Just like the entire Valley of the Sun, Phoenix Sky Harbor International Airport started off sleepy but has grown dramatically in recent decades. Now, the airport is getting one step closer to its most ambitious expansion project yet with a new west terminal, and American has just been named as the “primary carrier.”

This is a big deal, but I thought a little history lesson would be useful to see just how this airport has evolved over the years, because it has changed a lot. So, let’s get going.

The name Sky Harbor has to be the best airport name around. (You had your chance, Port Columbus, but then you renamed yourself.) But while the name is great, the terminal numbering has generally confused people. For decades, there has been no Terminal 1, and that left many wondering if it ever existed. It did indeed. What would become Terminal 1 was the first modern terminal at the airport. It opened in 1952.

This little slice of terminal was accessed from the west, and it was the only terminal for a full decade until the jet-age Terminal 2 opened up. At the time, the original terminal became the West Wing while the new terminal became the East Wing. It has now been replaced with a ballroom. (Too soon?)

This remained the configuration for some time, and traffic continued to enter from the west with all terminals being south of the main roadway. Parking was to the north. But then, it was time to keep building to the east, and a realignment happened. T3 was born in 1979, and that’s when the terminal numbering went into place with the West Wing becoming T1 and the East Wing becoming T2.

T3 had concourses on both the north and south sides of the terminal building itself. There were roadways on both sides of that building, and this made for quite a mess integrating with the original roadway system. You can still see some of that mess today when coming in from the west.

T3 opened at the dawn of deregulation, and that meant it was time for pure chaos in Phoenix. Bonanza was the hometown airline once it moved its headquarters to town in 1966. That carried on through the mergers to form Air West, Hughes Air West, and eventually Republic. Phoenix was also a key stop on southern transcontinental routes for airlines like TWA and American. But those would all fall by the wayside soon enough.

Southwest came to the airport on January 31, 1982, and it grew fast. Then the new hometown airline America West started flying on August 1, 1983, and it grew even faster. By 1985, Republic had given up, and America West became the airport’s largest airline by far.

Even with Republic shrinking, the airport saw explosive growth in departures, according to SkyGo schedule data from OAG. In 1981, the airport had fewer than 70,000 departures. In 1985, that was over 120,000. Even with the brand-new Terminal 3, the airport was bursting at the seams.

Southwest had taken over Terminal 1, and it was so overcrowded that the airline was parking airplanes on every spare piece of ramp it could find. Meanwhile, America West was in Terminal 3’s south concourse. That airline grew so fast, a whole new temporary concourse had to be added on just to the west.

This wasn’t sustainable as growth was expected to continue in Phoenix, so planning for Terminal 4 kicked off. This massive new terminal sat to the east of the existing terminals, and it would have room for up to eight concourses. To start, only four would be built.

When it opened in late 1990, America West moved in to the two north concourses (called N2/3 but in practice being the low-A and low-B gates) while Southwest moved into the two southern concourses, S3/4 (the low- and high-C gates). This allowed PHX to shut down Terminal 1, and those temporary south concourse gates in Terminal 3. They would both be demolished shortly after, but the numbering didn’t change. The terminals stayed as 2, 3, and 4.

In 1994, the N4 concourse (high-B) opened as the international gates. N1 (high-A) followed in 1998, and S2 (low-D) opened in 2004, leaving the airport looking somewhat different but still having some room for growth just in time for the America West/US Airways merger.

That merger didn’t bring growth, and the airport’s terminal situation stayed the same for a long stretch. In 2013, the Sky Train opened connecting T4 with economy parking to the east and the light rail station. That was extended to T3 in 2014, but it didn’t get completed all the way to the rental car center in the west until 2022.

The train never stopped at T2, because T2 was not long for this world. In 2016, Phoenix kicked off a massive renovation of T3, which included creating a single security checkpoint and demolishing the south concourse. In its place, a new concourse would be built that was positioned east-west instead of north-south.

This project finished in January 2020, and the airlines moved out of T2 shortly after. T2 was shut and demolished the next year.

What you see above is the current state of the airport with only two terminals that are still numbered 3 and 4. The terminals are almost fully built out with no more room to grow to the east after the new concourse on the northeast side of Terminal 3 opens in 2027.

Here’s how the airlines are divvied up today with the new concourse on the map as well.

For years, Phoenix has talked about what will be built to the west of the existing Terminal 3. All of that space is wide open for redevelopment, and it will be the site of the new west terminal. In general, we’re going to see this terminal built in this area bounded by Terminal 3 on the east and a new taxiway U on the west which will connect the south and north runway complexes:

We don’t know much about this terminal except that it’s coming. And the release this week says American will be the primary carrier, which means T4 is about to have a whole lot more room.

That’s a bit forward. T4 will have a lot of room eventually, whenever this is built. Right now, the plan is to have the new facility open by 2033.

We don’t know how big it will be or how much will be built in any first phase. We don’t even know what it will look like. But we do know there are renderings which suggest when fully built out, it will be able to rival T4 in size.

^{West-facing rendering via City of Phoenix}

Don’t put much stock in that rendering. Just know that the terminal is coming, American is committed, and Phoenix is preparing to have a whole lot more terminal space in the years ahead.

Now if the city could just find some more water…