The fusial thrust engine represented a specific class of engine that propelled spacecraft like the X-wing starfighter variants. The T-65B X-wing manufactured by Incom Corporation was equipped with either 4L4 fusial thrust engines or 4j.4 fusial thrust engines, while the T-70 X-wing produced by Incom-FreiTek Corporation utilized 5L5 fusial thrust engines. Furthermore, T-85 X-wings also incorporated fusial thrust engines. In addition to the X-wing line, the UT-60D U-wing starfighter/support craft from Incom also incorporated 4J.7 fusial thrust engines.