Widebodies barely feature in the top-10 most-used aircraft lists for American, Delta, and United this year. We see that the B737-800 is number-one for American, the A321ceo for Delta, and the B737-900 for United. The Embraer 175 has grown strongly for American, while the A321 has for Delta. We check out each carrier’s most-used aircraft and find out where’s best to see them.

American's top-10 aircraft this year

The Boeing B737-800 is the most-used aircraft for American, the USA's largest airline, this year. It has 10 million more seats than number-two, the A321ceo. The lack of A330, B757, B767, CRJ-200, and Embraer 190, all retired in the wake of the pandemic, is clear to see. Making it into the list for the first time is the B737 MAX 8, of which American has 41 examples, each with 172 seats. They'll increasingly replace the older sibling.

Only one widebody (the B777-200ER) makes it into the top-10, just like it did in 2019. Intriguingly, capacity by the type is down by just 4.5%, helped by strong use domestically. In July, for example, American's B777-200ERs had 70 domestic flights on one day.

1. B737-800: 53.2 million round-trip seats in 2021
2. A321ceo: 43.1 million
3. Embraer 175: 23.6 million
4. A319: 21.7 million
5. CRJ-900: 15.9 million
6. CRJ-700: 15.8 million
7. Embraer 145: 10.8 million
8. A320: 10.0 million
9. B737 MAX 8: 6.8 million
10. B777-200ER: 6.2 million

The Embraer 175 sees big growth

In third place is the 76-seat Embraer 175 (it'd be first if flights were measured). Introduced to American Eagle in 2013, the use of the larger regional jet has grown significantly in recent years. This is an example of upgauging in the drive for lower seat-mile costs, higher revenue opportunities, and stronger route performance.

Upgauging has been aided by the retirement of the 50-seat CRJ-200 in 2020 and the 44-seat Embraer 140 in May 2021. This has helped the Embraer 175 and CRJ-700, in particular, to become more dominant, as far as the scope clause limit allows.

Indeed, the Embraer 175 has a significant 13% more seats this year than pre-pandemic 2019, schedules submitted by American to OAG reveals, while the CRJ-700 is up by 4.8%. Both have overshadowed the growth of others, such as the A319 (+1.8%) and A321ceo (+1.1%).

Where are the top-10 most used aircraft?

The following table highlights American's most-used aircraft, the airports that see them the most, the number of airports and routes served, and the top route per type. It may well change. As you'd expect, RJs tend to serve more airports, hence their versatility, with the Embraer 175 used on over 550 routes.

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The carrier's two largest hubs, Dallas and Charlotte, naturally feature heavily. American's North Carolina hub is especially dominant for the CRJ-700, CRJ-900, and A320. Like the A330, the A320 was inherited from US Airways, so it is keenly used at two ex-US hubs, Charlotte and Phoenix. Elsewhere, the MAX 8 stands out, with almost all of its seats (95%) touching Miami.

The A321neo is Delta's #1 type

The 191-seat A321ceo is Delta's most-used equipment this year. Introduced just five years ago, available capacity has grown very strongly since 2019, up by one-third or 7.5 million seats. In contrast, the 180-seat B737-900ER has declined by 7%, a reduction of 2.3 million. Interestingly, Delta has more B737-900ERs than A321s, ch-aviation.com indicates.

Another key difference versus 2019 is the absence of the MD-88, which was fourth and retired 14 months ago, another consequence of the pandemic. Delta was always an important operator of it (and the MD-90).

No widebody makes the list, with the closest being the A330-300 in 12th place and the B767-300ER in 14th. Unlike the A330-300, the smaller -200 variant is Delta's least-used this year, of which it has 11. Atlanta to Salt Lake City has the most A330-200 capacity.

1. A321ceo: 30.5 million seats this year
2. B737-900ER: 28.8 million
3. CRJ-900: 18.2 million
4. B757-200: 15.8 million
5. Embraer 175: 15.1 million
6. B737-800: 13.6 million
7. A320ceo: 11.5 million
8. B717: 9.7 million
9. A319: 7.2 million
10. CRJ-200: 6.5 million

The Boeing 717 remains strong

While Delta's seats by its rear-mounted 717s have fallen by a whopping 44% since 2019, the aircraft ranks eighth this year. Following the withdrawal of Volotea’s 717s, Delta is one of only three remaining passenger users of the aircraft worldwide.

Delta opportunistically acquired the 717 from Southwest following its acquisition of AirTran. The type was superfluous to Southwest’s one fleet approach, but they were important to Delta partly because they contributed to the big reduction in 50-seaters.

Where are Delta's top-10 aircraft most used?

The 717's contribution to reducing 50-seaters, enabling Delta to reduce its fleet costs, offering more premium seats, and more, was part of a step-change approach. This saw 50-seat markets ungauged to 65-seat markets; 65-seat markets to 76-seat markets; and 76-seat markets into 110-seat markets, for instance, those operated by the rear-engine aircraft.

And while still going strong, the 717 is used on fewer routes than any other aircraft in the top-10 table. With 85% of seats, Atlanta is absolutely the aircraft's spiritual home, although around 30 routes don't touch the airline's largest hub.

United's core aircraft this year

United, the USA's fourth-largest airline in 2021, has more seats by the B737-900 (ER and non-ER combined) than any other type. The large narrowbody, of which it has 148 according to ch-aviation.com, has an average age of 20 years (non-ER) and 8.8 years (ER).

1. B737-900/-900ER: 23.0 million seats this year
2. B737-800: 22.2 million
3. Embraer 175: 19.2 million
4. CRJ-200: 12.9 million
5. A319: 10.9 million
6. A320ceo: 9.1 million
7. B737 MAX 9: 5.1 million
8. B737-700: 4.9 million
9. B787-9: 4.0 million
10. Embraer 145: 3.9 million

Where are United's leading aircraft most used?

The rise of the B737 MAX 9 into the table is hard to miss. United now has 30 examples, each with 179 seats spread across 111 in economy, 48 in economy plus, and 20 in first. It is the leading operator of the MAX 9 of airline worldwide, with more than three times the number of Panama's Copa, number-two.

Denver, United's second-largest hub this year, is very much the main airport to see the MAX 9. With almost half (47%) of all seats, over 30 destinations from the Colorado airport have or will see it at some point this year. These include the 2,405-mile link to Anchorage, served in June.

What is your favorite aircraft operated by the three airlines covered in this article? Let us know by commenting.