Competitors from the 11th Wing run in full chemical gear during the Combat Rifle event of Defender Challenge '99. Competitors from the 11th Wing run in full chemical gear during the Combat Rifle event of Defender Challenge '99 at Lackland Air Force Base, Texas, on Nov. 3, 1999. Defender Challenge is an all-star competition featuring Security Forces from Air Force major commands and the Royal Air Force Regiment. Teams compete in a fitness challenge, handgun events, combat rifle, combat weapons and nighttime tactical events. SHARE: Download: Full Size (0.09 MB) Credit: VIRIN: 287043-Q-WPS54-179.jpg Photo Gallery