U.S. Service members listen to U.S. Air Force Chief Master Sgt. John Thompson, 480th Intelligence, Surveillance and Reconnaissance command chief, talk about his experiences as a young Airman during a first sergeants seminar at Langley Air Force Base, Va., May 8, 2015. Only master sergeants, senior master sergeants and chief master sergeants can apply to be a first sergeant because they are in the top tier of the enlisted rank structure. (U.S. Air Force photo by Senior Airman Breonna Veal/Released)