Airman 1st Class Gabriel Henry yells to Airman 1st Class Brian Allen, both crew chiefs assigned to the 28th Aircraft Maintenance Squadron, Ellsworth Air Force Base, S.D., during Red Flag 15-2 at Nellis AFB, Nev., March 10, 2015. Any personnel located in the area of an aircraft with an engine on must wear hearing protection among other personal protective equipment. (U.S. Air Force photo by Staff Sgt. Siuta B. Ika)