The TIE Advanced x1, alternatively known as the TIE/ad, represented an advanced starfighter prototype. This model was a part of the TIE fighter series line, produced by Sienar Fleet Systems. Notably, Darth Vader piloted a TIE Advanced x1 himself.
Sienar Fleet Systems heavily referenced designs from Kuat Systems Engineering ships when designing the starfighters in its TIE fighter series, such as the V-wing and the Eta-2 interceptor. Sienar also experimented with cutting-edge models that had localized improvements and secret technological advancements. One such model was the TIE Advanced v1 prototype, which was based on Sienar's Scimitar Star Courier. This prototype eventually led to the TIE Advanced x1, which included both a hyperdrive and a deflector shield generator. Darth Vader himself flew a modified early prototype from the Advanced x1 line. Vader's version had enhanced speed and greater firepower, with fixed twin blaster cannons and a cluster missile launcher.
An experimental shield system protected the x1. A supermagnet at the ship's rear projected a stabilizing field. Projector bars (forward and lateral pairs) deployed deflector energies. These experimental shield systems sometimes needed last-minute adjustments, often performed personally by Vader. Vader requested a custom cockpit to fit his armored suit, and the fighter's curved wings contained high-performance solar cells. The ship was also capable of operating in water.
By 4 BBY, the Sith Lord Darth Vader owned and operated an experimental modified early prototype of the TIE Advanced x1. He piloted it into a rebel fleet, leading a daring attack that destroyed the rebels' flagship, the Phoenix Home. Later, he used it to travel to Malachor to battle his former Padawan, Ahsoka Tano.
During the Battle of Yavin in 0 BBY, Vader again flew his TIE Advanced x1 to chase and eliminate Rebel fighters that were attacking the first Death Star. He shot down several starfighters until a TIE/ln space superiority starfighter collided with his fighter during a surprise attack by the Millennium Falcon, unexpectedly taking him out of the fight. After the collision, Vader lost control and spun into space, thus avoiding the Death Star's destruction. The ship was disabled and left adrift in the battle station's debris. However, Ciena Ree and Berisse Sai, piloting a Gozanti-class cruiser, later picked up Vader and his ship.
Although production was limited, the TIE Advanced became a favorite among elite units. One Ace from Storm Squadron piloted a TIE Advanced. Other Aces from different squadrons also flew the TIE Advanced, making it a favorite among them. Maarek Stele once flew a TIE Advanced, as did others like Juno Eclipse. Following the Battle of Yavin, the Alliance to Restore the Republic acquired stolen versions of the craft and gave them to Saponza's Gang. Vader also continued to fly his TIE Advanced. A TIE series craft, with wings similar to the Advanced x1 but lacking the rear design, was part of Commander Ellian Zahra's Hunter Fleet following the Battle of Hoth. This fighter participated in the battle at Elessia.
On the Core Worlds planet of Bar'leth, at least two TIE Advanced x1s were placed on hoverpads as part of an Imperial Military parade for Empire Day. This event showcased new prototypes and officially deployed military equipment in a galaxy-wide broadcast. However, the Rebel Alliance Navy capitalized on the broadcast by targeting and eliminating the parade forces. They ensured no civilians were harmed but demonstrated to the galaxy that they still posed a threat to the Empire, despite the Battle of Hoth.