A U.S. Air Force F-22 Raptor, departs for a training mission during the U.S. Air Force Weapons School mission employment exercise Dec. 7, at Nellis Air Force Base, Nev. The two-week-long mission employment phase is the final part of a five-and-a-half-month Weapons School graduate course that showcases the students newly acquired skills to test their ability to plan, execute and lead complex missions.