Senior Airman Santiago De La Rosa, 33rd Maintenance Squadron nondestructive inspection journeyman, checks the readings on a Sonic 1200 unit during the inspection of an F-35A Lightning II panel at Eglin Air Force base Fla., May 16, 2016. The Sonic 1200 displays the depth of damage inside the metal of the aircraft. Equipment like the transducers, x-rays and ultrasound machines used by NDI Airmen seek out metal fatigue unseen by the naked eye. (U.S. Air Force photo/Senior Airman Andrea Posey)