Which aircraft system is directly responsible for controlling engine thrust?

The propulsion system is the one directly responsible for controlling engine thrust. This system encompasses all components related to the engine, including the engines themselves (whether they are turbojet, turbofan, or propeller-driven) and the mechanisms that control how much thrust is produced during operation. By manipulating variables such as fuel flow and engine settings, the propulsion system effectively manages thrust levels to meet the requirements for various phases of flight, such as takeoff, cruising, and landing.

The flight control system, while essential for managing the aircraft's overall flight characteristics, does so by adjusting flight control surfaces rather than directly modulating engine thrust. The electrical system provides power for various aircraft functions but does not control thrust directly. The hydraulic system operates mechanical components and flight control surfaces as well, influencing aircraft maneuverability and responsiveness, but it does not manage the engine thrust itself. Thus, the propulsion system is the dedicated system that directly controls and regulates thrust output.