FAA Ground School Practice Test

How does frost affect the lifting surfaces of an airplane on takeoff?

1. It enhances the lifting capability

2. It causes the airplane to become airborne at lower speeds

3. It may prevent the airplane from becoming airborne at normal takeoff speed

4. It has no effect on the takeoff process

The correct answer is: It may prevent the airplane from becoming airborne at normal takeoff speed

Frost on the lifting surfaces of an airplane significantly disrupts the airflow over the wings, which is essential for generating lift. When there is frost, it creates a rough surface that alters the smooth flow of air required for optimal lift. This roughness can lead to an early stall condition, preventing the wing from reaching the necessary lift at normal takeoff speed. Consequently, the airplane may not become airborne, or it could require an increased takeoff distance, making it crucial for pilots to ensure that wings and other lifting surfaces are free from frost, ice, or snow before takeoff. The other options do not accurately reflect the impact of frost. For instance, frost does not enhance lifting capability or allow for takeoff at lower speeds; rather, it diminishes lift. Additionally, the assertion that it has no effect on the takeoff process overlooks the critical impact frost can have on flight performance and safety.