Cac,
Thanks for the reply and the insight about the in-transit lights. But I still have trouble buying it. Because at the point in the flight where we leave a crossfeed open, all tanks have EQUAL fuel. So if a crossfeed valve fails in the open or closed position, who cares?
I have always been a fan of never closing #1 & #4 crossfeeds just to give me options in case of xfeed valve failure.
But still can't see the logic in leaving just one (preferably 1 or 4) that many operators use.