How do the Primary Jet Pumps function once the system is initiated?

The primary jet pumps play a crucial role in the fuel management system by acting as the primary fuel feed pumps. Once the system is initiated, these pumps are responsible for drawing fuel from the fuel tanks and delivering it to the engines. This process ensures that the engines receive a consistent and adequate supply of fuel, which is vital for their operation during flight.

The operational mechanism involves using the pressure differential created by the engine-driven fuel pumps and the Venturi effect, allowing fuel to be pumped efficiently from the tanks. This system is designed to ensure that fuel reaches the engines at all stages of operation, including climb, cruise, and descent, contributing to overall aircraft performance and safety.

This function distinguishes the primary jet pumps from emergency backup systems, which serve as alternatives in case of failure of the primary systems. Additionally, the primary jet pumps operate continuously during flight, not just during specific ground checks, and they do rely on the engine pumps to some extent for proper functioning, making them integral to the fuel delivery system.