1st Lt. Mitchell Simonsen, left, and Capt. Charlie Murphy, C-17 Globemaster III pilots with the 3rd Airlift Squadron, practice aerial refueling in a C-17 simulator Oct. 20, 2011, at Dover Air Force Base, Del. The pilot simulator runs more than 18 hours a day training 12 students a day. (U.S. Air Force photo/Roland Balik)