to divert flight after flight when its computers failed, saddling one of the world's busiest hubs. an hour ago, a spokesman told cnn they have ruled out a cyberattack. and they say it was a hiccup in their state-of-the-art computers. cnn aviation correspondent rene marsh joins us now. even if it wasn't a cyberattack, this does expose just how easily our way of managing airplanes in this computerized world can easily implode. >> you're absolutely right. it truly is a vulnerable that makes a lot of people uncomfortable. if you're flying through london, one thing is certain today, you can expect delays for hours to come. about 100 flights in and out of heathrow, a major international hub, canceled. and even more delays. and then there's the ripple effect. it's all because of this computer failure, a real-life demonstration of just how a