U.S. Army 1st Sgt. Christa Petersen, with Echo Company,

U.S. Army 1st Sgt. Christa Petersen, with Echo Company, 1st Battalion, 507th Parachute Infantry Regiment, gives the sound off for equipment check during Sustained Airborne Training in preparation for the 75th Anniversary Airborne School jump at William T. drop zone in Ft. Benning, Ga., Aug. 14, 2015. The 1-507th Parachute Infantry Regiment(PIR) Battalion celebrates 75 years of the U.S. Army Airborne School and the commemoration of the last qualifying jump of the first airborne test platoon on Aug. 15, 1940. (U.S. Army Photo by Spc. Joshua Talley/ Released)