If a reciprocating engine has a major internal failure, which components must always be replaced?

In the event of a major internal failure in a reciprocating engine, the oil cooler and propeller governor are critical components that should always be replaced. This is due to the potential for contamination of the oil system and the possibility that debris from the engine may have circulated through these components, compromising their performance and reliability.

The oil cooler plays a vital role in maintaining the engine's temperature by regulating oil temperature. If it has been subjected to extreme conditions following an internal failure, it may develop clogs or leaks, rendering it ineffective. Additionally, any debris that has entered the oil system could cause damage to the oil cooler itself.

The propeller governor is responsible for controlling the propeller speed by managing engine power and adjusting the propeller blade pitch accordingly. Any internal failure could affect its calibration and responsiveness, leading to unsafe operations. Thus, to ensure reliable and safe engine performance, replacing the oil cooler and propeller governor is essential after a major internal failure.