After last October’s gate reallocation, the battle lines were drawn at Chicago’s O’Hare airport. United had control of Terminal 1 already and had wrested full control of Terminal 2 away from other airlines (the one exception being its close partner Air Canada having a gate). American continued to have its hub in Terminal 3, but it lost ground, nearly exiting its old stomping ground on Concourse G entirely. But now, it’s time to talk reallocation once again, and American will regain territory on Concourse G. This year is poised to be even more complex, and I blame Spirit.

Let’s take a look at the battle map.

Oh wait, that’s not it. Hold on. Here is the map since last October:

The current status quo shows United and American controlling the vast majority of gates in the central terminal complex. (Delta and Southwest out in Terminal 5 are pretty much irrelevant to this discussion.) The only outliers other than that one Air Canada gate were all on Concourse G.

Spirit had four gates on G while Alaska controlled one. Seven were common use, and one was unassigned. That left American with just two gates on G, those closest to H. But now, things are changing again.

It started late last year when Spirit took $30 million from American to assign two of its gates, G8 and G10, to American. Then, just recently, it got United to pay $30.2 million for its other two gates, G12 and G14. From now on, Spirit will use common use gates for its operation… as long as it still has one (an operation, I mean).

But all of this is fleeting, isn’t it? After all, February kicks off the next reallocation season which will culminate in the next shifting of gates going into effect in October. But what will happen? I am not completely sure.

We do know that American’s surging operation last year means it will gain some gates. Remember, United picked up six gates last year, but they didn’t get assigned until October 1. So for nine months that lead to this year’s allocation, United was operating off fewer gates while American was ramping up quickly. United will lose something. There could be some shuffling with Delta or other little guys too, but again, nobody cares about Terminal 5.

So the question again becomes… how many gates will each airline gain or lose? This is where things get nutty. I asked the City of Chicago exactly how this works with Spirit giving up its gates. Will Spirit’s utilization at each gate contribute to American’s and United’s numbers? Despite some people at airlines saying they thought this would work this way, that is not the case. The Chicago Department of Aviation’s Director of Communications Kevin Bargnes explained that except for a couple of exceptions which don’t apply here:

Primarily, the only thing that matters when gate frontage is reallocated at O’Hare International Airport is how many scheduled departures each airline operates during the calendar year. It doesn’t matter which specific gates those flights use. It also doesn’t matter whether those flights depart from the airline’s own preferential gates, common-use gates, or another airline’s preferential gates

Alright, so we just take total departures and look at percentages for those airlines. I guess Spirit’s goal is to keep having the right to 4 gates so that American and United can keep using them. So let’s look at some numbers.

The way I calculate it, American’s share of departures in calendar year 2025 has now climbed about a point to 39.5 percent while United’s has fallen about a point to near 51.5 percent. Playing with the numbers, this looks like American should gain about 3 gates while United would lose the same amount. At the same time, Spirit does look to be underutilizing its gates the most with Delta and Southwest to a lesser extent.

So does that mean Spirit will lose gates? If so, what does that mean for American and United? I’m sure it’s buried in their contracts with each other, though I did see something in a United memo that caught my eye. United says one of the Spirit gates will go back to the city for reallocation this year. I take that to mean that United paid $15.1 million to effectively prevent itself from having to lose one of the gates it has today that it expected would leave. My head is spinning trying to figure this out.

My assumption here is that with the purchase of Spirit gates on G, United will probably have enough gates there to give most back and not have the rest of the footprint impacted. Meanwhile, American will gain more back on G. The wildcard in this is we don’t know how many common-use gates the city needs next year.

We’ll know for sure once June rolls around, and in this case, I’m so unsure of the situation that I will be eagerly awaiting that June date. The battle for Chicago rolls on.