How can I verify if an airline is telling the truth about the reason for the flight's delay, in the context of EU delay compensation?

Question

Today I've received the following email from Air France in regards to my request for compensation under EU flight delay rules:

We are really sorry to learn our flight AF379 delay on 15th August 2018 disrupted your travel plans. We understand that delays inconvenience our passengers, so we do all we can to limit them. However, we sometimes face extraordinary circumstances when Air Traffic Control delays a flight’s departure or arrival. These Air Traffic Control delays are beyond our control.

As you may be aware, compensation is laid down and paid in accordance with the EC regulation 261/2004. In line with this regulation - and our General Conditions of Carriage - I must respectfully decline your request for compensation on this occasion. I am sorry for any disappointment this may cause.

How can I verify if ATC is in fact the cause for the delay of my flight?

Answer 1

Looking at specific departures around the time of your flight, it appears that basically ALL flights around that time left delayed (certainly every one I checked was delayed by a similar amount as your flight), making it very likely that the delay was indeed caused by "ATC".

For much of the second half of August the Vancouver area was being affected by poor visibility caused by smoke from wildfires in the area. This was at times resulting in delays for operations at Vancouver Airport - although I have no proof that smoke was the cause at this particular time.

Unless you have specific knowledge of something otherwise (eg, the pilot made an announcement saying they were doing maintenance on the plane) then I suspect you'll have no chance of proving that this was anything other than an ATC delay.