The two sections of the fuel control unit are which two types?

• A. Manual control and hydro-mechanical control
• B. Manual control and hydraulic control
• C. Automatic control and hydro-mechanical control
• D. Automatic control and hydraulic control

Answer: (A)

The fuel control unit is built around two functions: giving the pilot direct input and providing automatic regulation. The manual control part provides a direct, mechanical link from the throttle to the fuel metering device, so moving the throttle changes fuel flow immediately. The hydro-mechanical control part uses hydraulic pressure to automatically adjust fuel flow based on engine conditions like speed and pressure, coordinating metering to keep the engine running smoothly and safely. Together, these two sections—one for manual input and one for automatic hydraulic regulation—describe how the FCU operates.