Last week, Airbus (EADSY 0.93%) announced that it will wind down production of its A380 jumbo jet by 2021, confirming recent media reports. Airbus' vision of rising airport congestion forcing airlines to adopt ever larger airplanes was undermined by the growing popularity of small widebodies, such as Boeing's (BA -1.53%) 787 Dreamliner, which have enabled airlines to operate more point-to-point routes that bypass the most congested hubs.

That said, there is still a market for large widebody aircraft -- particularly if they can offer a unit cost advantage over their smaller brethren. Boeing's new 777X aircraft family is set to dominate this market in the coming years, capitalizing on the failure of Airbus' A380.

An overlapping customer base

The Boeing 777X is an updated version of Boeing's highly successful 777 aircraft family that will enter service next year. It promises to offer additional range and better fuel efficiency, thanks to a new wing and state-of-the-art engines. The smaller 777-8 model is roughly similar in size to the current 777-300ER model, as well as Airbus' competing A350-1000. Meanwhile, the larger and more popular 777-9 version is the largest twin-engine plane on the market and has no direct competitors.

Like the A380, the 777-9 will enable airlines to expand at congested airports where it's not practical to add lots of new flights. But the 777-9 should have significantly lower unit costs than the A380, while also being easier to fill, on account of being smaller.

Check out the latest Boeing earnings call transcript.

A rendering of a Boeing 777-9 flying over clouds

Boeing expects the 777-9 to have industry-leading unit cost performance. Image source; Boeing.

Given that the two planes are designed to perform similar missions, it's not surprising that there is a huge amount of customer overlap between the A380 and 777X. Of the roughly 250 A380s that Airbus will ultimately deliver, Emirates will have taken 123. Its two regional rivals -- Qatar Airways and Etihad Airways -- along with Singapore Airlines and Lufthansa together account for another 58 deliveries.

These same five airlines account for 275 of the 326 firm orders in Boeing's 777X backlog. As with the A380, Emirates is the dominant customer for the 777X, with 150 firm orders.

Unsteady demand for the 777X

While demand for A380s has fallen off a cliff in recent years, the 777X hasn't been much more popular. The proliferation of low-cost long-haul airlines has held down fares for international travel, making most airlines wary of committing to ambitious growth plans. As a result, Boeing has received only one significant order for the 777X since the beginning of 2015: a 20-plane deal with Singapore Airlines signed two years ago.

Meanwhile, falling oil prices, cutthroat competition for connecting traffic, and pockets of weakness in the global economy have pressured results at Emirates, Qatar Airways, and Etihad in recent years. This situation has made it clear that they need to radically scale back their ambitious growth plan, calling into question whether they need as many 777Xs as they have ordered.

The death of the A380 is a huge tailwind

Fortunately for Boeing, the end of A380 production could lead to a wave of 777X orders in the coming years. Emirates is already contemplating ordering at least 20 more 777Xs, according to Bloomberg, despite having 150 on order.

Emirates doesn't need to grow at a breakneck pace to justify an expanded 777X order book. The carrier currently has about 250 777-300ERs and A380s in its fleet, and the 777X is likely to be the airline's main replacement for both models. Emirates tends to retire its planes at a younger age than most airlines, so it will probably replace the vast majority of its current fleet by 2030.

An Emirates A380 jet on the ground.

Image source: Emirates.

Similarly, Singapore Airlines has already retired its oldest A380s, and Qatar Airways recently confirmed that it only expects to keep its A380s for a total of 10 years. As more airlines retire their A380s, maintenance costs are likely to rise, encouraging other major operators like Qantas to follow suit.

Boeing could still see some 777X order cancellations by Etihad Airways, which is dramatically restructuring its business. But on the flip side, it has a legitimate shot at snaring new orders from Qantas, Turkish Airlines, and some of the big airlines in East Asia.

In recent years, airlines have shown a clear preference for the smaller Boeing 787 and A350 families over the largest widebody jets. Nevertheless, with the A380 out of the picture, Boeing's 777X should be able to carve out a profitable niche for itself.