What are the four levels of icing intensity classified in aviation?

The classification of icing intensity in aviation is crucial for pilot awareness and safety during flight operations. The correct four levels are trace, light, moderate, and severe.

"Trace" icing refers to very minimal contamination, where it might not require any immediate action but indicates that icing is present. "Light" icing occurs when icing begins to accumulate, but it will not significantly affect aircraft performance. "Moderate" icing represents an accumulation that may require the pilot to take action to maintain control, and it can affect performance more noticeably. Finally, "severe" icing poses a significant hazard as it leads to rapid accumulation that can critically impair the aircraft's ability to fly safely.

Understanding these categories helps pilots make informed decisions regarding altitude adjustments, changes in route, and whether to depart or continue a flight based on atmospheric conditions. Other classifications presented do not accurately reflect the established terminology used in aviation for icing intensity.