People on FlyerTalk are reporting that the BA systems are down, as of around 6 pm there. Some planes are unable to take off because. The pilots cannot use the load calculator software, and people are unable to get into the website to check in for a flight, make a new booking, or change an existing one.
Just FYI if you have a BA flight coming up or want to book one.
This happened on Feb. 22 as well, although I don’t know if it affected flight departures.