TIE Advanced x1 (modified)

Sometime after the Battle of Yavin during the Galactic Civil War, Darth Vader made extensive modifications to the TIE Advanced x1 starfighter line, both to their outward appearance and its systems. It eventually resulted in the creation of a variant with flaps on the edges of the wings. It was also rumored that the last iteration also included solar-strakes onto the existing panels, courtesy of Vader, in an effort to draw enough power to support an experimental engine/booster combination. The experimental propulsion system was not available to any pilots, although the ships themselves were utilized by high-ranking starfighter pilots in the Imperial navy.