What is the primary function of fuel boost pumps in aircraft fuel systems?

The primary function of fuel boost pumps in aircraft fuel systems is to provide a positive flow of fuel to the engine. These pumps are critical, especially during engine start operations, as they help maintain adequate fuel pressure and ensure a consistent fuel supply to the engine. By providing this positive flow, the boost pumps prevent fuel vaporization within the lines and aid in overcoming potential fuel line restrictions, ensuring that the engines receive the necessary fuel for proper operation.

While other components and systems in the fuel system contribute to fuel temperature regulation, filtration, and fuel transfer between tanks, these tasks are not the primary role of boost pumps. Instead, their design focuses on enhancing fuel delivery to the engines, which is essential for maintaining engine performance and reliability, especially under varying flight conditions and altitudes.