What type of icing is considered the most dangerous due to its heavy weight?

Clear icing is regarded as the most dangerous type of icing because it forms a heavy, glossy layer on the aircraft's surfaces when supercooled water droplets freeze upon impact. This type of icing can accumulate quickly and leads to significant weight increase. The density of clear ice compared to other types, such as rime or mixed icing, makes it particularly hazardous, as it can severely interfere with the aircraft's performance and handling characteristics.

In addition to its weight, clear icing often occurs at higher altitudes and temperatures than rime icing, which can make it less detectable until it has already built up on the aircraft. It forms a smooth layer that can disrupt airflow over wings and control surfaces, leading to increased stall speeds and diminished control authority. Therefore, its weight and aerodynamic ramifications make clear icing a critical hazard during flight operations.