The United States Air Force Air Demonstration Squadron Thunderbirds, move from trail position into diamond formation over Nellis during the 2011 Aviation Nation Nellis Open House Nov. 12, at Nellis Air Force Base, Nev. Aviation Nation celebrates 70 years of airpower in Las Vegas and the Air Force’s accomplishments in air, space and cyberspace. (Senior Master Sgt. Kevin Gruenwald/U.S. Air Force)