Air Force Capt. (Dr.) Katherine Ellis, Staff Sgt. Jamie Bucher and Capt. Andrew Ray Severns participate in Critical Care Air Transport Team (CCATT) Simulation Day training in Walter Reed Bethesda simulation center on Dec. 11. Air Force physicians, nurses and respiratory therapists were able to hone their critical care skills on life-like manikins using virtual reality machines and equipment in the high-tech, state-of-the-art simulation center. (Photo by Bernard S. Little)