The BTL-S3 Y-wing starfighter was a variant configuration of the BTL Y-wing starfighter. It was used primarily by the Alliance of Nations
The BTL-S3 was the most common Y-wing configuration. A two-man strike starfighter, the first crew member piloted the craft, while the second acted as a gunner and controlled the two swivel-mounted ion cannons, located right on top of the cockpit.
Many Y-wings of this variant were modified with defensive rapid-fire blaster turrets replacing the ion cannon turret, and particle cannons instead of the dual laser cannons on the nose. These Y-wings were used as heavy capital ship destroyers, and were eventually phased out by the new B-wing starfighters.