Hi,
My recollection was that the 707, 737-200 & L1011 had a note in the Limitations Section of the Flying Manual, that the fuel cross feed must be closed for Approach and Landing. I think the classic B747 had the same limitation.
The B747-400, 737-NG and A320 series don't have such a limitation i.e. they may have the fuel cross feed open for approach and landing.
So it depends on which variant you are flying and what the Limitations section of the FCOM says.
It's a mystery to me why it was a restriction in the first place. I can only guess it was originally due to something with VMCA demonstration flight on the GA and flying with up to 5 degs bank into the live engine(s) and fuel transfer from the high wing to the engine(s) on the low through the open cross feed and fuel imbalance could go out of limits.
It looks like the problem has been designed out in modern aircraft.
Last edited by rudderrudderrat; 2nd Apr 2010 at 10:12.
Reason: typo