Firefighters from the 307th Civil Engineer Squadron at Barksdale Air Force Base, La., attack a controlled burn on an aircraft fire training simulator during the May Unit Training Assembly. Barksdale Air Force Base is one of the bases equipped with an aircraft fire training simulator allowing firefighters to recreate different emergency scenarios without burning up an aircraft every time they practice. (U.S. Air Force photo by Master Sgt. Laura Siebert/Released)