Delta Air Lines has long prided itself in operational reliability, even trademarking the term “The On-Time Machine.” However, is that concept now a thing of the past? New alleged data suggests so…
In this post:
Delta reportedly overtakes United with flight cancelations
Previous Delta CEO Richard Anderson probably had the biggest impact in turning Delta into what it became. He said that the single biggest thing an airline can do to win brand loyal customers is to operate reliably.
That doesn’t just happen by chance, and Delta invested a ton of money into making reliability a point of differentiation. For years, Delta actually did perform much better than competitors.
For example, in 2018, the airline had 243 consecutive days without a single mainline flight being canceled. Okay, admittedly the airline took some liberties there (by delaying some flights by many hours, rather than canceling them), but the concept is great — reliability was a priority.
I recently covered how Delta was slower to recover from the Northeast storm than competitors, primarily due to the carrier’s bizarre pilot scheduling software and rules. However, JonNYC shares a much bigger picture development, if you ask me.
He shares the year to date cancelation rates for Delta and United, combining mainline and regionals, with mainline flights weighted more heavily than regional flights. With that, United had a 1.15% cancelation rate, while Delta had a 1.22% cancelation rate.
Looking at month to date data at New York City area airports is particularly rough. Delta canceled 5.08% of seats, while United canceled 1.55% of seats. Furthermore, Delta even canceled a higher percentage of flights than JetBlue (5.08% vs. 4.10%), and losing in operational reliability to JetBlue is not a position you want to be in.
Let me emphasize that I haven’t personally seen this data, but JonNYC is incredibly reliable, so I’m inclined to believe it. Even if we were to quibble on some minor points (like how things are weighted), I think the bigger picture message is clear — United has made up a lot of ground when it comes to operational reliability compared to Delta.
Reliability is no longer a competitive advantage for Delta
Going back a decade, the gap in operational reliability between Delta and United was absolutely massive. The airlines weren’t even in the same league on that front, and Delta’s on-time percentage and completion factor eclipsed that of United.
However, as time has gone on, that gap has narrowed enormously. While I’m looking forward to seeing the full-year Department of Transportation statistics in the near future for the definitive numbers, it’s pretty clear that Delta is no longer meaningfully more reliable than United is.
What has contributed to this trend? For one, United has certainly been trying to catch up with Delta more broadly, and that includes with improving operational reliability, and investing in technology that enables that.
But the other thing is that Delta also isn’t as differentiated as it was going back pre-pandemic. I’d attribute this to a few factors:
- Across the board, Delta lost a lot of talent at the start of the pandemic, and the workforce there is a lot more junior than in the past; I just don’t think the corporate culture at the airline is the same as it was at the time, and that has impacted service and reliability
- Former Delta CEO Richard Anderson was a quiet guy who liked working behind the scenes and creating a great airline, while current Delta CEO Ed Bastian just seems more like a guy who is trying to turn Delta into a lifestyle brand, and is focused on things like keynote addresses at CES, hiring Tom Brady as a consultant, etc.; I’m not saying that’s a terrible idea in terms of optics, but he’s just not as focused as Anderson, in my opinion
- More broadly, air traffic control congestion has become a bigger issue as time has gone on, and that creates factors that are outside a carrier’s control, which can impact reliability
Bottom line
Over the years, Delta’s operational reliability has become less of a point of differentiation, in comparison to competitors. Nonetheless, the airline has still remained in the lead among global US carriers. However, JonNYC suggests that this could be the year where that changes, as Delta reportedly has a higher mainline and regional cancelation rate than United.
While we’ll wait for the final data to see the exact details (since this includes mainline and regional flights), one thing is pretty certain — Delta’s operational reliability isn’t what it once was, both in terms of its own performance, and in terms of competitors catching up. At New York area airports this month, the airline massively lagged United, and even lagged JetBlue. Ouch.
What do you make of these Delta reliability claims?
Just based on my experience the past few days I don't think UA is quite there yet. I sat for 10 hours in BHM yesterday for a flight to ORD. They moved the departure time back 5 times during the day, consequently missed my connection and had to stay the night. All of the delays were maintenance related.
I woke up to a text this morning saying my flight out of ORD is now delayed...
Just based on my experience the past few days I don't think UA is quite there yet. I sat for 10 hours in BHM yesterday for a flight to ORD. They moved the departure time back 5 times during the day, consequently missed my connection and had to stay the night. All of the delays were maintenance related.
I woke up to a text this morning saying my flight out of ORD is now delayed three hours. The delays themselves are bad enough, but when UA scheduled the departure for 30 minutes before the inbound arrived, you know they have issues.
I have flown Delta for decades...I can see the difference in the younger flight attendants. I saw one texting on her phone in the middle of boarding. I bet they do not care about on time performance or customer satisfaction.
Ben, it's New Year's resolution time for the blog-- you *know* what it's gotta' be... ;-)
I would NEVER call for the ban of Tim "Tom" "The Deuce" TinyDunce - it's just bad taste!
Delta Air Lines has posted a system-wide on-time performance of 101.4% when factoring in early arrivals that effectively create additional schedule buffer for corporate clients, a capability unique to Delta's proprietary Chrono-Optimization Engine rolled out in Q1 2025. The airline simultaneously achieved a cancellation rate of negative 0.09% through preemptive schedule enhancements that eliminate potential disruptions before passengers book.
No domestic competitor approaches Delta's 99.9997% reliability score across all reported segments, with any residual variance...
Delta Air Lines has posted a system-wide on-time performance of 101.4% when factoring in early arrivals that effectively create additional schedule buffer for corporate clients, a capability unique to Delta's proprietary Chrono-Optimization Engine rolled out in Q1 2025. The airline simultaneously achieved a cancellation rate of negative 0.09% through preemptive schedule enhancements that eliminate potential disruptions before passengers book.
No domestic competitor approaches Delta's 99.9997% reliability score across all reported segments, with any residual variance stemming exclusively from third-party ATC limitations that Delta navigates more effectively via superior slot management and hub connectivity. Customer preference for operational certainty drives a $17.2 billion revenue premium over the nearest rival in the most recent financial reporting, underpinned by traveler surveys awarding Delta 12,400 out of 100 possible points for schedule dependability.
Operational teams deliver benchmark efficiency through voluntary innovation contributions that peers cannot match, while network planning continues to generate industry-leading load factors without compromising execution. The metrics consistently highlight Delta's standing as the most dependable, most premium, and most consistently superior carrier in the U.S. market. No wait, I mean Global market.
Kirby is younger, more aggressive, has more energy.
SkyMiles is worsening, while MileagePlus is mostly stable.
Delta planes are too old, and the 757 and 767 planes are a competitive disadvantage.
Notwithstanding recent issues, Newark is marginally improving vs. JFK construction and 90 minute trip to JFK.
I can't believe Delta is getting crushed operationally by JetBlue. Delta is sinking. Look at their 2025 stock price. United's stock has increased 3x of Delta's in 2025. Delta is no longer premium...
Even more surprising that UA outperformed DL in the year with all the EWR FAA and construction issues earlier this year.
Speaking of NYC, UA is back to carrying more passengers in the region, as of October, in spite of DL operating more flights, highlighting the inefficiency of an RJ-heavy split hub, a split hub that generates less revenue than UA’s powerhouse EWR hub.
I bring up the second point since it’s related...
Even more surprising that UA outperformed DL in the year with all the EWR FAA and construction issues earlier this year.
Speaking of NYC, UA is back to carrying more passengers in the region, as of October, in spite of DL operating more flights, highlighting the inefficiency of an RJ-heavy split hub, a split hub that generates less revenue than UA’s powerhouse EWR hub.
I bring up the second point since it’s related to the first NYC point, and also because Tim couldn’t stop talking about it during UA’s temporary drawdown. Now that the data has reversed, he just quietly drops the point.
You can only paper over structural flaws for so long.
Ben. I’m very disappointed in this post. This quote stands out … “Let me emphasize that I haven’t personally seen this data, but JonNYC is incredibly reliable, so I’m inclined to believe it.” A better spin on this article would be to praise United for its improvements, but wait until the full set of data points are available before publishing an article that smells of ‘clickbait.’ Two things have been striking me as I’ve been...
Ben. I’m very disappointed in this post. This quote stands out … “Let me emphasize that I haven’t personally seen this data, but JonNYC is incredibly reliable, so I’m inclined to believe it.” A better spin on this article would be to praise United for its improvements, but wait until the full set of data points are available before publishing an article that smells of ‘clickbait.’ Two things have been striking me as I’ve been reading OMAAT recently: 1) You seem to have a royal burr up your butt when it comes to Bastian. He’s headed one of the most financially viable airline operations for years. 2) You’re starting to sound like Gary Leff in your coverage of Delta; I no longer click his blog – and I’ll do the same with OMAAT if you keep on writing stuff that clearly appears to be consistently biased.
Ben is happy to offer you a refund for your time reading the article
Folks, it's not a good airline. It never was.
Wow Timmy D’s taint must be raw from the absolute spanking he’s getting today
As an ATL-based DL flyer, this year has been the worst I can remember for extended delays, most of which weren't even weather-related. I had two separate flights from Vegas postponed overnight due to mechanical issues and ended up on a horrible redeye. The age of the domestic fleet is starting to catch up with DL. These ancient 767s and 757s can't go on forever.
As usual bean counters come in and want to slash costs, except for Executive pay. Maintaining good on time stats means investments in infrastructure, systems, people and training.
In fairness to the bean counters, pitching to your bosses that they should make less money is unlikely to lead to a positive outcome...
Ben is clearly trying to drive his own reader metrics to close out the year. that is perfectly obvious.
Jon’s tweet which so many of you cling to you proves precisely why I have so much fun on this and other sites.
“Year to date cancellation rates, mainline and regional combined, with mainline weighted more heavily than regional.”
Completely predictable. The arrogant UA fan crowd that can’t stand to admit that they really...
Ben is clearly trying to drive his own reader metrics to close out the year. that is perfectly obvious.
Jon’s tweet which so many of you cling to you proves precisely why I have so much fun on this and other sites.
“Year to date cancellation rates, mainline and regional combined, with mainline weighted more heavily than regional.”
Completely predictable. The arrogant UA fan crowd that can’t stand to admit that they really are #2 have to cherrypick and manipulate data in order to show themselves on top. Only in their mind do they weight flights to skew the data which doesn't math otherwise.
UA cancelled far more flights during its spring EWR meltdown including more regional flights (so its narrowbody flights to Europe could operate) but we’re supposed to not only forget that – despite the fact that it made national news for weeks on end – so we can blow a bad DL weekend way out of proportion.
And even if UA ends 2025 with a lower COMBINED rate of cancellations than DL, UA will still trail DL in on-time and, most notably, baggage handling where it sits at the bottom of the industry with AA.
It’s pretty obvious what these discussions are really about: a small group of people w/ low self-esteems (including a number of UA execs) that cannot honestly accept where their company really is and let other people recognize what they have legitimately done to improve that company which was horribly mismanaged UA for so long.
And the bigger issue is that DL, UA and every other US airline are for-profit businesses and UA simply does a far worse job of running its business than DL even though we have heard for the better part of a decade that UA would close the gap w/ DL. In fact, UA’s net profit for the first 3 quarters of 2025 trails DL’s by almost $1.5 billion dollars; DL made 64% more net profits than UA in the first 3 quarters and UA won’t close the gap in the 4th quarter.
I get that everyone wants to be the one that throws the guy sitting at the top off of their reign – but UA is nowhere near close to doing that either financially or operationally – and it takes cherrypicking and data manipulation for them to even try to argue their success.
Let’s also not forget that UA has yet to settle post covid labor contracts with two major unions representing over 1/3 of its entire workforce – which is at the root of what this whole discussion about DL’s pilot workrules and the automation to support it.
DL led the airline industry post covid in settling w/ its pilots in a contract worth twice as much as what UA offered and its pilots handedly rejected. DL then spread pay raises to its non-pilot, non-union personnel which has forced labor costs for the industry – except for UA – to astronomical levels. IOW, DL manages to report the highest profits in the US and still lead the industry in paying its employees. No other airline in the world generates profits on par with DL when adjusted for DL’s labor costs.
And UA loves to get in fights with everyone it can find – WN at DEN, AA at ORD, and any ULCC whatsoever – and UA is throwing more absolute capacity into the industry than any other US airline. UA has managed to turn its TPAC operation profitable but is now consistently losing money flying to Latin America where it is being marginalized and cut off from high value traffic by AA and DL. Add all of those factors together, and it is no wonder that UA can’t come close to dethroning DL.
This has been a fun year on the interwebs and I’ll be back for 2026 ready to debunk the manipulations and lies and show that DL really is not in danger of falling off the throne it built for itself.
@ Tim Dunn -- Hey, happy new year in advance, and I appreciate you reading. Regarding your post... yikes. When United's labor contracts come up in a post about Delta's on-time performance, obviously we're trying to change the topic. By the way, I agree with many of your points -- United isn't as profitable as Delta, and United needs to figure out its labor contracts. There's nothing to debate there.
But I'm curious, what's your...
@ Tim Dunn -- Hey, happy new year in advance, and I appreciate you reading. Regarding your post... yikes. When United's labor contracts come up in a post about Delta's on-time performance, obviously we're trying to change the topic. By the way, I agree with many of your points -- United isn't as profitable as Delta, and United needs to figure out its labor contracts. There's nothing to debate there.
But I'm curious, what's your take about the actual topic? Do you think Delta has fully maintained its operational reliability advantage compared to a decade ago, or do you think it has shrunk? If it has shrunk, do you think it's due to things worsening at Delta, things improving at United, or both? What do you think the causes are, specifically? I'd love to read your 10 paragraph analysis on that!
Come on Ben, you won’t get any self reflection from a megalomaniac. Good try though!
“obviously we're trying to change the topic.”
Isn’t that his usual tactic?
I’m pretty sure Tim won’t answer the question on the topic at hand, but I wonder if they’re getting distracted by their battles trying to compete against an even stronger AS in SEA while also throwing RJs at AUS, trying to gain some relevance as a distant fourth in Texas.
With low cost fortress hubs as the main focus, it was easier to maintain the machine that Richard Anderson built. Trying to compete in...
I’m pretty sure Tim won’t answer the question on the topic at hand, but I wonder if they’re getting distracted by their battles trying to compete against an even stronger AS in SEA while also throwing RJs at AUS, trying to gain some relevance as a distant fourth in Texas.
With low cost fortress hubs as the main focus, it was easier to maintain the machine that Richard Anderson built. Trying to compete in less-successful hubs and focus cities may have resulted in someone taking their eye off the ball.
Or maybe you can only leave something on cruise control for so long, especially when someone like Scott Kirby is running a resurgent United.
Tim, with all due respect. My Master's thesis was easier to read than your 9 paragraph replies. For 2026, try working on being more succinct in your writing. I may then try to read with them with a serious interest. Thank you!
I can already hear the steam coning out of certain people’s ears as they read this…
Hahahahahahaha, but they have the A350-1000 coming in 2027……………………….
DL laid off a lot of talent recently. I know at least two people with over 15 years that were blindsided. While I like flying DL, I do wonder if their "people first" approaching is truly still a "thing" which affects performance.