Air Combat Command Team member Airman 1st Class Justin D. Johnston flips over The Dirty Name obstacle during the fitness challenge event of Defender Challenge '99 at Lackland Air Force Base, Texas, on Nov. 1, 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.