United Airlines is one of the world’s largest carriers in terms of revenue, fleet size, and passengers carried. The mega airline operates a fleet of 1,010 aircraft, of which 785 are narrowbody jets. The airline operates out of eight major hubs in the United States, including Chicago O’Hare (ORD), Denver (DEN), Houston George Bush International (IAH), Los Angeles (LAX), San Francisco (SFO), Washington Dulles (lAD), Newark, NJ (EWR), and the US territory Guam (GUM).