How is foreign object damage (FOD) defined?

Foreign object damage (FOD) is specifically defined as any damage to aircraft that is caused by foreign objects. This can include items such as tools, debris, or other materials that are not a part of the aircraft but can become hazardous if they come into contact with critical components during operation or maintenance. Understanding this definition emphasizes the importance of FOD prevention practices within aviation operations, as they are designed to protect aircraft from harm that can be caused by objects that do not belong in the environment surrounding aircraft.

The other options presented do not accurately capture the essence of FOD. Damage caused by altitude changes relates to the operational environment rather than external objects, while damage from internal component failures concerns inherent mechanical issues rather than external factors. Wear and tear over time, although a significant factor in aircraft maintenance, does not involve foreign objects and therefore cannot be classified as FOD.