internal object damage
internal object damage (IOD)
Any damage caused to an engine by a loose engine component, or by a part of it, or by a part of materials or components in the intake. This differs from foreign object damage, which is caused by elements external to aircraft, whereas IOD is caused by materials from the engine or intake. In some countries, IOD is FOD (foreign object damage), and there is no separate category.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved