It could also potentially become  an issue if there's a problem with the aircraft's fuel pump system. As the  fuel source is located below the engines, the tail-mounted engines cannot  make use of gravity to self-feed.

如果飞机的燃油泵系统出现问题，也可能成为问题。由于燃料源位于发动机下方，尾部安装的发动机无法利用重力自行供油。