The Airlines With The Largest Narrowbody Only Fleets

Which of the world’s airlines operate the largest narrowbody-only fleets? Simple Flying recently explored the world of widebody-only carriers, so now seems as apt a time as ever to ask the same question for airlines that exclusively fly single-aisle aircraft. As we will see, the theme of low-cost carriers with uniform fleet structures is key to this question.

Southwest Airlines flies 737 aircraft from the Boeing 737 family. Photo: Vincenzo Pace | Simple Flying

Southwest Airlines

When Simple Flying explored the world’s largest airline fleets of any structure back in March 2021, most of the top 10 had both narrowbody and widebody designs. However, Southwest Airlines’ all-narrowbody fleet is so extensive that it was able to break into the top 10. Indeed, the Dallas-based low-cost carrier placed fourth at the time of writing.

Data from shows that all of Southwest’s aircraft belong to Boeing’s popular 737 family. In an incredible coincidence, its fleet presently consists of exactly 737 aircraft! Of these, the most dominant variant is the 737-700. Southwest operates a staggering 462 of these twinjets, of which 405 are active. They have an average age of 17 years old.

Southwest also operates a three-figure contingent of the larger 737-800, totaling 207 examples. Of these, all but three are presently active. They are much younger than their 737-700 counterparts, and they clock in at an average age of just 6.1 years old.

Southwest B737 MAX
The 737 MAX series will help modernize Southwest’s fleet. Photo: Vincenzo Pace | Simple Flying

Southwest’s other 68 aircraft are examples of the Boeing 737 MAX 8. Of these, just two are presently inactive. These twinjets have an average age of just 2.6 years old. Going forward, Southwest has a further 132 MAX 8s on order, as well as 234 MAX 7s. These will see the carrier’s fleet undergo widespread modernization in years to come.

SkyWest Airlines

Staying in the US, Skywest Airlines is another carrier whose extensive single-aisle fleet saw it place in the world’s top 10 largest fleets as a whole. This regional carrier came in seventh, and its fleet is dominated by single-aisle regional jets. In total, it flies 567 aircraft.

What is important to understand about this carrier is that its aircraft don’t typically bear a SkyWest livery. Instead, they operate feeder services on behalf of US mainline carriers under brands such as American Eagle, Delta Connection, and United Express.

Delta Skywest CRJ200
SkyWest’s most numerous aircraft type is the Bombardier CRJ200. Photo: Eric Salard via Flickr

The most common of the 567 aircraft in SkyWest’s fleet is also the smallest, namely the Bombardier CRJ200ER/LR. It operates 196 of these 50-seaters, of which 145 are presently active. They are 19.1 years old on average. Another common type is the 76-seat Embraer 175LR, of which it operates 154 examples (150 active). These are 5.1 years old on average.

Staying with Embraer, Skywest flies 44 standard E175s, all of which are active. These are among its youngest aircraft, clocking in at an average of just 2.2 years old. The rest of SkyWest’s aircraft are mid-size to large Bombardier CRJ variants. 129 of these are versions of the CRJ700 (97 active), while the remainder are 44 larger CRJ900LRs (41 active).


Irish low-cost carrier Ryanair was the third and final all-narrowbody operator to make it into the top 10 largest airlines back in March 2021. It placed eighth, and, across the whole, Ryanair Group, it has a grand total of 460 narrowbody twinjet aircraft at its disposal.

Ryanair Boeing 737-800
Ryanair’s 737s have become a common sight across Europe. Photo: Getty Images

Most of these aircraft are examples of Boeing’s 737-800 twinjet. This design accounts for 417 planes in the Ryanair Group’s collective fleet, representing a proportion of more than 90%. Of these, Ryanair itself flies 251 examples, whereas the remaining 166 are operated by its group partners Buzz and Malta Air. These twinjets are 12.4 years old on average.

You may also know that the Irish low-cost carrier operates a single 22.7-year-old Boeing 737-700. This smaller aircraft has a corporate 2-2 seat configuration, and is generally used for charters transporting groups such as sports teams across Europe.

Ryanair is also beginning to modernize its fleet, and the group presently operates 13 next-generation Boeing 737 MAX 200s. These high-density aircraft have an extra set of exit doors to facilitate a greater capacity of 197 passengers. They are just 0.8 years old on average, and the Irish budget airline also has a further 197 examples of the type on order.

Ryanair Buzz Boeing 737 MAX Getty
Ryanair Group partner Buzz will operate some of the 737 MAX 200s. Photo: Getty Images

easyJet UK and Europe

Orange-clad low-cost carrier easyJet is another airline that, in terms of the easyJet Group as a whole, operates a significant narrowbody-only fleet. Across its entire portfolio of airlines, the easyJet Group flies a total of 322 single-aisle Airbus A320 family planes.

Of this figure, 176 aircraft (around 55%) belong to easyJet UK. Of these, 69 are A319s (34 active, 13.6 years old on average), and 60 are A320s (55 active, 8.7 years old on average). It also operates a good number of next-generation A320neos and A321neos with 37 and 10 examples in its fleet, with average ages of 2.7 and 2.3 years old, respectively.

easyJet Berlin Getty
Brexit prompted easyJet to form a new EU-based carrier. Photo: Getty Images

easyJet used to base almost all of its aircraft in the UK. However, the countries exit from the European Union prompted the airline to form easyJet Europe in 2017. Based in Vienna, it is still able to operate as an EU carrier. It operates 119 aircraft in total.

Of these, the A320 is the dominant force. easyJet Europe flies 83 of these mid-size narrowbodies, and they are 6.9 years old on average. Its 32 A319s are older, with an average age of 12.8 years old. At the younger end of the scale, easyJet Europe also flies four A321neos, which are just 1.6 years old on average. All 119 of its aircraft are presently active.

easyjet Switzerland Boeing 737
easyJet Switzerland began life as an all-Boeing 737 operator. Photo: Aero Icarus via Flickr

The final piece of the easyJet puzzle

easyJet also has a Swiss division, known as easyJet Switzerland. This part of the company is a more long-running affair than easyJet Europe, having become part of the group in the late 1990s. The Swiss division has a smaller fleet, consisting of just 27 aircraft.

Of these, 22 are examples of Airbus’s popular A320 twinjet. The A320ceos that the Geneva-based airline flies are 7.5 years old on average. These are supplemented by five slightly older A319s, which have an average age of 10.3 years. Nevertheless, these small figures are a key part of the wider easyJet Group’s large and uniform 322-aircraft narrowbody fleet.

How many of these narrowbody-only airlines have you flown with? Do you have a particular favorite? Let us know your thoughts and experiences in the comments!