INSIGHT – Tighter and Tighter, Seat Layouts are Changing

Two metrics we utilize to measure comparative aircraft efficiency are cost per seat or cost per seat mile. Both require knowing aircraft seating capacity. In that regard, the trend has been for more seats, rather than fewer for single-aisle aircraft. Seat layouts are changing, and if you are feeling that aircraft accommodations have become more space-constrained, you are probably correct for the most common single-aisle models, the Boeing 737 and Airbus A320 families.

What’s the easiest way to increase fuel economy and carbon performance measures per passenger? The answer is to put more seats on the airplane to reduce per-passenger consumption. Seat layouts are changing, particularly for shorter-haul domestic services.

Let’s look at the trend for popular narrow-body models.

The Boeing 737-800 and the 737 MAX8 share the same fuselage. From 2010 to 2021, the average seating capacity of the 737-800 went from 157 to 162, and with the MAX 8, to 173 seats. That’s a 10.2% increase in seating capacity or the equivalent decrease in your personal space on board.

The Airbus A320ceo and A320neo also share the same fuselage. During the same period, this aircraft went from 148 to 164 for the A320ceo, with the A320neo averaging 173 seats. The neos operate only with ultra-low-cost carriers, primarily Spirit and Frontier. The A320ceo for network carriers stuffed in only 4.7% more seats. But when we select ULCC carriers, our data reveals from 162 seats in 2010 to 182. a jump of 12.3%.  Seat layouts are changing to higher densities for ultra low cost carriers.

The A321ceo and A321neo also share the same fuselage, and the average seating has moved from a low in 2014 of 176 seats to a high in 2021 of 194 for the A321neo, adding 10.2%.

The following table shows how seating capacities have changed overall for narrow-body aircraft since 2010, beginning with all US carriers. The average data by aircraft type and year are shown in the table below

For network carriers, to avoid comparing single class ultra-low-cost carriers with two-class service, data are shown in the following table. The highest gain in seats has been in the two most popular models, the Boeing 737-800/MAX 8 aircraft, and the A320ceo/A320neo, albeit more modest gains on an apples to apples basis.  Seat layouts are changing less rapidly for network carriers, but still increasing in capacity for narrow-body aircraft.

The trend for ultra-low-cost carriers shows that they have increased capacity more than network carriers, installing single class layouts that approach the exit limits of the aircraft. While these carriers did not invest in older models like the 757s used for a short period, they have invested in more recent Airbus models that most US ULCCs fly, as shown in the table below:

The trend for twin aisles has been in the opposite direction, driven by the pandemic and the use of passenger aircraft to carry freight. But seating capacities are changing again. The average seating capacity for wide-body aircraft has fallen dramatically in the last two years and has still not recovered to pre-pandemic levels. With China and several international markets still closed or hampered by restrictions, this is unlikely to fully change until 2024. But as markets open, freight in the cabin will be replaced by passengers.  As freight disappears, airlines will open additional seats to passenger traffic in accordance with demand.  But fewer passenger seats on international flights allows airlines to fly with smaller crew complements, as staffing has also been difficult during the pandemic.

Bottom Line

The most popular narrow-body aircraft, the 737 and A320 families, have been the focus of seat capacity growth. With large fleets, an investment in modified interiors can pay off more rapidly than for other models with smaller fleets. If you are flying the narrow-body trunk liners, you will notice a difference in seating capacity from a decade ago, with less personal space. While more narrow seats with more knee room are theoretically as roomy as older seats with greater pitch (the distance between rows) in practice the narrower distance is quite noticeable.

But if you are flying internationally, the trend has been in the other direction. Airlines are looking to capitalize on four classes, rather than three classes of service, and premium economy has reduced seat counts slightly for some airline layouts. Of course, the pandemic decimated international traffic, and many seats were converted to freight, with seat counts in 2020 even lower than those for 2021. While we expect a return to normal seating capacity as the pandemic wanes and restrictions are lifted, we do not expect to see a reduction in space or tighter pitch on wide-body international flights shortly.

Instead, the trend to utilize narrow-body aircraft on trans-Atlantic flights could result in a reduction of seats in some models, particularly the A321, as international business class lie-flat seats are introduced on some single-aisle aircraft. While the longest rage A321 models are still a couple of years away from entry into service, we will see changes in routes and new seat layouts beginning later this year and into 2023 and 2024.

The adage that says “you get what you pay for” will be coming to both narrow-body and wide-body international services shortly. Expect the economy to be tighter, premium economy a bit better, and business class both roomy and expensive.

Airlines are finding ways to optimize revenues wherever possible, and seating configurations are a key tool in their quivers. Seat layout changes will be interesting to watch over the next few years as carriers optimize their economics while matching capacities to demand.