General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

What happens if one wing anti-ice valve fails closed?

1. The other wing anti-ice valve stays open

2. Both wing anti-ice valves shut automatically

3. The aircraft will lose lift

4. The flight computer will alert the crew

The correct answer is: Both wing anti-ice valves shut automatically

When one wing anti-ice valve fails closed, the correct outcome is that both wing anti-ice valves shut automatically. This is typically a safety feature designed to prevent an imbalance in the aircraft which can occur if one wing remains heated while the other does not. Anti-ice systems are critical in maintaining aerodynamic performance, especially in ice-prone conditions, and having both valves shut helps ensure that the flight control and handling characteristics remain stable. The functioning of the anti-ice system is important for preventing ice accumulation, which can lead to increased drag and decreased lift. If one valve remains open while the other fails, the wing can experience unequal heating, potentially leading to serious aerodynamic issues. Therefore, the automatic closure of both valves serves as a precaution to safeguard the aircraft's performance and ensure safety. Understanding this system's failure modes is crucial for pilots and maintenance crews, as it highlights the importance of system redundancy and how it contributes to overall flight safety.