Computer outage grounds hundreds of BA flights in London

LONDON (AP) — British Airways canceled all flights from London's Heathrow and Gatwick airports on Saturday as a global IT failure upended the travel plans of tens of thousands of people on a busy U.K. holiday weekend.

Passengers at Heathrow reported long lines at check-in counters and the failure of both the airline's website and its mobile app.

Passenger Phillip Norton tweeted video of an announcement from a pilot to passengers at Rome's Fiumicino airport, saying the problem affects the system that regulates what passengers and baggage go on which aircraft.

Airlines depend on huge, overlapping and complex IT systems to do just about everything, from operating flights to handling ticketing, boarding, websites and mobile-phone apps.

[...] after years of rapid consolidation in the business, these computer systems may be a hodgepodge of parts of varying ages and from different merger partners, all layered on top of each other.

In August 2016, Delta planes around the world were grounded when an electrical component failed and led to a shutdown of the transformer that provides power to the airline's data center.