I took the Princess to London last year for her birthday in April. The flight we were due to take was cancelled and we had to get a later one. At the time, I thought it was the air traffic controllers’ strike in Paris, certainly, no alternative explanation was offered.

So, I complained to British Airways that I couldn’t understand why a strike in Paris should affect flights between Dublin and London. And they wrote back to me and said the EU regulations did not entitle me to compensation but little else.

I was peeved. I wrote to the Irish Commission for Aviation Regulation. Bonus information, they confirmed you can get compensation under EU regulations if you are flying on frequent flyer miles. They took a long time to fully address my concerns but last week I received this outstanding letter. Alas, I am not entitled to compensation. It turns out there was fog in London. It was a pity BA hadn’t mentioned this at any time previously as they then would not have had to deal with my complaint. But it’s almost worth it, for this very full explanation of what happened.

Enforcement of Air Passenger Rights under Regulation (EC) 261/2004 establishing Common Rules on Compensation and Assistance to Passengers in the event of Denied Boarding, Cancellation, or Long Delay of Flights

Re: Cancellation to British Airways flight

I refer to the above matter which has been ongoing for some time now. Please accept my sincere apologies for the delay in updating you in relation to this matter. Our investigations into your complaint took much longer than usual. You will be pleased to note however that we are now in a position to conclude on this matter.

Your complaint relates to the cancellation of British Airways flight BA829 from Dublin to London Heathrow on the 9th April 2015. As you are no doubt aware, Article 5(3) of Regulation 261 states that an “…operating air carrier shall not be obliged to pay compensation in accordance with Article 7, if it can prove that the cancellation is caused by extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken”.

In response to our investigation British Airways contended that the exemption contained in Article 5(3) applied to the cancellation of flight BA829 on the 9th April 2015. They forwarded detailed correspondence for our attention in support of this contention. British Airways advise us that Flight BA829 was cancelled on the 9th April 2015 as a result of fog at London Heathrow airport which resulted in Air Traffic Control at the airport placing restrictions on the numbers of departing and arriving aircraft throughout the day in question. The air carrier explain that this resulted in the number of aircraft movements at the airport falling as low as 36-40 per hour during the day instead of the usual 45-47 per hour. British Airways state that delays quickly developed and knock-on delays built up as the morning progressed.

As a result of the restrictions, the air carrier advised that they were forced to reassess their operations at London Heathrow for the remainder of the day. Failure to do so would lead to further disruption as cabin crew run out of legal operating hours, and aircraft are unable to reach their planned destinations before the night closure of London Heathrow airport.

The airline further explained the practical effect of these ATC restrictions is that majority of the reduced landing capacity at Heathrow is taken up by arriving longhaul aircraft – most, if not all shorthaul aircraft is held on the ground while awaiting their ATC allocated take-off slot. These delays can typically be between one and two hours per flight. In your case the aircraft scheduled to operate your flight was due to operate a number of flights into and out of Heathrow prior to BA829. The airline identified your flight as one of 10 pairs of short haul flights which would have suffered knock on delays and been restricted to the extent that they would not have had time to operate before the airport closed.

Therefore the decision was made to cancel these 10 pairs of flights as operations knew that all flights could not then depart as there would not be sufficient slots at London Heathrow airport.

During our most recent ‘case meeting’ the very detailed documentation supplied by the air carrier was examined by the Air Passenger Rights (APR) Team at the CAR and your case was discussed in detail in the context of the Regulation and any relevant case law.

Following that discussion, the APR team concluded that the air carrier had demonstrated the existence of adverse weather conditions at London Heathrow airport on the day in question and has also demonstrated that restrictions were imposed by ATC on both inbound and outbound flights for the remainder of the day as capacity was limited. In this regard, we recognise that recital 15 of the preamble to Regulation EC261 specifically cites instances where the impact of an air traffic management decision gives rise to a long delay at either the airport of arrival or departure as constituting ‘extraordinary circumstances’ for the purposes of article 5.3.

In relation to the reasonable measures taken to avoid the cancellation, British Airways inform us that during times of partial disruption (i.e. restricted ATC flow rates all day but not severe disruption) when there are insufficient slots available at London Heathrow to operate the planned schedule in full, their operations department engage with various other departments within the airline to work out which flights need to be cancelled in order to create some slack in the aircraft and crew schedules to absorb rolling rotational delays, have the minimal impact on customers by choosing flights where passengers can be re-accommodated on other flights most easily and mitigate the risk of last minute cancellations, particularly where this might be caused by a late arrival at night infringing the night jet ban.

In this case British Airways explain that using these criteria BA830 from London Heathrow to Dublin and the return BA829 were selected amongst 10 pairs of flights chosen over other flights to be cancelled. The airline noted that a significant delay to this flight (as was expected) would likely have resulted in a last minute cancellation if the aircraft could not leave or return to London Heathrow before the night jet ban started, hence this flight met the criteria set out above in comparison to other flights.

Having reviewed the substantial amount of supporting information provided by the air carrier in this case and considered the complex circumstances of this disruption; this office is satisfied that British Airways approached the cancellation in a fair and reasonable manner. In summary we accept that the fog both at the airport and at altitude on the approach to the airport caused knock on aircraft flow restrictions which in turn created a capacity problem which resulted in the air carrier having to make a necessary operational decision to cancel your flight (together with 10 others) as there would not be sufficient slots available at the airport to operate the flights had they remained scheduled. Therefore, this office accepts that British Airways has satisfied both of the criteria contained in Article 5(3) of the Regulation and is exempted from paying compensation to passengers affected by the cancellation of flight BA829 on the 9th April 2015.

As regards your other entitlements under the legislation, I note that you were re-routed on the next alternative flight in accordance with the Regulation. It is our understanding that you were provided with assistance during the disruption. Please be advised however that in the event that this assistance was inadequate you are entitled to recover any expenses you may have incurred in arranging your own meals, refreshments, telephone calls, accommodation and transfers under Regulation 261. Therefore if you incurred any expenses for these particular items please revert to us enclosing copies of your related receipts and we will engage with British Airways on your behalf.

Given that all matters which fall within our remit of enforcement have now been addressed, it is my intention to close my file on this matter. Once again please accept my apologies for the delay in providing these conclusions to you. I trust that the above concludes matters to your satisfaction.

Yours sincerely,

So, now we know.