Charleston Airmen patrol the perimeter of the Expeditionary Combat Skills Training area on Charleston AFB April 8. ECST is required for Airmen who are deploying to hostile areas where combat knowledge and skills are required. This training occurs biweekly. (U.S. Air Force photo/Senior Airman Katie Gieratz)

Master Sgt. Joe Garza instructs a fellow Team Charleston member what do to during an attack while participating in the Expeditionary Combat Skills Training exercise on Charleston AFB April 8. ECST is required for Airmen who are deploying to hostile areas where combat knowledge and skills are required. On average there are 40 students in the classes. Sergeant Garza is with the 437th Logistics Readiness Squadron.(U.S. Air Force photo/Senior Airman Katie Gieratz)

Staff Sgt. Fernando Olivas speaks to Team Charleston deployers about combat during Expeditionary Combat Skills Training on Charleston AFB April 8. ECST is required for Airmen who are deploying to hostile areas where combat knowledge and skills are required. ECST began on Charleston AFB in September of 2005. Sergeant Olivas is with the 437th Security Forces Squadron. (U.S. Air Force photo/Senior Airman Katie Gieratz)

Tech. Sgt. Jason Kronenberg cleans his weapon during Expeditionary Combat Skills Training on Charleston AFB April 8. ECST is required for Airmen who are deploying to hostile areas where combat knowledge and skills are required. Sergeant Kronenberg is with the 437th Maintenance Group. (U.S. Air Force photo/Senior airman Katie Gieratz)