Which statement about the primary role of the turbine fuel control unit is accurate?

• A. Schedules fuel flow to meet power demand
• B. Lowers engine torque at idle
• C. Maintains fixed fuel pressure
• D. Regulates exhaust mixture

Answer: (B)

The key function of a turbine fuel control unit is to meter the right amount of fuel to the combustor so the engine can produce the requested power, while keeping speed and temperatures within safe limits. It translates throttle input and real-time engine conditions into a fuel flow schedule, increasing fuel as demand rises and reducing it as demand falls. At idle, reducing fuel flow lowers the turbine speed and the resulting torque, which is why idle torque is managed by the fuel control.

That’s why scheduling fuel flow to meet power demand is the best description of its primary role. The other ideas aren’t the core purpose: fuel pressure is set by the fuel system and can vary within safe limits rather than being fixed by the FCU, and regulating the exhaust mixture isn’t a direct primary function of the fuel control unit—air-fuel ratio is managed through the combination of airflow and fuel metering rather than a separate exhaust-regulation role.