U.S. Air Force Airman 1st Class Dakota Martin, 1st Maintenance Squadron nondestructive inspection apprentice, inspects cracks under a black light at Joint Base Langley-Eustis, Va., Nov. 15, 2017. The parts are soaked in liquid penetrant, which seeps into cracks, making them visible during inspection under a black light. (U.S. Air Force photo by Airman 1st Class Alexandra Singer)