B737 Which Fuel Pumps to turn on when starting APU?
Hello everyone,
I am currently undergoing ground training for B737NG and have come up with question regarding APU ops.
FCOM really does not specify which fuel pump is to be turned on when starting APU,
The company procedure states that, "If fuel is loaded in the center tank more than 1,000 lbs, position the CTR FUEL PUMPS L switch ON to prevent a fuel imbalance before takeoff. Otherwise turn on AFT FUEL PUMPS 1 or FWD FUEL PUMPS 2."
I am sure everyone has many different views and understandings on fuel pump operations I am having hard time why those pumps are chose ones? to be turned on.
My understanding is that, turning on AFT fuel pump1 will feed fuel through linings all the way to the APU however it is consuming fuel from left tank which means that fuel will be imbalanced before takeoff. Absolutely no idea why company states "or FWD FUEL PUMP2.