Delta cancelled nearly 700 flights in three days, long after other airlines had recovered from New York weather. The surprising culprit wasn’t lingering storms or air traffic control—it was a pilot-union contract catch-22 that can make last-minute pilot assignments break down when disruptions create open trips.
A couple of days ago I wrote about Delta’s terrible operational meltdown. It began with weather in New York, but everyone else’s operations recovered. United and JetBlue, both with New York hubs, didn’t suffer the way that Delta did.
Delta used to go months at a time without cancelling a mainline flight. Over three days, they cancelled nearly 700 flights. And it’s because the airline was unable to assign pilots to flights.
It wasn’t quite clear why they were having so much more of a problem than everyone else. It’s always tougher to find crew with available hours left to pick up trips at the end of a month, and willing to do so over the holidays. But make no mistake, aviation watchdog JonNYC had revealed the issue was Delta simply couldn’t match pilots with trips.
Aviation watchdog JonNYC shares dispatch notes from one cancelled flight,
“You have no clue how F’d Delta's pilot coverage system is… Dispatch started writing in the cancellation remarks…’FLT CXL- Flight Operations-Crew uncovered- Normal Ops’
Dispatchers are just as pissed as the pilots are”— JonNYC (@xJonNYC) December 28, 2025
Let’s take a closer look at ’FLT CXL- Flight Operations-Crew uncovered- Normal Ops’
- Flight was cancelled.
- The cancellation is being attributed to is an operational issue – lack of crew – not to maintenance, weather, air traffic control, etc. They didn’t have the crew available to operate the flight.
- But what’s key here is ‘Normal Ops’. This isn’t being handled under an ‘irregular operations’ event context like a major weather day. We’re past that. They’re labeling the flight as crew coverage failure on an otherwise normal day.
Delta was acknowledging, “nothing external is blowing up the network right now, and we still can’t cover the flight.” Even if dispatch didn’t type “normal operations” as editorial snark (it looks like a standard structured suffix), it still lands as a jab.
It seems we now know the why. One Mile at a Time points to this detailed explanation of the Rube Goldberg procedures in the Delta Air Lines pilot union contract that forced flight cancellations.
[B]oth the pilots and the company are exercising contractual loopholes that have crippled the company’s ability to staff trips that become open with less than 18 hours to departure.
Ironically, it started when the company introduced some new software to try and improve the situation. Several years back, the company introduced a 3rd party crew staffing app (ARCOS) to help automate some crew scheduling processes. Prior to this software, the last minute overtime coverage (“Green Slips” / double pay) was done manually by a crew scheduler and if they got the pilot on the phone, the trip was theirs. With this software, the company could contact pilots in groups (“batch sizes”) instead of 1 at a time. This created situations where pilots would be woken in the middle of the night to acknowledge a trip that they in fact would not be given because 10 pilots had been called, but only the senior pilot who acknowledges gets the trip. So, they negotiated an option to “auto-accept” a trip which would then give them a 12 minute window to contact the company and acknowledge the trip. Eventually the company decided that they didn’t want batch sizes and ALPA essentially gave away batch size limits for free (a controversial move). Now that the company could call everyone at once, this created more nuisance calls in the night which drove up the use of the auto-accept feature. More recently, they negotiated to also have this same app be used for normal last minute pickups (“White Slips” / standard pay).
Because of the increase in auto-accept and reduced staffing in crew scheduling, the company found they were having trouble staffing flights. So, they turned to a previously obscure and little used function in the contract called 23M7 which allows them to skip all of the coverage steps (the app) and simply award a trip to anyone they can get on the phone (“Inverse Assignment”). In order to do this, they pay the pilot who flies the trip 2x pay and then they have to identify a “harmed” pilot who was skipped over (since they skipped the app) and pay them 1x pay. It costs Delta 3x to staff trips this way, but it eliminates all the steps that are normally followed – making it much easier for a crew scheduler to get the trip covered. The proliferation of this method of staffing has created an even greater use of the “auto-accept” feature of the app because a pilot has to have this feature turned on in order to potentially become the 23M7 “harmed pilot” and get 1x pay without having to fly.
So, let’s say a trip needs a new captain 12 hours before departure. They will begin to ask pilots through the app if they want the trip, but imagine in a large base (ATL 320) that 200 pilots have “auto-accept” turned on. That means that each of them has 12 minutes successively to acknowledge the trip. As you can see, the math doesn’t math and they then have to go into the emergency coverage step / 23M7. All of that is a manual process though and they have staffed the department at a level that expected / anticipated automation.
Weather may be the initial cause of why a flight needs new pilots, but make no mistake – the reason they are cancelling like this is because of this contractual catch-22 they find themselves in.
In essence, Delta moved trip coverage (at premium pay) from manual scheduler phone calls to an automated crew-staffing app which let Delta contact pilots in groups instead of one at a time, which created nuisance calls (pilots awakened to respond even though only one would actually get the trip, assigned based on union seniority).
In response, pilots negotiated an “auto-accept” option that provides a 12-minute window to contact the company and acknowledge the trip. Eventually, the airline and union allowed everyone to be called at once, which increased nuisance calls and further increased auto-accept usage. The app was expanded to also cover standard last-minute pickups, not just premium pay trips.
With more auto-accept and fewer crew scheduling staff, Delta had trouble covering flights, so it relied on a contract provision called 23M7 that skips the app process and awards a trip to anyone they can reach by phone.
- Delta pays 2x to the pilot who flies the trip, but must also identify a “harmed” pilot who was skipped and give them regular pay for not flying (3x total cost).
- But to be eligible to get paid for not flying (to be ‘harmed’) a pilot must have auto-accept enabled, signaling they were available. So even more pilots started using auto-accept.
Here’s where things break down. If a trip opens 12 hours before departure and 200 pilots have auto-accept on, giving each 12 minutes successively makes timely coverage impossible. It’s a contractual catch-22. There’s just not enough people calling and not enough time to make it through everyone that needs to be called.
A sequence of contract and software changes created incentives that ballooned auto-accept usage and pushed Delta toward a manual, expensive bypass (“23M7”) for last-minute coverage. That bypass then further increased use of auto-accept, worsening the underlying timing and staffing problem. And that’s created operational fragility that shows up as cancellations when disruptions create open pilot trips.
So…I’m thinking outside the box, but could Delta just…I dunno…go back to the old system and abandon the technical fixes?
When you quote someone that uses F words to describe operations, no one takes them seriously.
there has been a thread on APC since Dec 5 on ARCOS.
As usual, neither you or Jon referenced that thread. But when you are more interested in tweeting, you don’t take the time read what actual DL pilots are saying or understand the issues.
and, as for the speed of DL’s recovery, DL cancelled the same percentage of JFK flights on Saturday as B6; on Sunday, MSP had 4 hour ATC delays for snow and ice at time and yesterday DTW had ATC delays due to runway construction (like, who does runway construction in Michigan in the winter?)
DL hasn’t had a day since the NYC storm when it had no IROPS in one of its hubs – until today.
and DL still has the best combination of system on-time and lowest cancellations year to date of its NYC competitors – and the rest of the industry.
And AA and UA both are at the bottom of the industry in baggage handling
Yeah, DL and DALPA have to fix this but it won’t move the needle in DL’s rankings for the industry in 2025.
::popcorn:: for dunn’s explanation
Ok, so Delta has identified they have a problem that has contributes to taking them from zero cancellations over a period of months to hundreds of cancellations in a period of hours.
So, the question is, what is DL going to do to fix the issue? Are they going to even try to fix the issue.
So much of what’s happening at Delta right now is self-inflicted.
These Tim Dunn quotes didn’t age well.
“or is it possible – or actually reality that field conditions at JFK and EWR are not the same.”
“and MSP had 4 hour delays – which is to the point that ANY crew is going to time out.”
“So, yes, DL is having trouble staffing but I have yet to see anyone provide evidence that actually supports the much higher numbers of cancellations.”
“once, again, if this was all caused by a DL staffing problem, then why did B6 cancel 17% of its flights”
“The obvious reality is that all 3 NYC airports did not experience the same levels of impact
so, it is a pure lie to say that DL alone was impacted.”
I was a crew scheduler back in the day when we used the phone during irregular ops. And reverse seniority. If a pilot answered his/ her phone, they were effectively Junior-manned (or whatever it would be called today) and that is how we covered trips. Sometimes, though not very often, we would have to cancel for no crew available.
JL,
none of what I said is wrong.
MSP still had 4 hour delays Sunday, DTW had ATC delays yesterday.
and since you see everything as a pi78ng match, the DOT has just released profitability data by global region for the 3rd quarter. The DOT confirms that UA loses money flying to Latin America. In fact, UA hasn’t been profitable this decade flying to Latin America. It shouldn’t be surprising given the horrendous RASM drop they had to Latin America in the 3rd quarter – worse than drops in every other region.
it’s that whole speck and log thing.
DL runs a far better operation and business. You would be wise to walk away from throwing stones.
There is ALWAYS more dirt to find about UA than about DL.
TD, “none of what I said is wrong.”
Yikes! Someone get this guy a feedback loop.
Don’t worry, these weren’t normal cancellations – they were Premium™ Sky™ Cancellations™ and all the customers loved them and opened up three more Amex cards.
What’s the reasoning of having the 12 minutes allotted to respond successively when they are sent out to all of the pilots in parallel? Also, if they all have auto accept on why would they wait for 12 minutes to record the response?
Did you bother to read that there has been a discussion on APC since Dec 5 about ARCOS.
The only feedback loop that is missing is that you are incapable of comprehending that it was the weather that caused the IROPS problems.
None of Ben, Gary and most certainly not Jon had any clue about ARCOS for the entire month of December.
DL managed to do just fine until the bad weather hit
On a different topic, but one that has been discussed in this site, and related to automated scheduling making things worse. Wait until somebody decides to use AI to do the scheduling. The SNAFUs are going to be much worse, more widespread, and significantly harder to fix.
DL and ALPA need to go back to the old system and fill open time. Make it rain green slips to get the operation back to normal. No one is going in during the holidays for straight pay.
There’s too much reliance on scheduling automation at all airlines, trying to reduce headcount in crew schedule.
The schedulers have all the available pilots at their fingertips, and priority of who gets the next legal trip. Management has hamstrung the schedulers at their own peril.
TD, “None of Ben, Gary and most certainly not Jon had any clue about ARCOS for the entire month of December.”
Neither did you as evidenced by all your absurd arguments above unless it was you who is lying. A stunning lack of self awareness.
the pilot gets it and I don’t think he is even a DL pilot.
and I strongly suspect they have pulled ARCOS – which is NOT a DL specific product.
and the arguments only are wrong to you because you don’t understand what was going on before this weekend, during this weekend, or now.
and none of Gary, Ben or Jon are capable of understanding or explaining it
Why not stagger the windows 1 minute apart and overlapping? They acknowledge the trip within their window but the pilot that got notified first and replied within that pilot’s window gets the job.
TD, “I strongly suspect they have pulled ARCOS – which is NOT a DL specific product.”
Who cares? DL decided to use their product just like they chose to use CrowdStrike.
of course you don’t care.
Tell us what vendor UA uses for its baggage handling system that does a pathetic job not just during IROPS but day in and day out.
and you still haven’t explained how UA managed to cancel more flights in 2024 than DL despite UA operating a smaller number of flights and UA supposedly not getting hurt by CRWD. Just what did UA do to end up w/ a much worse cancellation rate and absolute numbers, JL?
Made the mistake of booking Delta for a Christmas day trip from ATL to BOS in 2021 and watched the monitors in the SkyClub as the flight delay increased by the hour (no crew) until we finally took off some 8 hours later with unseasonably mild weather up and down the East Coast. Every other DL non-stop flight was cancelled.
On a positive note, we landed with enough time to still grab a late night holiday dinner at a fabulous Italian restaurant (Trattoria) in the North End near the TD Garden.
There’s so much twisting into on knots on this thread you’d think we were in a pretzel factory.
Kinda fascinating to watch people argue from entirely different realities: one rooted in data and context and the other rooted in belief and want. It’s like watch two different media outlets covering the same story.
Looks like Delta slipped on a premium banana peel.
The fact that nothing is due to customers is why you see this. If the airline had to pay $600 to each disrupted customer as it would in civilized countries this would be fixed immediately.
Put blame where it’s supposed to go: the US Government lack of regulation to protect Americans.
“Put blame where it’s supposed to go: the US Government lack of regulation to protect Americans.”
Actually it is worse than that. The law actually sides with big business in this case. If not there would be class action lawsuits that would change the situation.
Just love seeing every trick in the Tim Dunn playbook here. It’s like someone told ChatGPT, “Just f***ing defend Delta. Doesn’t matter if it’s logical. Doesn’t matter if it makes sense. Doesn’t matter if it’s consistent. Doesn’t even matter if it’s coherent. Just type out 300 words that muddy the waters.”
Denying that his words meant what they meant.
Juvenile insults.
Rewriting history.
Long-winded posts that prove nothing except that Tim knows how to hit keys on his keyboard.
Throwing in some useless facts about United and AA that have absolutely no relevance to anything.
Typing speculation without offering proof.
Reminds me of the time when Spirit had a bunch of cancellations and Tim said customers have an expectation that airlines will fly their schedules, but then Delta had a bunch of cancellations and Tim said it was no big deal because Delta accommodated everyone on later flights. Just absurdly inconsistent. (Tim, let me know if you want me to tell everyone where to find the original posts.)
“If weather persists, then airlines should adapt their operations.” — Tim D. in 2021
Really enjoyed seeing a couple of my old favorites:
“And you still haven’t explained how …” — oooh nice Tim. You called someone on the carpet for not explaining something that has nothing to do with the original post or their original comment — the argument only came up because you threw it out to distract. Sizzling debating skills there, Tim.
“The only xxxxx that is xxx is that …” — solid comeback Tim, you tossed out your most sizzling, most original zinger.
Tim, you attacked Gary for not “understanding the issues.” Could you clarify what exactly you think he got wrong? I don’t see anywhere that you actually did that.
https://x.com/xJonNYC/status/2006156683186430396
Highlighting how far they have fallen, DL and its regionals have canceled more than UA and their regionals, even with UA dealing with all the FAA/EWR issues back in the spring.
DL, month to date, has canceled more than B6 in NYC.
As of October, DL carries fewer NYC passengers than UA while operating more flights, showing how inefficient their operation has become.
It seems like their battles as a distant number two in SEA and AUS are causing DL to take their eye off the ball.
At least the money they save by not investing in IT, for employees or for customers, will help prop up the profits.
Tim Dunn is so stuck in his personal Delta narcissim circle that he doesn’t realize that we see thru his creative statistics. While most of us find him annoying and his use of very selective statistics miss the point he is interesting. As annoying as he is and being former airline management and aboding in the Atlanta area he is a character that I would buy a beer and engage in debate with. Who knows maybe I am wrong but as a multi million miler and decades of Diamond, I gave up on Delta for a few reasons but lack of service and standards were the key reasons and frankly, I am happy at United. If he wants to talk smack about American I would join him. Every airline has issues and Delta’s seem to be obvious lately. Too bad some people don’t see the forest thru the trees.
So great seeing TD reference 2024 as if that matters as we’re about to enter 2026….it’s not what you did for my years ago, it’s about what you’re doing to get things fixed quickly today that TD seems to be confused by
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.
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.
Let’s not disparage Delta and their scheduling system; they CLEARLY have a “premium” method for filling piloting needs (and afterwards, passing on a premium cost to their customer base).
@Tim Dunn My Delta flight was cancelled who can I talk to at your company for a refund?
@Tim Dunn,
You have mentioned American four times, despite Gary not bringing them up at all.
You have mentioned United 29 times, despite Gary only mentioning them in passing.
You have typed 1,171 words in response to this article alone. Yet you still haven’t articulated a single thing that Gary got wrong in his original post.
@ Gary — Between here and OMAAT, I think Tim Dunn may have stroke today. Looks like DL is no longer most realiable airline. Profitability will drop below UA next.
I am having fun today… just another beautiful day in paradise.
the only people that are having strokes are those that thought they could “weight” mainline data to come up w/ a means to put UA on top of DL and didn’t realize they were going to get caught w/ their hand in the cookie jar.
@Tim Dunn YOU DO REALIZE if you are having a great day being so wrong about so many things you really need to consider seeking professional help. You have a problem.
Wishing you everything in 2026 you put out into the world.
This is really interesting, because on my last flight with Delta this year which was in December – their poor performance had me selecting other carriers – one of the SlyClub attendants talked about the reserve scheduling system, or ‘on call’ system, basically being turned ‘off’ for now. Everyone scheduled was actively working and had flights scheduled, with no slack in the system. I have no idea if this is what is being talked about in this article, but basically, what I understood, is that if there was a timeout, there was no one slotted to pick up flights without crew at the hubs. One seemed a bit surprised by this, and the other didn’t seem to think it was a good thing. Probably because they are going to hear about it. They are part of that front line person that Delta still has that is really quite good.
What it comes down to is that Delta management is being very short sighted operationally, and really does not care much anymore about the impact on passengers. Maybe they think being marginally better than other carriers is good enough, and that they can pretend that they can blame it unusual events while pointing to JD Powers. I think the fact that they are NOT seeing revenue in the Economy section is writing on the wall they are choosing not to see.
Parker,
if you think that I am being proven wrong by manufactured data that weighs mainline flights, then it is you that need professional help.
The only thing worse than Jon’s manufactured data is that Ben and Gary bought it hook, line and sinker.
Data is great – and Gary posts it on many subjects often. I can’t for the life of me understand what Gary thinks he saw in Jon’s post and why he didn’t any more due diligence before he posted it.
And I do have fun in pointing out that DL, according to the latest DOT data – which goes through Sept – is still well above every other US airline in on-time except for HA – which will be dissolved into AS before very long.
Happy New Year to you anyway.
I’m bases in NYC and Delta still got me to where I was going during this period. Yeah, sometimes it’s the weather, other times it’s on them. This seems like a situation where an EU-261 rule would’ve benefited affected passengers. Even if it doesn’t fix everything, a several hundred dollars in addition to rebooking or refunds helps. Sad to see my friends above fighting each other. Glad to see this discussion did not descend into bashing the pilots union at least… phew!
1990
Happy New Year.
As I have stated before, the real statistic that matters to customers is how much passengers are delayed compared to what they originally flew. That is an enormously difficult number to calculate in aggregate so I doubt if we will ever see it but that is really what matters and is the basis of your suggestion for EU 261 type compensation.
It is very likely that there were relatively few passengers out of the ones impacted that were at the gate waiting for the flight only to have it cancelled. Crew coverage cancellations usually happen several hours in advance and even the day before.
I am not interested in throwing stones but there was nonstop coverage from the media about UA’s EWR meltdown in the spring of 2025 as well as WN’s operational meltdown a couple years ago because there were massive numbers of people stranded at airports which made for ripe national news coverage. All airlines have had those types of mass meltdowns but this simply was not one of them no matter how much some people want to try and make it that way.
Regarding the pilots union, I don’t think there is a need to bash them but it is absolutely valid to note how extraordinarily complex their contracts are; there can’t be another group of highly paid workers anywhere in the world that have as much complexity in the rules around how they work and get paid. ARCOS is all about a way for DL to automate some of the notification and preference processes that DL and DALPA have already agreed to as part of their contract.
DL’s cancellation numbers are very low again so I suspect they have tweaked the program rather than throwing it out but there are endless debates between DL pilots about what types of rules are better – and the answer depends on each individual pilot.
As for the fighting between people, all I ever fight for – and always will – is for accuracy. When someone has to post manipulated statistics in order to be able to claim a win, then that should be called out and, as long as I participate in these discussion boards, I will.
I am more than capable of living w/ real, valid statistics regardless of what they say.
I look forward to a great 2026 and beyond and I esp. enjoy discussions w/ people that I agree w/ sometimes but disagree w/ at other times; life is not near as fun when you disagree or agree w/ anyone 100% of the time.
Happy travels to you and best to Gary and his family in 2026
@Tim Dunn — Always a pleasure.
(Also, super-cold and windy at JFK this morning. Feels like 5 degrees. At least the sun is out! And the de-icers are sprayin’!)
@Tim Dunn, as you pat yourself on the back for how much you value accuracy (questionable given how incorrect some of your statements in the past have been — happy to provide references if you want to discuss this further — but it’s safe to say that I don’t trust a word you say when it comes to legal issues or financial analysis), how much you’re not interested in throwing stones (an interesting assertion given some of the juvenile insults you flung at Gary in this vary thread) and how great you are at living with statistics (contradicted by the fact that you seemed to conflate 2024 with 2025 when throwing mud at United) — you have barfed up 629 additional words of comments and I still don’t see anywhere that you have pointed out anything that was incorrect in Gary’s original post. You’re getting close to 2,000 words in total.