What is the purpose of a FADEC system in a gas turbine engine?

• A. A digital electronic fuel control that operates during all engine operations, includes the electronic engine control and functions with the flight management computer.
• B. A hydraulic power management unit for the engine.
• C. An analog ignition timing system.
• D. A mechanical fuel metering valve with manual overrides.

Answer: (A)

FADEC is a full-authority digital electronic control for a gas turbine engine. Its primary role is to manage fuel flow and engine operating parameters throughout every phase of operation, from start through idle to max power and shutdown. It uses a network of sensors (temperature, pressures, speeds, fuel flow, etc.) to run a digital control algorithm that determines the exact fuel metering needed for each condition, while enforcing safety limits and protecting the engine. It handles start sequencing, prevents over-temperature or over-speed conditions, and coordinates with the flight management system to optimize performance and efficiency. This digital, integrated control replaces older hydraulic or mechanical controls, which is why the other options—hydraulic power management, analog ignition timing, or a mechanical metering valve with manual overrides—do not describe FADEC.