Time stop

A Time Stop is a simple trick created by the Time Lords. A Time Stop was able to stop single objects in time, making them appear to have "frozen".

Missy, the latest incarnation of the Master, used her device to activate a Time Stop on all the planes around the entire Earth in order to gain UNIT and Clara Oswald's attention when the Doctor went missing.

The Time Stop confused Clara at first, making her tell her students at Coal Hill School to turn on their phones and add the hashtag ThePlanesHaveStopped to News websites and Twitter.