Crew chiefs
U.S. Air Force Senior Airman Mark Perko, 386th Expeditionary Aircraft Maintenance Squadron C-130H crew chief, performs a seven-day inspection on a C-130 engine prop Jan. 22, 2010 at an air base in Southwest Asia. Airman Perko is deployed from Dyess Air Force Base, Texas. (U.S. Air Force photo by Staff Sgt. Lakisha A. Croley/Released)