Cross Check - I should have been more 'precise' with my post
(Trying the 'KISS' principle!) It was indeed tank 'feed' position I meant (- 1-500's).
This, from Chris Brady's site (HOPEFULLY with his permission!
) is what I was referring to
"NB On the classics, when departing with less than 1,000kg of fuel in the centre tank, an imbalance may occur during the climb. This is because the RH centre tank pump will stop feeding due to the body angle so number 2 engine fuel is drawn from main tank 2, while engine 1 is still drawing fuel from the centre tank. When this “runs dry” the scavenge pump will also transfer any remaining centre tank fuel into main tank 1, thereby exacerbating the imbalance."
'Scuse me if you were 'TIC' about the aux tank, (and it is a WHILE since I operated one) but I understand use of ctre before aux can give c of g problems (as can refuelling the aux before the ctre is full!) hence the tank output differential. I concur with the tank output v check valve analysis you post and "the location of the 2 centre tank pumps and their different flow rates" referred to the flow rates due to pitch angle.
Must try harder
