ELLSWORTH AIR FORCE BASE, S.D. -- Airman 1st Class David McMillen, 28th Civil Engineer Squadron, heating, ventilation and air-conditioning apprentice, secures a simulated patient to a stretcher during a Phase II Operational Readiness Exercise, Sept. 16. Airmen test their skills during the exercise in a simulated deployed environment. (U.S. Air Force photo/Airman 1st Class Anthony Sanchelli)