U.S. Air Force Airman 1st Class Locke Williams, 44th Aircraft Maintenance Unit crew chief, prepares an F-15 Eagle for flight April 19, 2017, at Kadena Air Base, Japan. Crew chiefs play a vital role in ensuring aircraft are ready for flight and pre-flight inspections by the pilot. (U.S. Air Force photo by Senior Airman Lynette M. Rolen)