Final answer:
Engine FOD refers to damage caused by the ingestion of foreign objects that are not supposed to be in an aircraft engine, which can lead to significant repair costs and safety risks.
Step-by-step explanation:
Engine FOD, which stands for Foreign Object Damage, is defined as damage caused by ingestion of objects not native or inherent to the engine. This type of damage commonly occurs when an aircraft engine ingests debris such as rocks, metal particles, or even birds, that are not meant to be in the engine's airflow. Engine FOD can lead to serious malfunctions, costly repairs, and potential safety hazards. Examples of FOD include everything from small rocks and loose hardware to wildlife strikes during aircraft takeoff or landing. Preventing engine FOD is crucial, and it involves careful maintenance, regular inspections, and adherence to stringent operational protocols on runways and airfields.