The City of Chicago is taking gates at O’Hare away from American Airlines, and giving more gates to the dominant airline at the airport United. American Airlines sued to stop this, saying it violates the airport use agreement that the airlines have signed.

• The city has a formula to reallocate gates based on historical flying
  
• But the 2018 use agreement is pretty clear that this isn’t supposed to happen yet
  
• And giving more gates to United helps them fly more and get more gates in the future, while limiting American’s flying and penalizing them further in the future

American wasn’t able to get a temporary restraining order in federal court to stop this process. They voluntarily dismissed the federal claim last week and re-filed in Cook County Chancery Court (American Airlines, Inc. v. The City of Chicago and United Airlines, Inc. case number 2025CH07402). The case has been assigned to Judge Thaddeus L. Wilson.

Here’s why the move makes sense:

• American failed to receive its temporary restraining order in federal court. (Update: American emphasizes that they did not receive an adverse ruling on the restraining order.)
  
• United was allowed to intervene in the case already. After all, the results of the case determine how many gates they’ll have and their interests (in theory!) aren’t the same as the City of Chicago’s.
  
• Purely equitable claims in the Chancery court are generally bench-tried as I understand it, so American doesn’t risk a hostile jury preferring locally-headquartered United. United had demanded a jury trial.
  
• The Chancery court isn’t subject to Seventh Circuit precedent requiring a public interest balancing test.
  
• And this court is generally regarded as more willing to maintain status quo pending trial.

According to American Airlines,

American continues to vigorously pursue its rights in accordance with the 2018 lease agreement to ensure the airline will sustain a competitive presence at O’Hare Airport well into the future.

The lawsuit stems from a 2018 truce after United and the city agreed to a plan that would give the hometown carrier room to grow at the expense of American. United and American signed a 15-year lease that supported terminal redevelopment and paused any shift in “preferential” gates until a Gate Space Ramp‑up Period had run its course.

American says the clock on that period did not begin until the last three “L‑Stinger” gates in Terminal 3 opened on March 14, 2025 – so redetermination can’t start before April 2027.

They allege that the city is helping United in its plan to squeeze American out. And it probably is! United is based in Chicago and there’s a huge political push behind keeping them from moving their headquarters to Denver.

United is set to gain six gates while American gives up most of Concourse G (up to nine regional jet spots) and receives back the three just‑opened L concourse stinger gates. That could mean a loss of as many as six gates (four for larger planes).

United Airlines, Chicago O’Hare

American’s arguments over the 2018 Airline Use and Lease Agreement:

• § 5.3.2 says the City “shall not initiate the next annual redetermination of Gate Space until April 1 of the year following the end of the Gate‑Space Ramp‑up Period,” which itself cannot start until gate assignments match Exhibit D‑1.3 and stay in place for 12 months (§ 5.2.4). Exhibit D‑1.3 includes three new L‑Stinger gates in Terminal 3.

• The last L stinger gate opened March 14, 2025, so the ramp‑up ends March 14, 2026 and any redetermination can’t be started before April 1, 2027. Chicago began this – using 2024 data – in February 2025.

American Airlines Chicago O’Hare

American’s case is fairly solid that:

1. the redetermination of gates starts a year after the ramp up period,
   
2. That doesn’t start until the 3 L Stinger gates come online – this is shown clearly in the exhibits, and the City’s chief negotiator confirmed this in writing.

Chicago O’Hare

The city will argue that the ramp‑up when two of the three gates opened, and the 12‑month clock has already finished – and that the document refers only to Delta’s relocation into terminal 5, not the L‑Stinger gates. And they’ll argue that their fingers were crossed when they clarified that the ramp up period includes those L gates (more technically, that email assurances can’t supplement the meaning of the document).

American Airlines Boeing 787-8 at Chicago O’Hare

And in federal court they were in a position to argue that re-allocating underutilized gates benefits passengers, American is ramping up its flight at O’Hare to use these gates and benefit to passengers comes from greater competition not handing gates to United.

Specifically against an injunction the city can argue that any damages should be in the form of a monetary judgment (i.e., they’re compensable) rather than injunctive relief.

American is on pretty solid ground here but they need an injunction not just a final win in court, and United and the city have hometown court advantage, in a jurisdiction where that matters.

(HT: Enilria)

Update: an American Airlines spokesperson shares,

Fueled by its long-standing commitment to Chicago, American continues to vigorously pursue its rights in accordance with the 2018 lease agreement to ensure the airline will sustain a competitive presence at O’Hare Airport well into the future. That competition, unique to the only dual-hub airport in the nation, is inherently beneficial for customers as it yields lower fares and more extensive flight schedules for Chicagoland travelers.

The airline’s recent expansion at ORD — evidenced by 22 new destinations in 2025 — reinforces its focus on the local customers, team members, businesses and communities that benefit from robust air service that bolsters the economy and keeps Chicago on the map for tourism and business development.