British Airways have refused to pay my claim for compensation when my flight BA877 from TLL to LHR on 15 June 2018 suffered a technical issue on arrival in Tallin, ahead of its 21:30 departure time. The captain himself came to the podium at the gate and told us there was a warning light for the avionics system and an engineer had been called. He eventually arrived and sometime later the captain returned to tell us that they needed to take the plane to a remote part of the airport to perform some engine tests. Eventually, at 00:22, we were told we would be going to a hotel. Our flight was rescheduled for the next day at 2pm and we finally arrived a Heathrow on the 16th at 15:11. The captain told us that although the issue had been fixed, we couldn't fly that evening as LHR was closed for the night and the crew also needed 12 hours of rest. So on paper that's a delayed arrival of well over 3 hours. No brainer you would think.

But BA refused my claim: Your claim for EU has been refused because BA0877 on 15 June was delayed because of operational circumstances outside of our control, which prevented the aircraft operating as scheduled. Under EU legislation, I’m afraid we’re not liable for a compensation payment in this situation.

I am still waiting for BA to reply to my question as to why they think that is the case, but a couple of tweets to them in the meantime has resulted in these responses:

We're sorry you're disappointed by this. I'm afraid the technical delay only contributed 171 minutes of the overall flight delay on BA0877. This does mean it's not payable under EU regulations.

To be eligible for EU compensation, the technical delay minutes would need to be 180 minutes or more. The total length of the delay wouldn't make this eligible and I'm sorry for the disappointment this has caused.

I have just gone through the actual statue and its interpretation guide and there is no mention of the amount of time a technical issue contributes to a delay. All I can find is references to how the delay is based on the actual time of arrival versus the scheduled time. I suspect they are going to state the LHR's refusal to let them land in the early hours and/or their staff running out of hours is an exceptional circumstance. If they do, I'd argue that LHR's night-time closures is a fact that they need to take into account when planning, as is their staff rest policy. Neither are therefore exceptional circumstance, nor was the technical issue that caused the original delay.

While I wait for BA's official response, can any one provide any more insights or advice?