The BTL-S3B Y-wing starfighter was a variant of the twin engined BTL-S3 Y-wing starfighter produced by Koensayr Manufacturing as part of the BTL line. Like the S3, the S3B was a shielded two seater assault starfighter manned by a pilot and gunner. The S3B had twin blasters in place of the ion cannon the S3 used for its turret, and was more successful than the BTL-A4 Y-wing variant.