What allows fuel to move from aft to forward in the system?

• A. Flapper valves
• B. Ejector units
• C. Baffles
• D. Fuel pumps

Answer: (B)

The correct choice identifies ejector units as the mechanism that allows fuel to move from the aft (rear) to the forward part of the fuel system. Ejector units, also known as jet pumps, utilize the Venturi effect to create a pressure differential. This differential facilitates the movement of fuel from one area of the tank to another without the need for mechanical pumps. As the ejector unit expels fuel, it generates a low-pressure area that helps draw in additional fuel from the aft section, ensuring a consistent supply that can aid in maintaining balance and proper fuel distribution during various flight conditions.

In contrast to ejector units, flapper valves function primarily as one-way valves to prevent backflow within the system. Baffles serve a different purpose, which is to minimize fuel sloshing within the tank and maintain fuel stability during maneuvers. Fuel pumps, while crucial for circulating fuel to the engine, do not specifically enable the rearward-to-forward fuel transfer as described in the question. Understanding the distinct roles of these components helps clarify the significance of ejector units in the fuel system’s operation.