UP AND OVER U.S. Air Force Senior Master Sgt. Nate Tennyson tackles the 823rd Red Horse Squadron's obstacle course during a Silver Flag exercise on Tyndall Air Force Base, Fla., Nov. 2, 2008. Silver Flag provides contingency training in which airmen from various career fields train and interact in a realistic environment. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 274249-E-SLA34-498.jpg Photo Gallery