FAA Powerplant Written Practice Test

What function do hydro mechanical fuel control units serve in a turbine engine?

1. A Visual monitoring of fuel levels

2. B Regulation of fuel flow rates

3. C Collection of exhaust samples

4. D Filtering of fuel contaminants

The correct answer is: B Regulation of fuel flow rates

Hydro mechanical fuel control units play a crucial role in turbine engines by regulating fuel flow rates. These units are designed to manage the amount of fuel delivered to the engine's combustion section based on various operating parameters such as engine speed, temperature, and pressure. By accurately controlling the fuel flow, the hydro mechanical fuel control unit ensures optimal engine performance, efficiency, and responsiveness throughout different phases of operation, including start-up, idle, and full power settings. This precise regulation is vital for maintaining the correct air-fuel mixture, which is essential for efficient combustion and engine operation. Without this control, the engine could suffer from poor performance, increased emissions, or even damage due to fuel starvation or flooding. In contrast, visual monitoring of fuel levels, collection of exhaust samples, and filtering of fuel contaminants serve different functions that do not directly relate to the core responsibility of managing fuel flow within the engine.