The U.S. Air Force Air Demonstration Squadron, known as the Thunderbirds, move from trail position into diamond formation during Aviation Nation 2012 over Nellis Air Force Base, Nev., Nov. 11, 2012. The U.S. Air Force Air Demonstration Squadron, known as the Thunderbirds, move from trail position into diamond formation during Aviation Nation 2012 over Nellis Air Force Base, Nev., Nov. 11, 2012. SHARE: Download: Full Size (2.23 MB) Tags: Photo Essays Credit: VIRIN: 697035-Z-VNH66-698.jpg Photo Gallery