Why airlines want to cram more seats on airplanes.

Have you noticed airlines are cramming more seats into airplanes?

If you're a frequent flier, you almost certainly have. American Airlines, United Airlines and Delta Air Lines are all adding so-called "slimline seats," which allow them to add more seats in the same amount of space. Legroom generally is not reduced, but the seats are slimmer, so they feel a bit less substantial. Regional airlines, like Skywest Airlines, which flies as United Express and Delta Connection, have also added the seats.  If you need more of a primer about these seats, check out a recent Associated Press article. 

Here are new seats on a United Express E175 regional jet. Notice how thin they are? Photo: DearEdward, via Flickr.

Here are new seats on a United Express E175 regional jet. Notice how thin they are? Photo: DearEdward, via Flickr.

Travelers have been complaining about the seats for awhile now. The general gripe is that they don't have enough padding. I get that. But let's take a look at some of the reasons airlines feel they must add them:

1. Costs. Operating an aircraft is expensive. But the costs are largely fixed. So if you add seats, you can make more revenue against roughly the same costs.  Here's how American Senior Vice President Andrew Nocella put it in a recent letter to employees. American is adding seats across most of its fleet, including 10 to its 737-800s, which now hold 150 passengers. 

"You already have the ownership costs  of owning the airplanes, landing fees are there whether you have one seat on a plane or 100, and those other fixed costs all come into play," Nocella said. "To add product — capacity — without materially increasing our costs will drive increased profitability." 

I know "profitability" is not a word that registers with travelers. But other airlines have put it differently. Take Frontier, for example. Frontier executives said if they cram more seats on aircraft, they can keep fares low.

2. Weight. The new seats are materially lighter than the ones they replace. That means a flight could cost slightly less in fuel, a difference that adds up over time. Here's what Lufthansa says on its website:

"The new seats are lighter. Each seat weighs 10.87 kg. We save a total of 14.304 kg in weight. That means we need less fuel and produce fewer emissions, which is better for the environment."

3. Customer comfort. I'm not sure if I buy this one, but I hear it all the time, so I'll include it.  Many carriers claim that these new slimline seats actually perform fairly well in customer satisfaction surveys. They are generally clean and new and look pretty sharp, which I am sure helps. They also have one material design improvement over the seats they replace. The magazine rack is usually higher on the seat -- closer to eye level than knee level. So you may feel as though you have a bit more knee room.

Here's what Delta executive Mike Henny told me late last year for my former blog, L.A. Airspace.

We put a lot of effort in looking at the design of the seat and the structure of the seat, so that if there are ways for us to make it more comfortable, we have done that. We have worked with the manufacturer to try to get the best equipment that we can possibly get so it is as comfortable as possible. Ultimately, the goal for us is for you as a customer to get on the aircraft and think, ‘This is a clean modern aircraft and I’m in a comfortable seat and I’m going to enjoy my time here.’