AAR Corp is engaged in providing products and services to aviation, government, and defense market. It operates in two segments namely Aviation Services and Expeditionary Services. The Aviation Services segment consists of aftermarket support and services businesses that provide spares and maintenance support for aircraft operated by it's commercial and government/defense customers. The Expeditionary Services segment consists of businesses that provide products and services supporting the movement of equipment and personnel by the U.S. Department of Defense, foreign governments, and non-governmental organizations. It generates a majority of its revenue from the Aviation Services Segment.