Does the response United provided to my compensation claim with the Canadian Transportation Agency really is a good justification for cancelling my flight, causing me to arrive almost 24h later than expected? What should I respond to them? Specifically, I have some questions about the ATCSCC messages:

  • Did they just cherry-picked some messages that could have been voided later on? Is there an archive somewhere of those messages so that I can find what came before, and after?
  • I noticed YQB is not mentioned in any of the advisories, so do they really apply? Is YQB included in another abbreviation?

For what it is worth, people in Quebec at that time told me the weather was fine. I thought I could provide a list of arrivals still happening at YQB at that time as a justification. Is there an archive somewhere for this sort of information? flightstats.com does seem to provide just that, but their terms and conditions forbid using their service for travellers' claim.


On February 27, 2023, I was scheduled on UA3463 from EWR to YQB. I had a long layover in Newark. To my surprise, at one point when walking to go to the bathroom, I noticed on a billboard that my flight has been cancelled. I was surprised because I would have expected some sort of notification from them, I gave them my email, phone number and I had United app installed after all.

At the United kiosk, they told me that the next flight to Quebec, in 12h, was full already, and that no other route was available either, so they scheduled me on the same flight, 24h later. They also put me on a waiting list for the next flight. I managed to negotiate a hotel room for the night, and they gave me some food coupons, but not enough, so I had to submit insurance claims. I inquired about the cancellation's reason, and they told me "air traffic control".

Up until the next morning, I would frequently refresh the app to see if I would move off the waiting list. It didn't. However, I woke up at 3am, and to my surprise, even if I was still on the waiting list, I was able to find the next flight to YQB in United alternative routes search engine, and book myself on it.

Canadian travellers are now supposed to be protected against unfair cancellations [4], and I didn't really trust the reason the agent at the airport told me, so arrived at home, I contacted United. This time, they said it's because of weather reasons. Given it was not the same reason, and they did not provide a proof, I was even less confident about their justification, and I opened a claim with the Canadian Transportation Agency (CTA). Below is United's response to my claim:

To Whom It May Concern, Our records indicate that UA3463 from Newark to Quebec City was canceled due to weather and air traffic problems on the eastern part of Canada on February 27, 2023. We generally do not provide physical proof of our flight disruption directly to the passengers; however, as requested, I have attached a copy of our United's flight information that is reported to the FAA. I have also included the FAA weather and air traffic delay programs that were in place that day. As is standard operating procedure, Mr. NAME was rebooked on the next available flight to his destination. We do support our earlier position and response to Mr. NAME that the irregular operation was due to extraordinary circumstances that could not have been reasonably predicted or avoided. Your understanding is appreciated. Best Regards, Katherine Dawson Customer Care - Case XXXXXXX

They attached these pictures to their response: First picture attached to United's response Second picture attached to United's response Third picture attached to United's response


Thank you

  • 3
    ATC reasons are not in their control Commented Jan 8 at 16:36
  • I know, but I'm not knowledgeable enough about the system to assess whether there really was a valid ATC reason here. For instance, the fact that YQB is not listed in "CONSTRAINED FACILITIES" or "DEP SCOPE".
    – user141919
    Commented Jan 8 at 16:47
  • Sadly it is frequent that some greedy airlines will try to lie out not to give comp. There are some take-a-cut-of-the-winnings law firms that may be able to battle that if you want Commented Jan 8 at 18:17
  • 1
    The codes in dep scope are not IATA airport codes. You may be able to get a better answer on the meaning of those advisories (rather than whether the cancellation was justified) on aviation.stackexchange.com
    – jcaron
    Commented Jan 8 at 20:55
  • In the US, bad weather in Chicago will delay operations at O'Hare airport (ORD). Because ORD is a key hub through which significant amounts of air traffic travels, delays there could delay flights between Houston, TX and Miami, FL because a flight could be delayed in ORD on its way to IAH, thus delaying that plane's flight to MIA. This could easily be the reason for your delay, even though the weather at your departure and destination locations were just fine.
    – FreeMan
    Commented Jan 9 at 16:32

2 Answers 2


Your initial concern seems to be around the first you were first told the reason for the delay was "weather" and then subsequently told it was "ATC". In truth, it was likely both of these things, as they are tightly intertwined.

In good weather conditions, an airport might be able to handle 60 flight arrivals and 60 flight departures per hour. There might be 45 flights scheduled to arrive at that airport each hour.

As the weather turns bad, this number will change. Conditions might mean that the airport is unable to use all of it's runways. Or there might be a need to increase the separation between flight when landing or on take-off. Or winds might dictate that take-offs and landings have to use the same runways instead of having separate runways as they normally do. When this happens, ATC will reduce the allowed arrival and departure rates - lets say down to 30 of each per hour.

If this weather is short-lived, then the airport/airlines may be able to recover from this. If there's one hour of reduced movements, then they go back to normal, then after 2 hours they will be able to handle all aircraft - some with delays, but they will all be able to land/take-off.

However as the weather continues, airlines will have to start cancelling flight. Who is to blame for those cancelation? Technically, it's ATC. ATC will not give the airline approval for the flights to depart their origin airport, so the delays are due to ATC. But at the same time, the reason ATC is causing the cancelation is because of the weather. So in this case, both 'ATC' and 'Weather' are valid excuses for the cancelation - as they are both the true!

In many (most) cases it's actually the airline that makes the decision which flight(s) to cancel. eg, an airline might have 6 flights scheduled to fly into the airport above. ATC will tell them they are only allowed fly 4 - without generally dictating which ones. The airline will then decide which 2 flights to cancel - which is one of the reasons that it's often smaller aircraft like the one you were on that get cancelled, as the overall impact of doing so is smaller than if they had cancelled a larger aircraft.

If you look at the text in the screenshot they have sent you, it is "WX/ATC-UA INITIATED". WX is Weather. ATC is obviously ATC. "UA INITIATED" most likely means that UA actually made the decision to cancel the flight. This matches what I've described above - due to Weather(WX), ATC initiated arrival constraints which required the airline to cancel at least one flight. United made the decision to cancel THIS flight, in response to those ATC instructions.

Having said all that, I can't find any indication that there were weather/ATC delays for YQB on that day, however there were significant delays - including an almost 2 hour complete "ground-stop" - at YYZ (Toronto). It's possible your flight was actually canceled due to the aircraft (or crew) being stuck in Toronto from a previous flight. It's not clear to be if that would be considered a covered delay under the Canadian rules or not!

  • For reference, in the EU and other places covered by EC261 or its clones, the airline could not claim extraordinary circumstances for weather/ATC if it wasn’t the flight itself which was directly affected, but a previous flight using the same aircraft or crew. No idea what the rules are in Canada (didn’t even know Canada had any protections in this case).
    – jcaron
    Commented Jan 9 at 21:59
  • Canada's law is similar in spirit to EC261, but much weaker, sadly. Thankfully, there has been a revision in August of last year that explicitly puts the burden of proof on the transporter. Although it's hard for me to prove that the event was outside of United's control after so long, and without their data, I believe that by taking elements from your response, I should be able to show that United's response is not sufficient to explain that it was outside their control. Thanks a lot.
    – user141919
    Commented Jan 10 at 17:19


It looks like there was a ground stop of over an hour in Toronto plus a whole lot of ground delays. I'm guessing that the aircraft for your flight was coming in from Toronto and got stuck there. Unfortunately this was almost a year ago and that would be difficult to get details now.

This is a borderline case. Most likely the plane was indeed blocked by a weather related ground stop in Toronto but that ground stop wasn't in any of the cities you booked your flight from or to. So United is arguing "The scheduled plane was grounded by an ATC ground stop so we couldn't fly". You are arguing: "I booked a flight from Newark to Quebec, why the heck should I care where there is a ground stop somewhere else. EWR is a major United hub, you should have just used a different plane"

How the CTA will rule this is anyone's guess.

The control stop was clearly "outside the control" of the airline, so they are off the hook for the flight from YYZ to EWR. However, whether finding an alternative aircraft and/or crew for the subsequent flights scheduled with the same aircraft can be considered "reasonable" is for the CTA to decide.

  • This is very useful., thank you. I basically went for "I booked a flight from Newark to Quebec, why the heck should I care where there is a ground stop somewhere else. EWR is a major United hub, you should have just used a different plane", as my argument. Hopefully, the CTA will rule in my favour.
    – user141919
    Commented Jan 10 at 17:21

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