What precaution must be observed when a gravity-feed fuel system supplies fuel from multiple tanks?

In a gravity-feed fuel system that utilizes multiple fuel tanks, it is essential for the tank airspaces to be interconnected to maintain consistent pressure and facilitate proper fuel flow. When tanks are interconnected, the airspace above the fuel in each tank can equalize, preventing the creation of a vacuum when fuel is drawn from one or more tanks. This interconnectedness ensures that the gravitational pull effectively moves fuel from each tank as needed, thus ensuring a steady supply.

If the tanks were not interconnected, the pressure in each tank could potentially vary as fuel is consumed, leading to fuel starvation or inconsistent fuel delivery. Additionally, interconnected airspaces prevent the formation of vacuum pockets, which can hinder fuel flow and complicate fuel management. Therefore, maintaining interconnections helps to ensure that the system operates efficiently and safely.