Onyx Squadron, a starfighter squadron serving the Galactic Empire, found itself under the command of Onyx Leader [Ubbel]. Within its ranks in 10 BBY were Cadet Lyttan Dree and Cadet Han Solo, both piloting the formidable TIE/rb heavy starfighters. During one mission aboard a Cantwell-class Arrestor Cruiser, the squadron faced an assault from raiders. Solo, in an act of defiance, ignored direct commands in order to rescue Onyx Two, which resulted in his own ship being damaged and subsequently crashing onto their own vessel. His actions then led to his sentencing at a tribunal for insubordination.