Airman 1st Class Charles Mills, 28th Maintenance Squadron nondestructive inspection technician, inspects a hydraulic accumulator piece under black lights at Ellsworth Air Force Base, S.D., Aug. 9, 2013. Under black light, imperfections appear as green lines allowing NDI to determine the length and location of cracks, aiding in enhancing the maintenance and performance of the B-1. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)