What is a characteristic of FADEC engine systems?

FADEC, which stands for Full Authority Digital Engine Control, is an advanced electronic system that manages all aspects of engine performance, including ignition and fuel control. As a solid-state system, FADEC utilizes digital computations to optimize engine operations, ensuring precise fuel-to-air mixing and ignition timing, regardless of operating conditions. This characteristic enhances the engine's efficiency, reliability, and performance while reducing pilot workload by automating many control aspects.

In contrast, the other options describe systems or characteristics that are either outdated or not applicable to FADEC. Mechanical throttle control systems are less efficient and can hinder the capabilities that digital systems provide. Vacuum pressure control is typically used in older carbureted systems and does not align with the modern electronic nature of FADEC. While it's true that FADEC systems are commonly used in turbine engines, they are not exclusive to them, as some piston engines may also utilize similar electronic control systems for fuel and power management. Overall, option B accurately reflects the sophisticated nature of FADEC as a solid-state system dedicated to engine control.