AAR provides major maintenance inspections, line maintenance, aircraft modifications and upgrades to the major regional and cargo airline fleets, and for the U.S military and government agencies. AAR currently operates six major maintenance facilities with more than 5,000 employees. The company was ranked as 3rd largest MRO in the world, 1st largest MRO in USA according to a 2012 study conducted by Aviation Week’s Overhaul and Maintenance magazine.