United Airlines, a US-based legacy carrier headquartered in Chicago, Illinois, currently maintains any airline’s largest commercial aircraft fleet worldwide. The carrier operates a fleet of more than 1,000 aircraft, many of which it fully owns, in addition to an extensive fleet of regional jets operated by airline subcontractors like SkyWest and GoJet Airlines. United’s mainline fleet consists of a mix of Airbus and Boeing jets and includes small narrowbodies like the Airbus A320 and massive intercontinental widebody jets like the Boeing 777-300ER.