Originally Posted by
carnival30
I guess lets just simplify the question.
Can one engine take fuel from both the main tanks with the crossfeed valve closed?
No! That’s what crossfeed valves are designed for.
And one eng. inoperativ cruise speed is 410kts TAS for alternate calculation... so fuel should never be a problem in the event of an eng. failure during cruise and correct flight planning ...
And why don’t you want to open the crossfeed valve?
Checklist states: „balance fuel as needed“