Why do flights get canceled?

SixPapaCharlie

SixPapaCharlie

May the force be with you
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Aug 8, 2013
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First Officer 6PC
As an insider now, I’m still no more knowledgeable about why flights get canceled than I was a year ago.

My wife had a trip to Philly yesterday and I was excited for her. It was on a Dreamliner, which is an experience.
She was at the gate with about 30 crewmembers deadheading to PHL. The plane was there, the pilots were there, and then boom! Canceled.

Everyone got bumped to the next flight, and then the next, until eventually all of them were canceled by the end of the day.

I’ve seen cancellations from pilot timeouts and maintenance issues.
But when I checked my company app, about 75% of the flights (literally hundreds) were listed as canceled.

Some flights did make it from DFW to PHL, and there wasn’t any weather between here and there. The only thing I can speculate is a bandwidth issue.

On Sunday I flew a Sioux Falls turn while most other flights were canceled.
We had long de-ice delays (1.5 hour taxi plus de-ice) and only one runway open at DFW, so the only explanation I can come up with is simply not enough capacity to move planes in and out of the airport?
 
And if the plane can’t get to DFW, the scheduled flight out of DFW gets canceled…it can get to be a vicious cycle.

Unfortunately the passengers often don’t get the truth… “the weather in Wichita is bad.” “Um, all of Kansas is clear.” “Well, there’s fog between here and there, and they can’t fly in fog.”
 
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MauleSkinner said:
And if the plane can’t get to DFW, the scheduled flight out of DFW gets canceled…it can get to be a vicious cycle.

Unfortunately the passengers often don’t get the truth… “the weather in Wichita is bad.” “Um, all of Kansas is clear.” “Well, there’s fog between here and there, and they can’t fly in fog.”
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Which is odd because we have a ton of outbound flights where the inbound is late / delayed and those inbound pax miss the connection and we keep on truckin.
If it is cancelled for maintenance or because I overslept, I am in the know. If it just is on the schedule and then flips to cancelled while the pilots and plane are at the gate, it is a mystery. To me anyway. I drove my wife to the airport in the morning and spend all day trying to connect any combination of flights to get her there but ended up driving back to retrieve her at the end of the day.
 
Welcome to IROPS.


ETA: in GA, we have these things known as hangar fairies; they do stuff to the plane when the owner and maintainers aren’t around, sometimes with unintended consequences.

In the airline world, you have schedule fairies. They do the same thing, just with the daily flight ops schedule.
 
If a plane can't leave for whatever reason, there's room for one less incoming plane, so that incoming plane is now stuck at its origin causing trouble there, and...

The system can absorb a certain number of delays or cancellations, but if enough flights get affected it throws everything out of whack. And if the weather delay is at a hub it's even worse.
 
What bothers me more is when you buy a ticket two months in advance and pay a premium price based on schedule or number of layovers and then the airline then changes the flight by hours or adds additional stops just a week before flying. They will offer a refund but what good does that do if you now need to buy a last minute ticket at an inflated price. It seems to be happening more and more often over the past two years. I understand weather or maintenance issues the day of flight but if you are going to sell me a flight and that price is directly tied to the flight times or number of layovers then there should be some sort of compensation to the passengers when the airline just decideds to change its scheduled flights.
 
I thought about this answer for a while. The best I can come up with is “its complicated”.

Find somebody to escort you into the operations center for a look at the team that keep scheduling under control. While you’re there consider what happens when 10 extra jets go out of service or the weather ground stops Charlotte for two hours. I think it would be great background knowledge for your channel.

I’ve said here before that I think it’s a miracle that things generally run as well as they do.
 
It's often not obvious, but there is a reason. It's just a "big picture" reason that has more to do with system integrity than the specifics of the cancelled flight.

Normally, a hub-to-hub flight would be protected, especially when it's a widebody that can help clear out the backlog of displaced passengers.

Look to see what they airplane was reassigned to do. It may have been needed to protect a higher-priority flight, such as a once-per-day international flight.

Look to see the situation at PHL. The hub may have had significant restrictions to its arrival rate and choices had to be made as to what to cancel and what to operate. Our EWR and IAD hubs were hit hard so probably PHL, too. EWR was completely closed for some time.

In IROPS, it's all about using the available assets (gates, planes, crew, etc.) to do the most overall good.
 
Drove an hour on the ice today. As soon as I got out of my car at the airport, they cancelled my flight.

Just snagged a trip from a reserve FO but that's probably getting cancelled too.
 
Larry in TN said:
Look to see what the airplane was reassigned to do.
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Exactly.
Wherever the aircraft ultimately flew was a higher-priority use of company’s resources.

… and as an aside, (somewhat related), but if mainline needs the slot, RJ gets cancelled/delayed.
 
I will admit, I have no idea how airline ops centers keep it straight even on a good day. Tracking aircraft schedules, crew schedules, maintenance requirements, crew rest requirements, gate availability, etc, etc. Then you have a plane have a break down, or a weather event even delay a flight, and the best laid plans are shot to hell. Just this last week ORD went into a ground stop because a pipe burst in one of their control towers.
 
I was asking this same question 3 weeks ago in Amsterdam, Tuesday AM flight home was cancelled, nobody getting out, trains even cancelled. Eventually rescheduled for a Friday AM flight.
Monday was grey with wintery-mix off an on, but it's not like the airport should have been closed all day...it came an went. A few flights I'd understand, but this was a mess! Through the week there were a couple of other short windows of time when the vis and ceiling dropped with some precip
But there were a whole lot of hours through the week with blue skies
There was like 2 inches of snow on the ground and the roads were very drivable, totally clear most of the time.
I just couldn't add it up!
 
Dana said:
If a plane can't leave for whatever reason, there's room for one less incoming plane, so that incoming plane is now stuck at its origin causing trouble there, and...

The system can absorb a certain number of delays or cancellations, but if enough flights get affected it throws everything out of whack. And if the weather delay is at a hub it's even worse.
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Yep…. It’s called the spoke and hub system. Worst thing that every happened to the airline industry. Go read some of the books and articles/research on airline deregulation and how the spoke and hub system came to be. What a cluster!
 
I’m curious to know how many are cancelled by an actual person making the decision vs. a computer just spitting it out.
 
If it was American, they had a meltdown and lost track of their flight attendants. Additionally, they changed their hotel provider who no longer allows pilots to schedule rooms during IROPS. Consequently, their pilots don't have the required rest.

And scheduling had no idea about it until people showed up and said "I'm not legal" or just didn't show at all because they were stuck in another town.
 
midwestpa24 said:
I will admit, I have no idea how airline ops centers keep it straight even on a good day.
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With a whole lot of computer screens. This is just one small corner of UA's NOC.
united-1.jpeg


Rcmutz said:
Yep…. It’s called the spoke and hub system. Worst thing that every happened to the airline industry.
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Hub and spoke is what allows you to go from anywhere, to anywhere, with just one, sometimes two, connections.
 
Larry in TN said:
Look to see what they airplane was reassigned to do. It may have been needed to protect a higher-priority flight, such as a once-per-day international flight.
Click to expand...

A few months ago we had a flight from Hawaii to Seattle (Alaska Airlines). The Seattle flight before ours had a mechanical failure, so they took our plane (they were delayed a couple hours). There was a flight that was supposed to leave after us to San Francisco, we took their plane leaving a couple hours late and the San Fran flight was canceled. Our guess was Seattle being a hub, a lot more missed connections would have cost the company a lot more than having people stranded in Hawaii an extra night. It was kinda interesting watching how they dealt with the limited flights they had.

Tim
 
Larry in TN said:
With a whole lot of computer screens. This is just one small corner of UA's NOC.
View attachment 149392



Hub and spoke is what allows you to go from anywhere, to anywhere, with just one, sometimes two, connections.
Click to expand...
The airlines could go off gone with a point to point model utilizing smaller aircraft. Boeing actually looked at that model about 10 years back but decided not to pursue. Air Mobility using EVtol May just reshape the entire airline transportation model in the next 5-10 years.
 
Larry in TN said:
It's often not obvious, but there is a reason. It's just a "big picture" reason that has more to do with system integrity than the specifics of the cancelled flight.

Normally, a hub-to-hub flight would be protected, especially when it's a widebody that can help clear out the backlog of displaced passengers.

Look to see what they airplane was reassigned to do. It may have been needed to protect a higher-priority flight, such as a once-per-day international flight.

Look to see the situation at PHL. The hub may have had significant restrictions to its arrival rate and choices had to be made as to what to cancel and what to operate. Our EWR and IAD hubs were hit hard so probably PHL, too. EWR was completely closed for some time.

In IROPS, it's all about using the available assets (gates, planes, crew, etc.) to do the most overall good.
Click to expand...

This

I don't even begin to understand it, as a pilot at a different major. I just go where they tell me, and normally don't predict really well, what curveballs might be thrown at me on a given trip.
 
My outsider's view guess, stress guess, is that the typical airline has a system that barely works on normal days, and doesn't have much redundancy in terms of staff anywhere, and the schedules are both highly optimized for economic efficiency and is setup so that only certain aircraft can fly certain routes. Or in other words, not much redundancy from an operational perspective, so it's a perfect setup for a cascade failure. When one thing breaks, it spreads a bit like a chain reaction.

For the 10% on here that aren't geeks - https://en.wikipedia.org/wiki/Cascading_failure

Huh...looks like somebody looked into this already:

First part is in Spanish but it goes into English. Not directly about weather but it's similar.

Short version - the system barely works on a good day, so it's easy to tip over.
 
When you move over to the legacy side of the fence you can call and ask. After you do that once or twice it becomes apparent the reason is irrelevant. Then you won’t care.
 
I think @Albany Tom raises an interesting point about capacity.
Airlines are very capital intensive, highly regulated/contracted companies operating with very small margins. Excess capacity costs firms money.
Therefore the companies are incentivized by simple market and economic factors to run as close to possible to 100% on a fair weather day. If you search around the web, you will find the airlines across the complete system in the USA run in the low 80s for Passenger Load Factor (PLF). PLF covers all flights except dedicated cargo flights, even night ferry flights would be included. That does not leave much capacity in the system to handle widespread events.

Furthermore, the more aircraft types, the more complex recovery can become. I forget which airline, but there was an operational meltdown within the last few years (computer system related if I recall correctly). There were news stories about how it took the airline a full day of flying mostly empty flights to reposition equipment and crews to restore operations; with it taking close to a week to get crews fully back to the normal schedule. (For some reason I want to saw SWA, but not sure it was them.)

Tim
 
A staggering number of events need to take place for a day's schedule to go as planned. That makes it improbable in the big airline world. A plane might be scheduled for 5 flights over the course of a day. That's a lot of opportunity for something unforeseen to happen. Those flights might depend on six crewmembers being in the right place, the weather being adequate.
As stated earlier, it's a marvel that it works as well as it does. Over the course of a career, you'll experience some days when nothing seems to go right. Lots of problems to deal with, decisions to be made. That's why we get paid. Past tense for me. Not many boring days. Well....training.
 
kmacht said:
What bothers me more is when you buy a ticket two months in advance and pay a premium price based on schedule or number of layovers and then the airline then changes the flight by hours or adds additional stops just a week before flying. They will offer a refund but what good does that do if you now need to buy a last minute ticket at an inflated price. It seems to be happening more and more often over the past two years. I understand weather or maintenance issues the day of flight but if you are going to sell me a flight and that price is directly tied to the flight times or number of layovers then there should be some sort of compensation to the passengers when the airline just decideds to change its scheduled flights.
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Bait and switch is alive and well...
 
Brad W said:
I was asking this same question 3 weeks ago in Amsterdam,
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The de-ice program in AMS is a train wreck. They are terribly slow and very formal on the scheduling of the order of de-ice. It's the longest I've ever waited (~2 hours at the gate ready to push) with the least number of airplanes in front of us (less than 7).
 
Perhaps a smoke break between planes, then a couple of chocolate bars and a nap.
 
tspear said:
Our guess was Seattle being a hub, a lot more missed connections would have cost the company a lot more than having people stranded in Hawaii an extra night. It was kinda interesting watching how they dealt with the limited flights they had.
Click to expand...
They look at the option that makes it easiest to recover. To get as many passengers as possible to their destinations as quickly as possible and how to return their resources, aircraft and crew, to where they are supposed to be as quickly as possible. That leads to international flights being prioritized, last flights of the day, flights that move more passengers (bigger airplanes) over those than move fewer. etc.

Rcmutz said:
The airlines could go off gone with a point to point model utilizing smaller aircraft.
Click to expand...
We have point-to-point airlines. Southwest was the biggest, but they've largely given up that model. Allegiant is probably the biggest of the strictly point-to-points. Also Spirit, Frontier, Breeze, and Avelo. They work great, if you want to go where they go from where you are.

Almost 15 years ago I would travel from my home in Nashville to Bahrain. How would that work without hub-and-spoke? If I'm the only person going from BNA to BAH today, do I get my own airplane?

There will always be some point-to-point service, but you can't build a comprehensive route network without hubs.

Albany Tom said:
the typical airline has a system that barely works on normal days, and doesn't have much redundancy in terms of staff anywhere, an
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It's not that the system barely works, it's that the system is near capacity. As far as staffing, I still wonder where the army of deicers and snow removal staff come from when a storm comes through. What are they doing on nice weather days?

There are very few weather days that would significantly delay a flight if it were the only flight operating. Weather's role in delays is that is decreases overall system capacity.

When an airport, or area, is hit with bad weather, capacity can be cut 80% or 90%. You can't run our airports at 10% on good days so that they will be able to keep up on bad days. Building out that much infrastructure would be too expensive and wasteful.

Today, our airports and ATC infrastructure is behind demand. Almost every airport has ongoing expansion projects underway or being planned. Aircraft manufacturers have not been able to keep up with airline demand as airlines are trying to keep up with public demand. None of this will be fixed quickly, barring a big recession, and even that would only be temporary.

At my airline, they keep something called a Flight Feed. It is a log of all events that happen as a flight is being prepared, from the assignment of the aircraft and gate through the arrival at the destination. A completed flight will have dozens of entries in the feed. It is rare for a flight to operate without numerous problems showing up in the feed. In most cases, those problems are solved and the flight operates as scheduled. A delayed flight might have a dozen problems, all contributing to the ultimate delay. There is a communication log, called the chat, where to zone controller, pilots, gate agent, inflight manager, and flight attendants can all communicate. Missing catering, late fuel truck, broken tray table, duplicate seat, disruptive passenger, missing or opened infection control kit, etc. All sorts of things are discussed and dealt with, even on on-time flights. Operating an airline flight is a complex endeavor. It is resilient, to a point.

The question is, how much more resilient can it be made at a cost that the traveling public is willing to bear?
 
Larry in TN said:
The question is, how much more resilient can it be made at a cost that the traveling public is willing to bear?
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As long as someone else pays, the traveling public is all for as much redundancy as possible.

Tim
 
AV8R_87 said:
View attachment 149414
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I had one of those! Except it was the Heathkit version, H-19 terminal I think was the model. It was very fast for the time - 19.2k baud, and 80 characters with an anti-reflective green screen. The screen was actually easier on the eyes than anything today, as it was etched matte glass so it wouldn't have as much glare.

Anyway, I can't speak for anyone else but I wasn't suggesting that adding capacity or redundancy should be done to improve reliability of scheduling. To me, it's just fine because it works just fine most of the time. And while I don't know the cause, just guessing there, I'm pretty sure that improving scheduling reliability would cost a decent amount of money. Even if it's just upgrading ANSI terminals.
 
In almost 5000000 miles of flying on various Airlines, both current and defunct, the strangest cancellation I ever experienced happened Tuesday.

GF and I were scheduled to fly AA from HDN (Steamboat Springs) - DFW. AA schedules a 737 Max out and back once a day from DFW. The flight was continuously delayed and finally canceled. Then eventually the 737 was flown EMPTY to HDN later in the day, overnighted and flown back to DFW EMPTY again canceling both the inbound leg and outbound leg for that day’s flights.

All the while this was going on, I get various message from AA stating anything from, your flight is delayed, canceled, flying tomorrow morning, to my connection is good even though it leaves DFW before we would get there.

The ground staff was also mystified since they were getting similar conflicting info from ops, FAA and who knows what sources.

The comment about the FUBAR on Cabin Crew may have been the underlying cause coupled with weather at DFW. But burning up 6 hours worth of Jet A with zero income is a pretty price to pay for overnight parking. :biggrin:
 
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Strangest flight change I had was a flight from Boston to Tenerife (Spanish Canary Islands) via Portugal.
At the time of booking, TAP had one flight a day to Boston. And two flights a day to Tenerife, one in the morning and one in the early afternoon. When we booked the flight, we were flying out Saturday night from Boston, landing super early Sunday in Portugal and taking the Sunday morning flight to Tenerife. Coming back, Saturday afternoon flight to Portugal, and evening flight back to Boston landing very late Saturday night in Boston. Seems pretty reasonable.

TAP Schedule change, one flight a day in the late evening between Portugal and Tenerife only; and Saturday Boston to Portugal flights canceled. So, TAP on the outbound put us on the Sunday flight from Boston to Portugal, and rescheduled us from Portugal to Tenerife on Saturday evening. For the return, they switched us to a Sunday evening flight from Tenerife to Portugal which departed Tenerife after the Boston flight left Portugal.
Customer service did not see an issue with this. Had to escalate to a supervisor who understands that airplanes cannot go backwards in time.

Tim
 
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