Which of the following is an advantage of FADEC over hydromechanical fuel control?

• A. Increases maintenance requirements.
• B. Lacks engine limit protection.
• C. Reduces reliability under extreme conditions.
• D. Provides engine limit protection and repeatable engine transients.

Answer: (D)

FADEC provides precise, computer-controlled fuel metering with sensor feedback and protective logic, which gives real engine limit protection and highly repeatable responses to throttle changes. With electronic control, the system constantly monitors parameters like speed, temperature, and fuel flow and can automatically prevent overspeed or overtemperature by trimming fuel as needed, something a purely mechanical system can’t do as reliably. It also delivers repeatable transients because the same control algorithms run the same way each time, minimizing variations caused by wear, temperature, or hydraulic fluctuations that affect hydromechanical controls. In practice, this combination means the engine stays within safe limits and accelerates or decelerates in a predictable manner, which is why this option is the best choice.