FOB MacKenzie formerly FOB Pacesetter (Samarra East Airbase under Saddam Hussein) was a US Army Forward Operating Base that is located in Northern Iraq approximately 96 kilometers North of Baghdad, and about 12 kilometers Northeast of the Tigris River. The airbase is served by a single long runway. FOB MacKenzie occupies a 18-square-kilometer site and is protected by an 18-kilometer security perimeter. According to the "Gulf War Air Power Survey", there were 12 hardened aircraft shelters at FOB MacKenzie as of 1991. At each end of the main runway are hardened aircraft shelters knowns as "trapezoids" or "Yugos" which were built by Yugoslavian contractors some time prior to 1985.