Private Pilot License (PPL) Aerodynamics Practice Exam

Why is frost considered a hazard to flight?

1. It increases fuel consumption

2. It reduces visibility

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

4. It affects the engine performance

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

Frost is considered a significant hazard to flight primarily because it spoils the smooth flow of air over the wings. When frost accumulates on the wing surfaces, it disrupts the intended aerodynamic profile of the wings. Aircraft wings rely on smooth airflow to generate lift; any irregularities in the surface can lead to increased drag and turbulence, which negatively impacts the aircraft's performance. The presence of frost can cause an early stall during takeoff or landing by reducing the effective lift generated at a given angle of attack. While increased fuel consumption, reduced visibility, and possible engine performance issues are important considerations in aviation safety, the immediate and critical impact of frost relates directly to its effect on the aerodynamic properties of the aircraft, particularly how air flows over and under the wings. Consequently, the hazards posed by frost to flight are centered around the diminished aerodynamic efficiency and safety of the aircraft.