What action should be taken if a turbine engine experiences an overspeed?

In the event of a turbine engine experiencing an overspeed condition, referring to the maintenance manual for required procedures is the most appropriate action. The maintenance manual is specifically designed to provide detailed and authoritative guidance for addressing various issues that can arise during engine operation, including overspeed incidents. This resource will include the manufacturer's recommended steps for safely bringing the engine back to a controlled state, as well as any necessary actions to ensure operational safety and engine integrity.

Utilizing the maintenance manual allows technicians or pilots to follow established protocols that have been developed based on extensive testing and engineering analysis; this ensures that the response to an overspeed situation is methodical and thorough. Each turbine engine may have unique characteristics or safety features, so the specific procedures outlined in the manual are critical to effectively managing the situation.

The other options present risks or insufficient action. Restarting the engine immediately could exacerbate any existing issues, continuing normal operation during an overspeed puts the aircraft and crew in jeopardy, and performing a simple visual check may miss underlying mechanical problems that require in-depth analysis and intervention. Thus, consulting the maintenance manual is the best practice to ensure safe handling of an overspeed situation in a turbine engine.