United Airlines is one of the major airlines in the United States and operates an impressive fleet of 1,018 aircraft. 36 of them are the new Airbus A321neo , which has a 200-seat configuration with 123 economy, 57 premium economy, and 20 business class seats. The narrowbody aircraft are expected to operate 903 weekly flights by August this year , which is a significant increase compared to last year’s 238 flights in the same month.
The airline continues to welcome A321neos to its fleet, with 94 orders still pending and expected to be fully delivered by 2032. Additionally, United has ordered 50 Airbus A321XLRs , with the first delivery expected by January 2026, replacing the Boeing 757 . In this article, we will focus on the top 10 routes operated by the airline’s A321neos based on miles between destinations.
Data is provided by Cirium , a leading aviation analytics company. 10 Houston – Los Angeles 1,379 miles The route between Houston George Bush Intercontinental Airport (IAH) and Los Angeles International Airport (LAX) is a relatively classic connection in terms of domestic flights on the United Airlines network. Despite the flight not being significantly long, as it covers 1,379 miles, it serves a strategic purpose for the operator connecting the hub in Texas with the biggest airport on the West Coast .
The route utilizes the A321neo, which makes the trip very pleasant for the passengers. The aircraft, besides an upgraded engine and lower fuel consumption, offers a fully refreshed interior design with big backseat screens, more space for luggage, and modern noise-canceling materials. This increases comfort even on routes such as this one, which takes approximately three to three and a half hours.
Aircraft Airbus A321neo Route Los Angeles International Airport (LAX) - George Bush Intercontinental Airport (IAH) Average flights 2 Seats 300 Miles 1,379 On the route between IAH and LAX, many competitors also fly smaller narrowbody aircraft such as the Boeing 737 MAX, Airbus A320, or Airbus A319. The first use of big A321neos on the route shows that United sees this as an important strategic connection and will likely upgrade all aircraft to the high-capacity Airbus. 9 Phoenix – Chicago O’Hare 1,440 miles The connection between Phoenix Sky Harbor International Airport (PHX) and Chicago O’Hare covers around 1,440 miles and mainly serves business and leisure purposes.
Phoenix is one of the fastest-growing cities in the southwestern part of the United States, attracting many tourists, snowbirds (people who migrate from colder parts of the country), and growing technology companies. Meanwhile, Chicago maintains its status as an “economic engine” of the Midwest region. For United Airlines, this connection also plays an important role in maintaining a strong schedule between its most strategic airports, as Chicago O’Hare International Airport (ORD) is one of the airline's main hubs and its home city.
Aircraft Airbus A321neo Route Los Angeles International Airport (LAX) - George Bush Intercontinental Airport (IAH) Average flights 57 Seats 11,400 Miles 1,440 The flight takes approximately three hours and is operated by both the bigger Boeing 737 and now the new NEOs, which are growing in popularity among the operator’s fleet. An interesting nuance is that Phoenix is located in a high-temperature region. In the past, flights sometimes needed to be canceled or delayed due to aircraft performance concerns.
8 Las Vegas – Chicago O’Hare 1,515 miles The route between Harry Reid International Airport (LAS) and Chicago O’Hare International Airport is a very dynamic flight in the airline's network and the third most popular on the list. At 1,515 miles, the operator connects the two worlds of lavish and hedonistic Las Vegas with the heart of Central America, Chicago. The airline flies between the above airports multiple times a day, serving both tourists wanting to go to the capital of entertainment and having a strategic significance in connecting the city with one of its biggest hubs.
Most flights occur during the weekend; their number amounted to 72 in the previous month. Aircraft Airbus A321neo Route Harry Reid International Airport (LAS) - George Bush Intercontinental Airport (IAH) Average flights 72 Seats 14,600 Miles 1,515 It’s important to note that many of these flights are scheduled throughout the night or late evening. The so-called “red eye” flights allow passengers to maximize their journeys by allowing them to board almost any flight in Chicago in the morning.
The route is currently flown using the older 757 and the new A321neo. 7 Denver – Orlando 1,545 miles The flight covers 1,545 miles and covers half of the country, making it the seventh-longest flight in United's network. The route between Denver International Airport (DEN) and Orlando International Airport (ORD) spans mountainous central areas to coastal and sunny Florida.
Denver is a big base for many journeys from the West, and Orlando is a very popular holiday destination, so the route serves mainly holiday and leisure needs. Orlando, being home to Walt Disney World and other popular attractions, welcomes millions of visitors from the country and more, making the connection important in the network no matter the time of year. Aircraft Airbus A321neo Route Denver International Airport (DEN) - Orlando International Airport (MCO) Average flights 60 Seats 12,000 Miles 1,545 United Airlines operates many different aircraft on this route, including the Boeing 737-900ER and different aircraft from the A320 family.
The A321neo is the biggest of the three models in the fleet, and because it has the best capacity and economics, it will likely be the preferred aircraft as the deliveries are fulfilled. 6 San Francisco – Houston 1,635 miles Despite the connection between San Francisco and Houston George Bush Intercontinental Airport (IAH) being 1,635 miles, which puts it in the sixth place on our list, United has scheduled a flight between the two cities only once, using the A321neo. It connects two big cities that play a very important role in the business sense, with Silicon Valley and Texas’s capital in mind.
The flight takes around three hours and 45 minutes and is operated mainly by the narrowbody aircraft in the fleet, such as the Airbus A320 and Boeing 737 MAX 8. However, the carrier has also flown between the two cities using a big Boeing 777 making for an interesting flight. Aircraft Airbus A321neo Route San Francisco International Airport (SFO) - George Bush Intercontinental Airport (IAH) Average flights 1 Seats 200 Miles 1,635 In the past years, the operator has flown on the route using four different narrowbody aircraft,, including Boeing 737-900, Boeing MAX 9, Airbus A321neo, and Boeing 757-300.
5 Denver – Fort Lauderdale 1,703 miles The first of the top five routes on the list and one of the longer domestic flights operated by the airline. It directly competes on the route with Southwest Airlines, which also flies to the same destination. Denver is one of the primary hubs for United Airlines, making the flight a key connection with the East Coast, especially for holiday purposes.
The carrier could benefit from this major shift. The flight usually operates in the early morning or late evening and lasts around four hours. In addition to the previous route on the list, the Airbus A321neo has also flown between the destinations only once in the previous month.
With the upcoming deliveries and considerable distance, we will likely see more aircraft flying between Denver and sunny Florida. Aircraft Airbus A321neo Route Denver International Airport (DEN) - Fort Lauderdale-Hollywood International Airport (FLL) Average flights 1 Seats 200 Miles 1,703 It’s also important to note that Fort Lauderdale is a popular connection with the Caribbean, especially for those connecting from Denver, which welcomes hundreds of flights daily on the operator's network. It’s also particularly busy during winter when people want to escape from cold and snowy Colorado.
4 Chicago O’Hare – San Diego 1,723 miles This long flight connects the Middle East of the country with the sunny Californian coast. It’s a key connection that is popular among low-cost airlines. For many people living in the Chicago area, a non-stop flight to the West Coast is a great gateway, especially during the cold winter seasons.
San Diego airport is uniquely positioned between the water and the city, making for fascinating views for passengers during the approach. Flights on this route last slightly over four hours using the A320 family. The United Airlines A321neo flies between the cities two times a day.
Aircraft Airbus A321neo Route Chicago O'Hare International Airport (ORD) - San Diego International Airport (SAN) Average flights 60 Seats 12,000 Miles 1,723 Spirit Airlines also operates the route, trying to accommodate the growing demand. The A321neo is a great aircraft for this job as it balances great economy with a 200-seat capacity in three different classes. 3 Los Angeles – Chicago O’Hare 1,745 miles It is one of the busiest routes connecting the most popular West Coast destinations with United Airlines’ hometown.
Flights between the two cities are widely operated by both major airlines, like United Airlines and American Airlines , but also by smaller budget operator Spirit Airlines . On this connection, we can find most of the narrowbody plane types from the A320 family to the Boeing 737 . United flies both the A321neo and Boeing 737-900ER between the city.
Aircraft Airbus A321neo Route Los Angeles International Airport (LAX) - Chicago O'Hare International Airport (ORD) Average flights 130 Seats 26,000 Miles 1,745 In the previous month, the airline flew on the route 130 times on average using the A321neo, making it the most popular connection on this list. The traffic is considered to be varied with both business and leisure needs. The airlines see the biggest spikes in demand during holiday seasons.
2 Boston – Denver 1,754 miles The route connects the northeast with the Rocky Mountains and covers 1,754 miles. Besides United, the route is operated by Southwest Airlines , Delta Air Lines , and JetBlue , using the small Airbus A220 . United uses both its Boeing 737 and A321neo fleets, flying between destinations multiple times a day.
The flights take up to four and a half hours and usually take place in the morning or evening. Aircraft Airbus A321neo Route Boston Logan International Airport (BOS) - Denver International Airport (DEN) Average flights 30 Seats 6,000 Miles 1,754 Flights between Boston and Denver have an interesting dynamic. Throughout the week, elegant business people are not difficult to spot, and during the weekend, we see more families and holiday travelers.
The route is also a great example of the importance of routes in the country that connect important cities. 1 Chicago – San Francisco 1,846 miles Finally, the last is between Chicago O’Hare and San Francisco, which measures 1,846 miles. This makes it the longest connection on the list operated by United’s A321neo.
This flight connects two of the airline's biggest hubs, making it an important strategic route. It welcomes many people connecting on the network as well as business people needing to travel between cities. Only last month, it flowed 115 times on average by the model, making it the second most popular on the list.
Aircraft Airbus A321neo Route Chicago O'Hare International Airport (ORD) - San Francisco International Airport (SFO) Average flights 115 Seats 23,000 Miles 1,846 Despite United dominating the route, American Airlines and Alaska Airlines also fly it. United utilizes many models in its fleet to get across cities, including A321neos, 737-9 MAX, 757-300, and even the mighty 777-200. What are the longest routes operated by United Airlines' Embraer E175s from Denver International Airport?.
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United Airlines' 10 Longest Airbus A321neo Routes

Some of the routes are also flown by the carrier's other popular narrowbody aircraft.