Air Force Staff Sgt. Albert Brown communicates with the pilots of an E-3 Sentry prior to take off at Joint Base Elmendorf-Richardson, Alaska, during Exercise Polar Force 12-7 Oct. 24, 2012. The exercise was designed to test base preparedness for various scenarios.Brown is a 962nd Aircraft Maintenance Unit E-3 crew chief from Redding, Calif. (U.S. Air Force photo/Staff Sgt. Robert Barnett)