FAA Ground School Practice Test

Why is frost considered a hazard to flight?

1. It increases drag significantly

2. It blocks the pilot’s visibility

3. It spoils the smooth flow of air over the wings

4. It elevates landing gear risk

The correct answer is: It spoils the smooth flow of air over the wings

Frost is considered a hazard to flight primarily because it spoils the smooth flow of air over the wings. When frost forms on an aircraft, it disrupts the airflow, leading to turbulent conditions. This can severely impact the wing's aerodynamic properties, especially its lift capabilities. The presence of frost creates a rougher surface compared to a clean wing, which can lead to an increased stall speed and a higher likelihood of stalling at lower speeds. The aerodynamic efficiency is critical for safe flight, and any disturbance to the smooth contour of the wing can significantly affect performance during crucial phases of flight such as takeoff and landing. Maintaining proper airflow over the wings is essential for ensuring that the aircraft operates effectively and safely. Factors like increased drag, visibility issues for the pilot, and risks associated with landing gear are important, but the primary concern with frost is its direct impact on the wing's airflow and consequently, the overall flight performance.