What impacts the aerodynamic performance of an aircraft the most regarding frost?

The most significant impact of frost on an aircraft’s aerodynamic performance is related to how it changes the airflow over the wing. When frost accumulates on the wing's surface, it disrupts the smooth airflow necessary for optimal lift and drag characteristics. While the weight of the aircraft does change slightly with frost accumulation, the more critical factor affecting performance is the adverse change in aerodynamic efficiency.

Frost alters the wing's profile by creating a rough surface, which can lead to earlier flow separation. This results in decreased lift and increased drag, not only affecting the aircraft's performance during takeoff and landing but also throughout its flight. Because of this impact on aerodynamic shape, the aerodynamic performance is significantly compromised.

The idea that frost does not change the aerodynamic shape of the wing is incorrect. Frost may not change the general outline of the wing, but it fundamentally alters the effective shape regarding airflow characteristics, making it a crucial consideration for pilots and engineers when addressing aircraft performance under icy conditions.