U.S. Air Force Airman 1st Class Ryan Hess, 20th Equipment Maintenance Squadron non-destructive inspection apprentice, dips metal parts into penetrant at Shaw Air Force Base, S.C., Jan. 15, 2019. The penetrant is used to seep into any small cracks not easily seen by the human eye. (U.S. Air Force photo by Senior Airman BrieAnna Stillman)