Originally Posted by
Fursty Ferret
The scenario in question here describes an approach that's just past the IAF. Not the ideal time to be messing with fuel systems other than a quick risk assessment and confirmation of the fuel cross-feed.
I don't understand your "live engine pump" statement. Low pressure fuel is supplied to the spar, whether it's via the cross-feed or the live side tank. The pressure is boosted by the HP pump and unused fuel is returned to that tank, where it is once again available. Doesn't matter where it is - it's a closed loop and provided the pumps are on, fuel will be supplied to the engine. Some of it may indeed flow back through the pumps in the live side, but who cares? It's fuel.
I just wouldn't want the hassle. You can gravity feed via the cross-feed if you really have to.
I meant live engine side fuel pumps. Gravity feed with OEI is not simple it requires bank towards live engine which on approch will complicate the matter. There's no issue with switching off live side fuel pumps. Even if you don't it should be fine as long as fuel pumps on the dead side are working.