Astromechs

" An astromech droid, also referred to as an astro droid, was a type of droid that served as an automated mechanic, performing a variety of repair duties and often serving as an adjunct or substitute for a nav computer on smaller starships. Astromech droids could also use the mainframes of larger ships to their advantage. Many starfighters relied on astromech copilots. "

Only X-Wings, E-Wings and Y-Wings can be upgraded with an Astromech.

Astromechs