Sorry for the delay on this one, but it’s now time for the final chapter in the “look back” series. If you missed the look back at American and Delta, be sure to check those out. Now let’s look at United.

The most remarkable story here is the dramatic decrease in smaller jets. Back in 2000, nearly 40 percent of the combined United and Continental fleet was under 140 seats. (Yes, Continental numbers are included from before the merger.) Now it’s less than 15 percent. (All fleet counts are for the end of the year shown.)

The real story isn’t entirely clear here however, because you actually had two very different airlines. United stood still and ordered nothing for years and years while Continental had new airplanes coming in all the time. Let’s look at that in more detail.

Aircraft With Fewer Than 118 Seats

Let’s start at the bottom and work our way up.

I know, the first question is… why is the cutoff 118 seats when it was 120 elsewhere? Well, United’s 737-700s are not dense and have only 118 seats on them. Still, that size airplane belongs in a different class than this, so I drew the line at 118.

Even with the retirement of the 737-200s, there was still a large 737-500 fleet at both carriers. I’m actually surprised how many were still there until even as late as 2005. Retirements accelerated after that. These airplanes survived the merger, but not much longer. And now they’re all gone from the fleet.

The Next Generation: Nothing. United was looking closely at the C-Series and Embraer aircraft until Boeing swooped in and gave it a killer deal on 737-700s. So it isn’t interested in this space at this point.

Aircraft With 118 to 140 Seats

Next stop, more massive declines.

Once the 737-300 was retired, Continental’s 737-700s and United’s A319s carried the torch. The fleet of A319s had been stagnant for years while the 737-700 fleet grew modestly. Now both are growing. United has places two separate orders for a total of 65 737-700s. It’s also picking up cheap used A319s on the open market. This should help to pull flying away from regionals further.

The Next Generation: Nothing again. United may have more current generation 737-700s on order and it’s picking up used A319s as well, but it has nothing in the next generation in this size on the books.

Aircraft With 140 to 160 Seats

Finally, a more steady fleet size.

Once older types were retired after 2000, United settled on the A320 and again, remained stagnant there for years. Continental, of course, went with the 737-800 and grew that fleet until it realized it wanted something even bigger.

The Next Generation: Once again, nothing. It seems amazing, but United really has focused on bigger airplanes, as you’ll see in a moment. There’s just been no movement in this category.

Aircraft With 175 to 200 Seats

Now we get to what United considers its sweet spot in the narrowbody world.

Look at the growth! Sure, the 757 fleet has shrunk. In fact, I believe the last of the pre-merger United 757s are gone or about to be gone, with the exception of the p.s. fleet. The remaining 757s are for transcon and East Coast-Europe flights. In their places, the 737-900s have become the backbone of the fleet.

Note that the international 767-300ER falls into this category as well, even though it’s used for very different missions. United may be the only airline that still has First and Business Class on its 767s, so it is shockingly light on seats. But that’s changing. The 767s have been in United’s fleet for ages, but these international aircraft will be refitted with Business… er, Polaris, and no First Class eventually. I would imagine this airplane will have more than 200 seats whenever that happens.

The Next Generation: It’s most definitely going to be the 737 MAX 9. United already has 100 on order. On the widebody side, there’s nothing this small, and that’s smart.

Aircraft With 200 to 240 Seats

Now let’s talk about the rest of the widebodies.

Yes there’s a straggler here, and as with Delta, it’s the 757-300. That airplane came from Continental and continues to serve a niche in medium-haul markets with high demand. But it’s not growing at all.

The 767 fleet will grow. Well, actually, it won’t grow but those airplanes with fewer than 200 seats will be refit to be in this category. (The current 767s in this group used to be domestic aircraft with more density, but they have been refitted.) It won’t be much growth.

Where’s the growth? Well, a little is with the 787-8, but United has no more on order at this point. Presumably it might be able to benefit from more at some point, but it’s focusing on bigger airplanes.

The Next Generation: United was an early bird with the 787s, so I guess the next generation is now. But the 787-8s are fully delivered and it’s unclear what, if anything, will replace the 767-300s in time.

Aircraft With 240 to 260 Seats

The bigger widebodies are where things get interesting.

Like Northwest, Continental relied heavily on its DC-10 fleet for international service. United, however focused it more on domestic operations. Once that was gone, United never replaced the airplane. Continental, however, used 767-400s (and larger 777s). United eventually took delivery of some 787-9s.

It looks like this fleet has been fairly static, but that’s really not the case. Those 767-300s were in a higher-density domestic configuration for, well, domestic flying. Those have now been converted to international aircraft as you saw in the last grouping. So while the amount of domestic capacity in this size range has shrunk to nothing, the international fleet in this size range has grown, and there’s more coming.

The Next Generation: As with the previous one, the 787 is the next generation. At this point, United still has a few more of those on order, but it’ll be awhile before the 767-400 needs to be replaced.

Aircraft With 270 to 300 Seats

Let’s keep on moving up the ladder.

I guess I didn’t really need a graph here. United and Continental have both relied on the 777 for years. While United ordered 777s very early, it then stopped. Continental kept taking delivery well beyond United, but there’s nothing left on the books at this point.

The Next Generation: This is interesting since United has gone with the 787-10 here. It has 14 on order and presumably if that airplane performs as expected, it could end up replacing the smaller 777-200s in the long run. But that’s still an open question.

Aircraft With More Than 300 Seats

And now, to close this out.

This is another split operation. Domestically, United has for years had its shorter range 777-200s flying domestically, often between hubs and to Hawai‘i (and eventually into Micronesia after the merger). The new United likes this plan and it bringing another 10 into the domestic operation going forward.

Internationally, it’s all about the 747, and that airplane is going out in the next few years. So what will replace it? Well for now, it’s the 777-300ER. United has 10 of these coming on the property. After that? Well, there’s a plan for that too.

The Next Generation: Though United has the 777-300ER coming soon, it also has an order for 35 of the A350-1000 aircraft. There isn’t a domestic replacement for the high-density 777-200 at this point, but I’m not convinced United would need one for a long time, if ever.