Plain English Meaning

Damage caused when stray bits of stuff — rocks, hardware, tools, trash, ice, even birds — get sucked into an engine or hit a propeller, tire, or airframe. The same letters are also used for the loose junk itself.

Full Definition

Damage to an aircraft, engine, propeller, or related equipment caused by loose objects on the ground or in the airflow path — such as stones, bolts, tools, ramp debris, ice, or birds — being struck by, ingested into, or thrown against aircraft components. The term is also commonly used to refer to the loose objects themselves (foreign object debris) that pose this hazard.

Context Anchor

Pilots encounter FOD concerns during preflight inspection, engine start, taxi, training on the parking area, and runway operations.

Derivation

The phrase combines three English words: ‘foreign’ (not there), ‘object’ (a thing), and ‘damage’ (harm). It became a term because even small, -of-place items can cause large amounts of harm to aircraft, especially to spinning and .