What is the main fuel system's primary function?

• A. To regulate hydraulic pressure for the landing gear.
• B. To manage electrical power generation.
• C. To govern the correct main fuel flow to the combustion section to start and operate from IDLE through MIL power, under all conditions within the envelope.
• D. To provide cooling to the engine.

Answer: (C)

The main task of the main fuel system is to meter and deliver the exact amount of fuel to the engine’s combustion section to start and operate from idle through military power, under all conditions within the flight envelope. It works with the engine control to sense throttle position, RPM, altitude, and temperature, then adjusts fuel flow through pumps and the fuel control unit so the engine receives the right fuel-air mixture for reliable starts, stable idle, and proper power delivery across the full range of flight conditions. This function is distinct from hydraulic, electrical, or cooling systems, which handle landing gear operation, power generation, or engine cooling, respectively.