Maj. Matt Armstrong, 62nd Operations Group executive officer, briefs Army Gen. Martin Dempsey, Chairman of the Joint Chiefs of Staff, Oct. 4, 2012, about McChord Field's involvement in Operation Deep Freeze, at Joint Base Lewis-McChord, Wash. The United States' most senior military official visited JBLM to get a better understanding of the various missions performed by McChord Field Airmen. (U.S. Air Force photo/Staff Sgt. Sean Tobin)