Good day everyone. A technical question: i usually set on fuel pumps either on A320 Neo and Boeing 747-8 Intercontinental. In attempt to burn less fuel what would i do? Turn them off or on? Just minding that all the other fuel buttons are on so that the plane might not have any issue with fuel and fuel balances… The only concern is to try if the fuel burn is more with fuel pump turned on and less with them turned off.
Thanks for your hints.
Don’t know A320 and B747 fuel circuits , but if like ATR42/72 , putting fuel pump switch on is mandatory .
Fuel pump is used only for starting and when HMU fuel pressure is OK is automaticaly cut off.
A jet pump then feeds engine HMU using return flow from hmu.
Switch must be ON to open the “motive flow” valve , crossfeed valve must be open to feed engine if not .