Which icing type affects the engine's induction system?

• A. Induction icing
• B. Structural icing
• C. Instrument icing
• D. Thermal icing

Answer: (A)

Ice forming inside the engine’s air intake is the type that directly affects the induction system. When moist air entering the engine cools, water droplets can freeze in the intake, carburetor or throttle body. That ice narrows or blocks the passage, reducing the amount of air reaching the cylinders. With less air for combustion, engine power drops and the engine can run rough or even quit if the icing is severe. This is specifically about the induction path, not about other parts of the airplane.

Structural icing, by contrast, forms on surfaces like wings and the fuselage, increasing weight and disrupting aerodynamics. Instrument icing happens on cockpit instruments, potentially obscuring readings. Thermal icing isn’t the category associated with the engine’s intake path.