What is a common method to prevent induction system ice in a reciprocating engine?

Preventing induction system ice in a reciprocating engine is crucial for maintaining optimal engine performance and ensuring safety during flight. Preheating the induction air is an effective method for this purpose. When air enters the induction system, it can cool and cause moisture to freeze, leading to ice formation that can restrict airflow into the engine. By preheating the air before it enters the induction system, the temperature of the air is elevated, which reduces the chances of water vapor condensing and freezing.

This approach is commonly achieved through the use of heat exchangers or heated air from the exhaust system. Preheating not only prevents ice formation but also helps maintain engine performance by ensuring a consistent airflow and fuel mixture.

Other options may not address the root cause of induction icing effectively. Increasing engine RPM can potentially warm the engine components due to higher airflow and engine operation, but it does not directly target the temperature of the intake air. Changing fuel types is not a practical solution for combating induction icing, as ice formation is primarily influenced by air temperature and humidity. Fully opening the throttle could increase airflow but might not help with the temperature of the incoming air, which is critical in preventing ice.