Airman 1st Class David Betchley, an aircraft electrical and environmental systems journeyman assigned to the 28th Maintenance Squadron, changes a volt amp sensor on a B-1 bomber at Ellsworth Air Force Base, S.D., March 8, 2017. After every 800 flight hours, Ellsworth’s bombers are sent to hangar 73 to receive an in-depth inspection process that lasts over the course of 20 days. (U.S. Air Force photo by Airman 1st Class Denise M. Jenson)