U.S. Air Force Airmen perform clear a building during Air Combat Command’s Defender Challenge team selection at Joint Base Langley-Eustis, Virginia, August 21, 2018. Nine Airmen competed over a five-day-period in various events, including a ruck march, land navigation, and M4 carbine and M9 pistol tactics and proficiencies. (U.S. Air Force photo by Airman 1st Class Anthony Nin Leclerec)