FAA Aircraft Dispatcher Practice Exam

How does engine anti-ice use affect aircraft performance?

1. It increases fuel efficiency

2. It decreases climb rate

3. It enhances takeoff speed

4. It has no effect on performance

The correct answer is: It decreases climb rate

Engine anti-ice systems are designed to prevent ice accumulation on engine components, particularly on the leading edges where ice formation can disrupt airflow and reduce engine performance. When an aircraft operates in conditions where ice could form, such as during flight through clouds at low temperatures, the anti-ice system must be activated, which can lead to increased fuel consumption and a change in engine performance characteristics. The activation of the engine anti-ice system often causes a reduction in the engine's thrust output due to the additional energy required to heat the engine components and keep ice from forming. Consequently, this results in a decreased climb rate because the aircraft has less available thrust to overcome weight and drag, particularly during critical phases of flight like takeoff and climb. Understanding this impact is crucial for dispatchers, as they need to plan for these performance changes in order to ensure the safety and efficiency of flight operations. While options that suggest improvements in fuel efficiency or takeoff speed would likely misrepresent the realities of increased drag and reduced thrust associated with engine anti-ice use, recognizing that it decreases climb rate aligns with the practical implications on the aircraft's operational capabilities when the system is engaged.