Air Force Chief of Staff Gen. Mark A. Welsh III shakes hands with Capt. Adriana Valadez, a 433rd Aeromedical Evacuation Squadron flight nurse, highlighted during his Air Force Update keynote address during the Air Force Association's 2013 Air & Space Conference and Technology Exposition Sept. 17, 2013, in Washington, D.C. During his address, Welsh emphasized how each Airman contributes to Global Vigilance, Global Reach and Global Power for America. (U.S. Air Force photo/Michael J. Pausic) (Photo by Michael J. Pausic )