El Salvadoran Air Force Tech. Sgt. Moisés Rolando Serrano Borjorquez, aviation electrician, looks through the viewer of a night vision goggle test set during a Subject Matter Expert Exchange at Davis-Monthan Air Force Base, Ariz., March 7, 2018. Air crew flight equipment airmen are responsible for ensuring that all air crew flight and safety equipment is operating properly. They maintain equipment items like night vision goggles, flight helmets and oxygen masks and pack emergency items like parachutes and survival kits. (U.S. Air Force photo by Staff Sgt. Angela Ruiz)