What is Structural icing?

• A. The accumulation of ice on the exterior of the aircraft.
• B. The frosting of cabin interior surfaces.
• C. Ice formation on engine compressors only.
• D. Ice buildup on the instrument dials only.

Answer: (A)

Structural icing means ice that forms on the exterior surfaces of the airplane—wings, tail, fuselage, and propellers—altering the shape of those surfaces and adding weight. It happens when moist air freezes on contact with the airplane in freezing or near-freezing conditions, often in clouds or with supercooled droplets. This ice changes the aerodynamic profile, roughens the surface, increases drag, and raises stall speed, which can reduce lift and even lead to loss of control if it becomes heavy. It’s a flight safety concern that covers ice on the outside of the aircraft and is distinct from icing inside the cabin, on engine components, or on instruments.