Traditionally, legacy carriers in the United States establish large hub facilities in select markets. American Airlines and United Airlines follow this pattern with their dedicated hubs across the country, typically avoiding overlap to minimize competition. When airlines operate hubs near each other, it often prevents either from dominating the market.
Chicago O'Hare International Airport (ORD) is a notable example where American Airlines and United Airlines compete directly. Recently, American Airlines filed a lawsuit against the city of Chicago over alleged uncompetitive gate redistribution practices. United Airlines has also been assertive in its tactics.
American Airlines argues that maintaining an agreed-upon gate-assignment timetable benefits passengers by preserving competitive dynamics at the airport. The 2018 agreement signed by both airlines and the airport prohibits gate reallocation until March 2026. Offering more slots to United could give it an unfair advantage, according to American.