U.S. Air Force Airman 1st Class Andrew Roberts, aircraft inspection apprentice assigned to the 18th Equipment Maintenance Squadron, unscrews a bolt from a KC-135 Stratotanker during an isochronal inspection at Kadena Air Base, Japan, May 22, 2019. Each aircraft in Kadena’s KC-135 Stratotanker undergoes an inspection every two years to make sure that they are performing optimally. (U.S. Air Force photo by Naoto Anazawa)