From Wikipedia "X-wings are fictional starfighters from the original Star Wars trilogy and the Star Wars Expanded Universe. They are depicted as the primary interceptor and dogfighter of the Rebel Alliance and the New Republic. The craft has been merchandised as a variety of toys and models and licensed for use in games, novels and comics.
Industrial Light & Magic's (ILM) Joe Johnston sketched and Colin Cantwell built models that eventually became the final X-wing fighter in Star Wars Episode IV: A New Hope. The X-wings were designed to appear more "traditional" than the Empire's TIE fighters. ILM built miniatures in various scales, with wing markings indicating which prop represented which pilot. When ILM fell behind on generating X-wing footage, Star Wars producer George Lucas and his editors temporarily used World War II dogfight footage for initial editing cuts. Each X-wing model was built around a hollow core made from surgical tubing, which allowed lighting, cooling, and electrical connectors for the wing motors to be installed and maintained. The cockpit windows were made from faceted glass so that accurate reflections could be filmed. Although the movie's initial script and novelization describe the X-wings as belonging to "Blue squadron", limitations in bluescreen photography led to the markings on the filming models, as well as the fictional squadron affiliation being changed to red.
In addition to miniatures, the production crew made a single, full-size X-wing for scenes in the Rebels' Yavin IV base hangar; combined with cardboard cutouts and careful editing, the Rebels appear to have dozens of fighters. The production crew also made a full-size X-wing cockpit that was used for all actors; the astromech droid visible behind each actor was changed for each starfighter. Background noise pitch and tone also varied between X-wings to further differentiate the characters piloting them.
The "lake" in which Luke Skywalker (Mark Hamill) crashes his X-wing in Star Wars Episode V: The Empire Strikes Back was only 3.5 feet (1.1 m) deep, requiring the creation of a rig resembling the starfighter sitting in the lake at an angle. The rig was built in hinged sections so it could be manipulated by frogmen to sink or rise, a key feature for the scene when Luke fails to levitate his ship from the water.In 1993, ILM visual effects specialist John Knoll created a proof of concept test of dogfighting X-wings and TIE fighters to demonstrate the feasibility of using commercially-available desktop computer software for simple animation work. This resulted in numerous parts of space battle scenes being "re-shot" as digital animations for original trilogy's Special Edition releases. The ARC-170 starfighter seen in Star Wars Episode III: Revenge of the Sith is deliberately reminiscent of the X-wing's design.