Hi chksix,
Our B737-700 aircraft have the four cell auxiliary system, one in the front and three in the aft cargo compartment.
Thats 1665kg/4794kg capacity.
After t/o, when the center tank gets down to 10,886kg (24,000lbs), but no sooner than 10 minutes after t/o, the transfer of fuel from both aux cells starts automatically, if selected to AUTO.
When the center tank is again full, transfer stops until that 24K level is reached again and the whole thing repeats over.
The rate at which this occurs is dependent on the rate of fuel useage. Remember, both engines are being fed fuel from the center tank.
I understand that about 40 minutes is required to refill the center tank in cruise flight, thats the combination of fuel useage from the center tank, and the fuel being transferred into the same tank.
Cheers, FD
