Originally Posted by corporate-wage-slave

It's always good to put the airport code. Not only does it make it easier for those of us who have not yet memorised the timetable, it also helps with the reason for the delay. Which you will find in this thread:
https://www.flyertalk.com/forum/brit...l#post35324567
and that thread is the best source to find the reason. In this case NCE-LHR follows on as a rotational cancellation from BA356, which in turn is marked as DAMN - so BA does not think it's OK for compensation, post 1 in that thread explains this more, but I'm presuming either a lightning strike or water damage. Now there may be more to this story, so I'm not taking this as necessarily a No for EC261, but it's for sure you need to go through EC261 to CEDR to find out the details, and there may be something in there which allows the "all reasonable measures" issue to be explored.

This would in any event only be one, the delay - if 2hr 47 from the schedule of BA349 - is under the 3 hour minima for delay compensation, but over the limits for cancellation, should extraordinary circumstances not apply.