Which is a possible cause of engine failure in flight?

Mechanical failure is indeed a recognized potential cause of engine failure in flight. It encompasses a wide range of issues that can occur within the engine system, such as component fatigue, wear and tear, or a malfunction in engine control systems. Such failures can lead to a loss of engine performance or a complete engine shutdown, posing significant risks during flight.

It's important to note that mechanical failure might manifest in various ways, including abnormal engine readings, unusual noises, or vibrations that may signal underlying problems. Pilots are trained to monitor engine performance closely, and understanding the possibility of mechanical failure helps them prepare for and manage in-flight emergencies effectively.

Other factors like electrical overload and pilot error can impact overall aircraft performance and safety but are not classified as direct mechanical failures of the engine itself. Therefore, mechanical failure remains a significant concern in aviation safety relating specifically to engine operation.