Gravity fuel feeding A320
Hi guys. Have a question regarding gravity fuel feeding ceiling. FCOM says that if the flight time above FL300 is less than 30 minutes(fuel non-deaerated), then the gravity fuel feeding ceiling is FL300. However, if you are on an easterly track, where FL300 is not an option, what would your gravity ceiling be? Would it be FL290, or do you have to descend all the way down to FL150? Would appreciate an answer. Thanks in advance!