EIELSON AIR FORCE BASE, Alaska--The sun sets on a group of B-1B Lancers from Ellsworth Air Force Base, South Dakota, on the flightline here April 16 during Red Flag-Alaska 07-1. Red Flag-Alaska enables aviation units to sharpen their combat skills by flying ten simulated combat sorties in a realistic threat environment. Additionally, the training allows them to exchange tactics, techniques, and procedures and improve interoperability. (U.S. Air Force photo by Senior Airman Justin Weaver).