Running an operation at a time when schedules are changing frequently and close to departure is not for the faint of heart. Things get even more complicated when airlines purposefully decide to cancel at the last minute for commercial reasons, not operational ones. The pandemic has created an alternate universe where crews and spare airplanes are in endless supply, but flights still have canceled, much to the chagrin of the few passengers that still exist.

I decided it was time to check in on the operations and see if flights were still being canceled en masse or if they had stabilized. After looking at the data in masFlight, it looks like indeed they have improved… for the most part.

Let’s start with a look at the Big 4 airlines. This is the completion factor, or the percent of scheduled flights that actually operated.

Now, before you skewer me for distorting the axis, just know that if I showed you from 0 to 100 percent, you wouldn’t be able to see much at the top end. So just be mindful that this starts at 80 percent and the changes aren’t as big as you might otherwise think.

What you can see here is that things started off terribly at the beginning of May. That’s because the “May” schedule didn’t actually start until a few days into the month. Those early days were still part of the chaotic april schedule where flights couldn’t be canceled quick enough or far enough in advance to avoid showing up as cancellations.

Once that settled, however, you can see that American and Southwest instantly began running a consistent operation. United and Delta had more of a steady increase in reliability over that time with Delta running in last place. But do note that within the last week, everyone has started running well.

Now, let’s look at what I’ve lately taken to calling the Tweeners.

Keep in mind that with these airlines, there are fewer flights operating so one cancellation impacts percentages more heavily, and that’s especially true with Hawaiian. See that devastating drop to just over 95 percent for Hawaiian on May 9? Yeah, that’s because the airline canceled 2 flights from its barebones schedule. Hawaiian is running a very solid operation.

JetBlue on the the other hand, is not. Or should I say, it wasn’t running a solid operation. It was canceling flights like crazy, but things improved markedly and since June 9, it has settled down.

Alaska is an interesting one since it had improved toward the end of May, but it has been backsliding. Alaska is the only airline in the last week that hasn’t been running over 99 percent completion, so I asked what was going on. Spokesperson Ray Lane explained:

There are a few different factors driving [Alaska and Horizon] completion rates below where we’d like them to be as we make the transition from our June to July schedule. In general, it’s linked to capacity we had recently added across a handful of markets that we ultimately ended up pulling back. This will flow through stats over the next couple of days.

Interesting. So Alaska added flights and then changed its mind. Whether that’s due to demand weakness or something else, I can’t be sure. But still, that’s something to note.

Now, let’s take a look at the ultra low cost carriers (ULCCs).

Let me start with the obvious. Spirit is doing a remarkable job and has been the whole time. Frontier settled down in early May and has been doing just as well ever since.

Then there’s Allegiant.

Allegiant’s operational details are admittedly spotty in the data. You see plenty of gaps in the chart, and that’s because there are some days where I just don’t see any numbers. That’s not ideal, but this does certainly paint a picture anyway. Allegiant is an airline that has been canceling like mad. It has had very limited schedule integrity, and that is particularly frustrating considering there are few if any other options in most of its markets. Something tells me that Allegiant has not been making friends.

The good news is that in the last week, things have changed completely. Since June 17, Allegiant has completed every flight scheduled except on one day. That day it still ran over 99 percent. (There’s another day with no data, but I’ll give the airline the benefit of the doubt.)

So, it appears that we’ve reached a point where airline schedules are now more reliable than they have been at any time in the last three months. That’s the good news. The bad news is that this could change at any minute, as we can see with Alaska in the last week. If demand drops due to COVID concerns or anything else, schedules will change and operations can change just as swiftly. It’s still a fragile system right now.