Learn English: Oops! London Airport's Computer Problem! (easy)

There was a computer problem at the airports in London, so some airplanes couldn't take off!

The problem was with a special radar that helps planes fly safely, but it was fixed quickly.

Only the airplanes going away had problems; the planes coming in landed just fine.

Remember that time the airport had a big power problem? This was a different kind of problem but caused some delays.