What is considered the most dangerous aspect of structural icing?

Structural icing is a critical concern for pilots as it alters the airfoil shape of the wings, leading to several aerodynamic issues. Ice accumulation on wings disrupts the smooth airflow over the airfoil, increasing drag and reducing lift. This change in the airfoil's performance can significantly impact a flight's safety and control, leading to hazardous situations such as stalls or unexpected changes in flight characteristics.

While other options present valid concerns linked to flying in icing conditions, they do not capture the fundamental issue posed by ice accumulation on the airfoil itself. Loss of equilibrium and delayed reaction times can be influenced by ice, but the primary threat remains the alteration to the wing's aerodynamics. Likewise, increased fuel consumption secondary to the additional drag created by ice is a concern, but it is the aerodynamic integrity that most critically jeopardizes flight safety. Thus, the transformation of the wing's airfoil shape is the most dangerous aspect of structural icing.