Which publication is essential for checking an engine’s normal operation?

The OEM (Original Equipment Manufacturer) maintenance manual is essential for checking an engine's normal operation because it provides the most detailed and specific information about the engine's design, systems, and operational procedures. This manual includes critical data such as normal operating parameters, inspection intervals, maintenance procedures, and troubleshooting guides that are tailored to the specific engine model.

Having access to this manual ensures that personnel can follow the manufacturer's recommendations for normal operation, maintenance practices, and safety precautions. Therefore, it serves as a vital reference for understanding how to monitor and maintain engine performance effectively.

In contrast, service bulletins, while important for updates and specific issues relating to an engine, do not provide comprehensive operational guidance. Technical service manuals may also offer valuable information but can be broader and not specifically tailored to a single engine model. Safety inspection checklists are focused on safe operation practices and may not include detailed operational data necessary for assessing normal engine function.