First Lt. Thomas McQueeny, 349th Air Refueling Squadron KC-135 Stratotanker co-pilot, dons chemical gear in preparation for aircrew contamination control area training Aug. 24, 2017, at McConnell Air Force Base, Kan. The ACCA establishes a location to provide detection, contamination control and processing provisions for aircrew members into a toxic-free environment. (U.S. Air Force photo/Airman 1st Class Alan Ricker)