While we don’t have the data, I have to assume very few passengers misconnect in a given day due to things in deltas control or else they’d change how they’re booking connections, etc.

Yes, agreed - missed connections don't cost Delta much other than CSAT. Which is why I have a bugaboo about it. I am pulling this number out of my rear end, but probably only 2-3% or so of flights (or about 10-15% of delayed flights) are going to be tagged as "Delta's fault" (maintenance, non-WX crew issues, etc) and so the vast majority of misconnects from delays are going to be at the passenger's expense, not Delta's.

Similarly, people who buy a 36 minute connecting ticket, and the inbound flight arrives exactly on time, and the passenger gets off the plane as quickly as possible, and gets to the gate as quickly as possible (brisk walk, no bathroom, etc), and still misconnects due to an unreasonably short MCT and early gate closure.. will be claimed not to be Delta's fault and therefore they have no obligation to do anything for the passenger.

Indeed, a strict reading of the contract of carriage would actually imply that Delta is not even obligated to rebook them on another flight because Delta has fulfilled its obligations and it is the passenger who "technically" failed to meet them. Obviously they will, but they will almost certainly not receive accommodations for overnight stays or other compensation even though Delta knew at the time they sold the ticket that the passenger would likely not make the connection.

Excessively short MCTs are arguably a form of bait and switch: selling tickets to passengers that Delta may reasonably know are not likely to be flyable by a passenger.

edited to add: when costs are switched from passengers to the airlines, there is evidence that airlines change MCT to be more realistic. MCT has gone up at multiple airports in Europe (I know for sure at MUC, LHR, AMS) since EC261 was implemented. While not conclusive, this is strongly indicative that excessively short MCTs may be exploitative in some cases.

Was that the last flight of the day, that is the only time I normally see them holding for connections. I have had them hold a plane for my family and I, a total of 6, but it was 5 -10 minutes and with weather delays the day prior all flights were sold out for the next two days.

Delta has the data and we do not, but I would be extremely surprised if even 50% of tickets at MCT result in misconnections. As a pax it's easy to focus on the fear and stress of a missed connection where even a 20% chance can feel like a "big deal". But Delta is setting MCT based on large-scale data and I think it is going way overboard to call it a "bait and switch". For every mobility-impaired pax in the last row a 753 that blocks in 0h14 late (meeting A15) that needs to change terminals in ATL, there are able-bodied pax in the front half of the plane who arrived 9 minutes early with a shorter walk.

Last time I had a 0h35 connection in DTW it was something like B10 to A75 and I had time to snack in the SkyClub.

A lot of this thread focuses on pax booking risky connections and being partially to blame. But remember if you book something more than two months out, most of the time Delta changes the schedule on one or both flights. You can book an hour connection at SLC and by the time you fly it’s scheduled at 32 minutes.

And DL allows you a free schedule change.

I wonder how this thread would go if DL routinely held flights — if people would complain about being late or delayed due to this. I suspect yes.

My point is being made in conjunction with doors, as a matter of policy, being closed earlier than needed at hubs combined with short MCT. Doors are regularly closed early now at hubs at a rate that, at least in my sample size, are greater than they were in the past (pre-COVID). The boarding door is closed at T-12 and then the plane pushes back 5 minutes late because they were waiting on bags or otherwise had a delayed sort of flight. This is a regular event now.

I do think it is fair to call it "bait and switch" if part of Delta's decision matrix is the fact that they know the vast, vast majority of misconnect costs are borne by the passenger and not the airline. If the inbound plane arrives on-time (as defined by A14) but the passenger misconnects, all costs associated with that misconnect is on the passenger (and of course most delayed inbound flights are due to a force majure so even if the inbound is late most of the costs are still borne by the passenger). Outside of potential customer service agent time, I don't consider rebooking having any material cost to Delta as very, very few tickets are bought "day of" these days and so there is no real lost revenue (the strongest argument here would be the need to lower realized load factors to account for misconnects but that is a stretch).

Delta's "large scale dataset" associates a cost to Delta from misconnects. But that is only a fraction of the cost borne by a passenger. Again, the fact that MCTs went up at multiple European airports in the years after EC261 implies (where delays over 3 hours - regardless of fault - entitle the passenger to accommodations / food / etc when needed) that when the costs of misconnects are internalized to airlines (not even including lost time of the passenger - that is still borne by passengers), airlines adjust to reduce misconnects.

I know the response to this will be "caveat emptor", but to the extent possible, markets operate most efficiently when there are not information asymmetries between buyers and sellers. Lower-information buyers (which at least by count far outweigh high information frequent flyer buyers) are least likely to understand the nuances of tight connections and won't inherently understand the implications of missed connections in terms of having the cost of a misconnect fully externalized to them as the passenger.

If the US had EC261-style rules, I wouldn't be on my soap box about this. But so long as airlines get to externalize cost of misconnects to passengers while simultaneously making it more difficult to connect through early door closure unrelated to non-trivial exigent operational constraints, I'm going to complain about selling unreasonably short MCTs. The fact that veteran, high-information travelers almost all agree that you shouldn't buy tickets at MCT but add additional buffer is further evidence at the fact that MCTs are set too short. High information buyers avoid them, while lower information buyers buy them expecting that airlines wouldn't sell tickets with connections that will lead to a very high misconnect rate.

I'm not even sure what to make of this. YOU started the thread, if you are upset about "risky" connections then you can, as you have already noted, book longer connections. If your schedule changes Delta will let you rebook. "A lot of this thread focuses on" things that are completely under your own control.

hold up, this is a conclusion that I do not believe is supported by evidence.

Does DL sometimes close the door early? Yes, absolutely. Do people sometimes misconnect? Yes, absolutely.

What's missing is evidence that any of those misconnects are caused by closing the door early. Closing the door at T-12 is not closing the door early.

I don't think it is 1/10th of that. But that is a guess too.

yes I would guess it's way closer to 5% than 50%. Probably less than 5%.

I'm going to guess you live in a big city where you don't often have to connect or have lots of frequency to lots of different hubs. I live in a small market with a few airlines with service to a few hubs. We are at the mercy of the schedule. I hate booking 30 minute connections but sometimes that is the only option, especially when Delta won't sell a domestic connection longer than 4 hours. Delta makes the schedule, Delta changes the schedule and Delta decides what connections are legal. Delta decides when to close the door and Delta decides when to hold for connecting pax. But people here like to blame the passenger.

There is a direct correlation between time of door closure and number of misconnects. Every minute you wait you can catch more people. I believe United's software takes into account all the connections and recommends a specific time for door closure and/or specific passengers to wait for and who not to wait for.

At a hub and in context of a 35 minute MCT, it is. Yes, I know what the contract of carriage says: domestic flights doors can close at T-15. But that is incompatible with a 30 or 35 minute MCT in a fleet increasingly comprised of large narrowbody aircraft. This is my point of contention.



So you believe the misconnect rate for tickets booked at MCT is less than 5%? Despite the fact that A14 performance was only 84%? Obviously there are instances where the connecting flight is delayed as well and the passenger makes it onto the flight, but a 5% misconnect rate at MCT is absolutely laughable. It would be relatively rare that someone makes a connecting flight at MCT when their inbound was even just 15 minutes late (the earliest possible arrival time for the 16% of delayed flights).

It would mean some combination of at least three of following has to be true: 1) ground ops was fast at getting the boarding door open [arrival time is when the parking brake it set]; 2) the passenger is at or near the front of the plane; 3) the boarding door on an on-time connecting flight was not closed until T-5 or later; 4) the inbound/outbound flight gates were in the same concourse; 5) the outbound flight was delayed

Delta's A0 performance is around 60-65%. So long as passengers are in the front half of the plane, I would expect the majority of those passengers to make their connections unless Delta closed the gate of the next flight right at T-15 (which is still rare, at least at Atlanta). But if you're in the back half of the plane, it gets riskier even for flights that achieve A0. The approximately 20% of flights that are A1-A14 will probably lead to misconnects more often than not for passengers in the back half of the plane unless Delta leaves the gate open for the outbound flight until at least T-5.

Delta's Atlanta MCT has been 35 minutes since E opened, and I believe that it was Delta's MCT back in 1990 even before E opened (but I can't find an explicit source for that)*. While domestic flights into/out of F are somewhat rare, it is common in E. During that same time, the average seats on a mainline Delta plane has gone up by 30-40% while average load factors have gone up from about 75% to around 90% (meaning longer deplaning times). And while I don't have access to Delta's internal data, it does appear there is a recent trend to push gate agents to close the boarding door earlier than they used to whenever possible.

Someone is paying a price for that, and most of it is being paid by consumers buying tickets that can reasonably be expected to lead to misconnects.

* best I could find was old flight tables from the early 90s where a quick skim didn't show any valid connections less than 35 minutes but I did not find an authoritative MCT document

ok, I get it. if you're going to do this every time someone has a different preference from you we're never going to have a productive discussion. thanks.