What type of icing disrupts the smooth flow of air, increasing drag and decreasing lift?

The answer is particularly relevant to the effects of different types of icing on aircraft performance. Structural icing occurs when supercooled water droplets freeze on contact with an aircraft's surfaces. This type of icing can create a rough surface, which disrupts the smooth flow of air over the wings and aerodynamic surfaces.

When the airflow is disrupted, it significantly affects the aircraft's aerodynamics. The increased drag due to the roughened surfaces makes it harder for the aircraft to maintain speed, while the decreased lift impacts its ability to stay airborne. The combination of higher drag and lower lift can lead to a more challenging flight experience and, in severe cases, can compromise the aircraft's ability to maintain controlled flight.

In contrast, other types of icing have different characteristics and effects. Mixed icing can present a combination of clear and rime icing conditions, while clear icing tends to form a smooth but heavy layer that may not disrupt airflow as dramatically. Rime icing, on the other hand, forms a rough layer but often is less severe in terms of weight and aerodynamic disruption compared to structural icing. Understanding these distinctions is essential for pilots and air traffic controllers to ensure safe operations in winter weather conditions.