U.S. Air Force Senior Airman David Situ, 7th Equipment Maintenance Squadron nondestructive inspection journeyman, uses an eddy current to inspect a metal part at Dyess Air Force Base, Texas, Oct. 24, 2016. An eddy current causes a localized electric current wherever a component is being inspected. Even if there are cracks invisible to the naked eye, the reader can pinpoint them. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)