FAA Powerplant Written Practice Test

In the context of FADEC, what is a major advantage of not having a hydro mechanical backup?

1. A Reduces maintenance costs

2. B Avoids system complexity

3. C Provides faster response times

4. D Increases fuel efficiency

The correct answer is: C Provides faster response times

The advantage of not having a hydro mechanical backup in a FADEC (Full Authority Digital Engine Control) system significantly contributes to faster response times. In a FADEC system, all control functions are managed electronically, allowing for rapid adjustments and precise engine control without the delays that can occur in a hydro mechanical system. When a backup system is not present, the engine control logic operates solely through digital electronics, which can react to changes in operating conditions much more quickly than a mechanical system. This quick response is essential, especially in dynamic conditions such as sudden throttle changes or variations in altitude, where an aircraft needs to adjust engine parameters promptly to maintain performance and safety. In contrast to other considerations like maintenance costs, system complexity, or fuel efficiency, the direct linking of electronic sensors and actuators enhances the speed of control inputs and outputs, leading to improved engine performance and responsiveness.