Airman 1st Class Trevor Garrett, a 28th Operations Support Squadron aircrew flight equipment technician, right, fits a gas mask for Chief Master Sgt. Adam Vizi, the 28th Bomb Wing command chief, at Ellsworth Air Force Base, S.D., March 14, 2017. AFE technicians perform a fit test for aircrew to ensure the mask is secure and won’t have any air leaks. (U.S. Air Force photo by Senior Airman Denise Jenson)