CE Field Exercise
Staff Sergeant Helen Hernandez of the 149th Civil Engineering Squadron, 149th Fighter Wing, Texas Air National Guard, assists Airman First Class Jeremy Ortega with a chemical mask during a field readiness exercise on February 7, 2009. The exercise took place at Lackland Air Force Base, Medina Annex, San Antonio, Texas. (U.S. Air Force Photo by Master Sgt. Robert Shelley)