U.S. Air Force Senior Airman Hector Chacon, a nondestructive inspection journeyman with the 31st Maintenance Squadron, use an oil analysis unit to test the engine oil from an F-16 Fighting Falcon aircraft April 9, 2014, at Campia Turzii, Romania, during exercise Dacian Viper 2014. Dacian Viper is a bilateral air exercise designed to enhance interoperability and readiness between the U.S. Air Force and the Romanian air force.