Level 3 anti icing is powered by which system?

• A. Electrically powered
• B. Probes and sensors (Permanent)
• C. Pneumatics powered by engine bleed air
• D. Level 1 and 2 anti icing

Answer: (C)

Level 3 anti-icing uses a pneumatic system powered by engine bleed air. In the most demanding icing conditions, this setup provides a strong, continuous supply of hot air to critical surfaces—like wing leading edges and engine nacelles—through a network of ducts and valves controlled by the bleed-air system. The heat from the bleed air prevents ice from forming or grows off on these surfaces more effectively than smaller electrical heaters can in heavy icing.

Electrical heating is typically associated with lighter or more localized anti-icing tasks, such as certain sensors or probes, and is not the power source for Level 3 protection. Probes and sensors themselves aren’t a power source, and Level 1 or 2 references describe the level of protection, not the power system. So, for Level 3, the pneumatic, bleed-air–powered approach is what provides the required protection.