Tech. Sgt. Jeff Mercer and Senior Airman Zina Wright guard a defensive fighting position during Expeditionary Combat Skills Training on Charleston AFB Aug. 26. ECST is required for Airmen who are deploying to hostile areas where combat knowledge and skills are required. Sergeant Mercer and Airman Wright are with the 437th Logistics Readiness Squadron. (U.S. Air Force photo/Airman 1st Class Timothy Taylor)