What is the primary function of fuel pumps in an aircraft fuel system?

The primary function of fuel pumps in an aircraft fuel system is to transfer fuel from the tanks to the engines and maintain appropriate fuel pressure. This is crucial for ensuring that the engines receive a consistent and adequate supply of fuel for efficient combustion and reliable performance.

Fuel pumps operate by generating the necessary pressure to move fuel through the various components of the fuel system, including filters and lines, before it reaches the engine. They help maintain a steady flow of fuel, which is particularly important during different phases of flight such as takeoff, cruising, and landing, where fuel demand can vary significantly.

Furthermore, by maintaining proper fuel pressure, the pumps prevent issues like vapor lock, which can occur if fuel does not flow smoothly or if pressure drops too low. This function is essential for ensuring the aircraft’s engines can operate safely and efficiently, contributing to overall operational reliability and performance.

Other options describe functions that are not the primary role of fuel pumps. For instance, while some systems may manage fuel cooling or prevent evaporation, those tasks typically involve other components within the aircraft's fuel system rather than the direct function of fuel pumps. Additionally, storing excess fuel is not a function handled by fuel pumps but rather pertains to the design of the fuel tanks themselves.