropriate tanks.
If there is room, all fuel can be transfered to one wing, for maintenance.
Max imbalance inflight is about 3000lbs before the pilot will correct.
Inherent problem on some A/C due to uneven fuel pump feeds.
I think Boeing is still working with pump manuf. on this.