FORT POLK, La. – From left: Senior Airman Chase Litvan, Staff Sgt. Josh Arias and Staff Sgt. Will Doherty, U.S. Air Force combat controllers from the 21st Special Tactics Squadron, Fort Bragg, N.C. conduct air traffic control operations on the edge of the Geronimo Landing Zone at Fort Polk, La. during Joint Readiness Training Center rotation 13-09, Aug. 20, 2013. Combat Controllers are special operations forces and certified FAA air traffic controllers whose mission is to deploy, undetected, into combat and hostile environments to establish assault zones or airfields, while simultaneously conducting air traffic control, fire support, command and control, direct action, counter-terrorism, foreign internal defense, humanitarian assistance, and special reconnaissance.