ELLSWORTH AIR FORCE BASE, S.D. -- Capt. Kaylene Giri, a 34th Bomb Squadron weapons systems officer instructor, proceeds through a preflight checklist at her WSO crew station in a B-1B Lancer, Oct. 15, 2009. Captain Giri, along with another WSO and the two pilots, perform preflight checks to ensure all systems are functioning before every mission. (U.S. Air Force photo/Airman 1st Class Corey Hook)