Last week, we talked about weekly aircraft utilization and how pulling down mid-week flights with slow demand can be problematic. But our conversation was focused on the aircraft and how you pay for it, whether you use it or not.

An astute subscriber pointed out that there are other fixed costs that can affect airlines with falling utilization: people - particularly pilots.

In 2026, the highest cost at almost all airlines is labor. While fuel certainly got close for some airlines in the recent quarter, it still largely holds true that people are the most expensive part of an airline.

Of those people who tend to want to get paid for their work, the pilot group makes up a significant portion of that payroll. The general consensus is that pilots are a variable cost. Their pay is calculated hourly, after all, so why wouldn’t they be a variable cost?

It gets complicated, but pilots are still (usually) full-time employees. While their pay is calculated hourly, it typically comes with a minimum guaranteed number of hours, pay for training events, vacation, etc. By and large, if a flight is canceled, the pilots are still paid. That makes pilots more of a complex fixed cost rather than a variable cost. Whether an airline schedules its pilots or not, it is paying them.

But what is a “good” number of pilots per aircraft? Air Canada has almost twice the number of pilots per aircraft as Allegiant. Why?

A few reasons: first, Air Canada operates its aircraft over 10 hours per day, on average. That doesn’t mean Air Canada’s pilots fly 10 hours per day (they legally can’t, anyway). But it does mean that Air Canada has to have a large enough pilot staff to operate a fleet over 10 hours per day.

But Air Canada also operates widebodies. These aircraft often operate 14+ hour days, sometimes with a single flight. This requires relief pilots, which increases the number of pilots for each flight, sometimes doubling it to four.

So not all airlines need the same number of pilots based on the business model.

But Frontier and Allegiant have a similar(ish) business model: low-cost service in the United States. With Frontier staffing 12.8 pilots per aircraft at the start of the year compared to Allegiant’s 10.7, surely Frontier is at a disadvantage, right?

Not necessarily. In 2025, Frontier operated its aircraft an average of 9.5 hours per day. Allegiant ran its aircraft an average of 7.2 hours per day. Frontier needs more pilots.

But it does make it more difficult for Frontier to pull down mid-week flying, precisely what the airline has done over the past year. Allegiant has built an airline from the bottom up with the reduced utilization in mind.

Now, consider that Frontier’s daily utilization per aircraft used to be 10.3 hours in 2024, which ultimately fell 8% to the 9.5 daily hours we saw in 2025. Allegiant was running aircraft only 6.3 hours per day in 2024, increasing utilization to 7.2 in 2025 - a 14% increase.

Another airline to stand out in the chart is Spirit Airlines. Of course, Spirit is no longer with us, but just prior to the airline’s bankruptcy filing in 2024, it was running 15.5 pilots on payroll per aircraft. That’s expensive, particularly considering the airline had already started to reduce flying, as we pointed out in last week’s chart.

Why did Spirit have so many pilots? Remember the pilot shortage after COVID? Spirit was hit especially hard. Suddenly, the rush for pilots ended, leaving Spirit with an excess it didn’t necessarily want to trim after the recent existential memories of the challenges in finding those pilots in the first place. As Spirit discovered, the only thing worse than too many pilots is not enough.

In the end, it all gets back to the idea of managing variable versus fixed costs. Which is labor? Both, actually. From a short-term perspective, your people on payroll need to be paid, whether or not you have sufficient business to keep them busy. But over time, attrition can pull those numbers back to where you want them - but not too far! For pilots, the lead time to hire and complete training just adds to the challenges.

This is just another reason why the dropping utilization of Spirit and Frontier showed early signs of distress. It’s not the utilization itself, but rather the changing of the business model. Whether it be pilots or aircraft, an airline built to operate at high utilization is going to find itself at a disadvantage when market demand forces it to slow down.

Yet, as Allegiant has proven, an airline built for low utilization can be optimized for such an operation. It’s the changes that we watch for.

We like to create valuable charts. But it’s not easy to come up with new ideas amid the endless hours spent delivering data-driven edge to our customers. In our quest to provide a valuable weekly newsletter, we can keep guessing what you find most valuable, or you could just tell us.

If you have an idea for data visualization, reply to this email and let us know what analysis you’d find most valuable. We’d love to hear from you and will happily name-drop.

As valuable as it is, don't worry; it's entirely free. If you would like to receive analyses like this regularly, subscribe below.

Then...

You can pay it forward by sending it to your colleagues. They gain valuable insights, and you get credit for finding new ideas!

Win-win!

Subscribe here